游戏

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Visual C++

raiders3d_2b.cpp：源码内容
							// RAIDERS3D_2b.CPP - 3D star raiders game version 2.0, 16-bit 
// READ THIS!
// To compile make sure to include DDRAW.LIB, DSOUND.LIB,
// DINPUT.LIB, DINPUT8.LIB, WINMM.LIB in the project link list, and of course 
// the C++ source modules T3DLIB1-7.CPP and the headers T3DLIB1-7.H
// be in the working directory of the compiler
// INCLUDES ///////////////////////////////////////////////
#define DEBUG_OFF
#define INITGUID       // make sure al the COM interfaces are available
                       // instead of this you can include the .LIB file
                       // DXGUID.LIB
#define WIN32_LEAN_AND_MEAN  
#include <windows.h>   // include important windows stuff
#include <windowsx.h> 
#include <mmsystem.h>
#include <iostream.h> // include important C/C++ stuff
#include <conio.h>
#include <stdlib.h> 
#include <malloc.h> 
#include <memory.h>
#include <string.h> 
#include <stdarg.h>
#include <stdio.h> 
#include <math.h>
#include <io.h>
#include <fcntl.h>
 
#include <ddraw.h>  // directX includes
#include <dsound.h>
#include <dmksctrl.h>
#include <dmusici.h>
#include <dmusicc.h>
#include <dmusicf.h>
#include <dinput.h>
#include "T3DLIB1.h" // game library includes
#include "T3DLIB2.h"
#include "T3DLIB3.h"
#include "T3DLIB4.h"
#include "T3DLIB5.h"
#include "T3DLIB6.h"
#include "T3DLIB7.h"
// DEFINES ////////////////////////////////////////////////
// defines for windows interface
#define WINDOW_CLASS_NAME "WIN3DCLASS"  // class name
#define WINDOW_TITLE      "T3D Graphics Console Ver 2.0"
#define WINDOW_WIDTH      800  // size of window
#define WINDOW_HEIGHT     600
#define WINDOW_BPP        16    // bitdepth of window (8,16,24 etc.)
                                // note: if windowed and not
                                // fullscreen then bitdepth must
                                // be same as system bitdepth
                                // also if 8-bit the a pallete
                                // is created and attached
   
#define WINDOWED_APP      0     // 0 not windowed, 1 windowed
// 3D engine constants for overlay star field
#define NEAR_Z            10    // the near clipping plane
#define FAR_Z             2000  // the far clipping plane    
#define VIEW_DISTANCE      400  // viewing distance from viewpoint 
                                // this gives a field of view of 90 degrees
                                // when projected on a window of 800 wide
// create some constants for ease of access
#define AMBIENT_LIGHT_INDEX   0 // ambient light index
#define INFINITE_LIGHT_INDEX  1 // infinite light index
#define POINT_LIGHT_INDEX     2 // point light index
#define POINT_LIGHT2_INDEX    3 // point light index
#define SPOT_LIGHT2_INDEX     4 // spot light index
// alien defines
#define NUM_ALIENS            16 // total number of ALIEN fighters 
// states for aliens
#define ALIEN_STATE_DEAD      0  // alien is dead
#define ALIEN_STATE_ALIVE     1  // alien is alive
#define ALIEN_STATE_DYING     2  // alien is in process of dying
// star defines
#define NUM_STARS           256  // number of stars in sim
// game state defines
#define GAME_STATE_INIT       0  // game initializing for first time
#define GAME_STATE_RESTART    1  // game restarting after game over
#define GAME_STATE_RUN        2  // game running normally
#define GAME_STATE_DEMO       3  // game in demo mode
#define GAME_STATE_OVER       4  // game over
#define GAME_STATE_EXIT       5  // game state exit
#define MAX_MISSES_GAME_OVER  25 // miss this many and it's game over man
// interface text positions
#define TPOS_SCORE_X          346  // players score
#define TPOS_SCORE_Y          4
#define TPOS_HITS_X           250  // total kills
#define TPOS_HITS_Y           36
#define TPOS_ESCAPED_X        224  // aliens that have escaped
#define TPOS_ESCAPED_Y        58
#define TPOS_GLEVEL_X         430 // diff level of game
#define TPOS_GLEVEL_Y         58
#define TPOS_SPEED_X          404 // diff level of game
#define TPOS_SPEED_Y          36
#define TPOS_GINFO_X          400  // general information
#define TPOS_GINFO_Y          240
#define TPOS_ENERGY_X         158 // weapon energy level
#define TPOS_ENERGY_Y         6
// player defines
#define CROSS_START_X         0
#define CROSS_START_Y         0
#define CROSS_WIDTH           56
#define CROSS_HEIGHT          56
// font display stuff
#define FONT_HPITCH           12  // space between chars
#define FONT_VPITCH           14  // space between lines
// difficulty stuff
#define DIFF_RATE             (float)(.001f)  // rate to advance  difficulty per frame
#define DIFF_PMAX             75            
// explosion stuff
#define NUM_EXPLOSIONS        16
// PROTOTYPES /////////////////////////////////////////////
// game console funtions
int Game_Init(void *parms=NULL);
int Game_Shutdown(void *parms=NULL);
int Game_Main(void *parms=NULL);
// starfield functions
void Draw_Starfield(UCHAR *video_buffer, int lpitch);
void Move_Starfield(void);
void Init_Starfield(void);
// alien functions
void Process_Aliens(void);
void Draw_Aliens(void);
void Init_Aliens(void);
int  Start_Alien(void);
// explosions
int Start_Mesh_Explosion(OBJECT4DV2_PTR obj, // object to destroy
                         MATRIX4X4_PTR mrot, // initial orientation
                         int detail,         // the detail level,1 highest detail
                         float rate,         // velocity of explosion shrapnel
                         int lifetime);      // total lifetime of explosion
void Draw_Mesh_Explosions(void);
// font functions
int Draw_Bitmap_Font_String(BOB_PTR font, 
                            int x, int y, 
                            char *string, 
                            int hpitch, int vpitch, 
                            LPDIRECTDRAWSURFACE7 dest); 
int Load_Bitmap_Font(char *fontfile, BOB_PTR font);
// TYPES ///////////////////////////////////////////////////
// this a 3D star
typedef struct STAR3D_TYP
        {
        USHORT color;     // color of point 16-bit
        float x,y,z;      // coordinates of point in 3D
        } STAR3D, *STAR3D_PTR;
// ALIEN fighter object
typedef struct ALIEN_TYP
        {
        int      state;  // state of this ALIEN fighter
        int      count;  // generic counter
        int      aux;    // generic auxialiary var
        POINT3D  pos;    // position of ALIEN fighter
        VECTOR3D vel;    // velocity of ALIEN fighter
        VECTOR3D rot;    // rotational velocities
        VECTOR3D ang;    // current orientation
        } ALIEN, *ALIEN_PTR;
// GLOBALS /////////////////////////////////////////////////
HWND main_window_handle           = NULL; // save the window handle
HINSTANCE main_instance           = NULL; // save the instance
char buffer[2048];                        // used to print text
// initialize camera position and direction
POINT4D  cam_pos    = {0,0,0,1};
POINT4D  cam_target = {0,0,0,1};
VECTOR4D cam_dir    = {0,0,0,1};
// all your initialization code goes here...
VECTOR4D vscale={1.0,1.0,1.0,1}, 
         vpos = {0,0,0,1}, 
         vrot = {0,0,0,1};
CAM4DV1        cam;       // the single camera
RENDERLIST4DV2 rend_list; // the render list
// color constants for line drawing
USHORT rgb_green,  
       rgb_white,
       rgb_red,
       rgb_blue;
// colors for lights
RGBAV1 white, light_gray, gray, black, red, green, blue;
// music and sound stuff
int main_track_id      = -1, // main music track id
    laser_id           = -1, // sound of laser pulse
    explosion_id       = -1, // sound of explosion
    flyby_id           = -1, // sound of ALIEN fighter flying by
    game_over_id       = -1, // game over
    ambient_systems_id = -1; // ambient sounds
// star globals
STAR3D stars[NUM_STARS]; // the starfield
// player and game globals
int player_z_vel = 4; // virtual speed of viewpoint/ship
float cross_x = 0, // cross hairs
      cross_y = 0; 
int cross_x_screen  = WINDOW_WIDTH/2,   // used for cross hair
    cross_y_screen  = WINDOW_HEIGHT/2, 
    target_x_screen = WINDOW_WIDTH/2,   // used for targeter
    target_y_screen = WINDOW_HEIGHT/2;
int escaped        = 0;   // tracks number of missed ships
int hits           = 0;   // tracks number of hits
int score          = 0;   // take a guess :)
int weapon_energy  = 100; // weapon energy
int weapon_active  = 0;   // tracks if weapons are energized
int game_state           = GAME_STATE_INIT; // state of game
int game_state_count1    = 0;               // general counters
int game_state_count2    = 0;
int restart_state        = 0;               // state when game is restarting
int restart_state_count1 = 0;               // general counter
// diffiuculty
float  diff_level    = 1;                   // difficulty level used in velocity and probability calcs
// alien globals
ALIEN      aliens[NUM_ALIENS];   // the ALIEN fighters
OBJECT4DV2 obj_alien;            // the master object
// explosions
OBJECT4DV2 explobj[NUM_EXPLOSIONS]; // the explosions
// game imagery assets
BOB cockpit;               // the cockpit image
BOB starscape;             // the background starscape
BOB tech_font;             // the bitmap font for the engine
BOB crosshair;             // the player's cross hair
// these are the positions of the energy binding on the main lower control panel
POINT2D energy_bindings[6] = { {342, 527}, {459, 527}, 
                               {343, 534}, {458, 534}, 
                               {343, 540}, {458, 540} };
// these hold the positions of the weapon burst which use lighting too
// the starting points are known, but the end points are computed on the fly
// based on the cross hair
POINT2D weapon_bursts[4] = { {78, 500}, {0,0},     // left energy weapon
                             {720, 500}, {0,0} };  // right energy weapon
int px = 0, py = 0, pz = 500 ; // debug stuff for object tracking
// FUNCTIONS //////////////////////////////////////////////
LRESULT CALLBACK WindowProc(HWND hwnd, 
						    UINT msg, 
                            WPARAM wparam, 
                            LPARAM lparam)
{
// this is the main message handler of the system
PAINTSTRUCT	ps;		   // used in WM_PAINT
HDC			hdc;	   // handle to a device context
// what is the message 
switch(msg)
	{	
	case WM_CREATE: 
        {
		// do initialization stuff here
		return(0);
		} break;
    case WM_PAINT:
         {
         // start painting
         hdc = BeginPaint(hwnd,&ps);
         // end painting
         EndPaint(hwnd,&ps);
         return(0);
        } break;
	case WM_DESTROY: 
		{
		// kill the application			
		PostQuitMessage(0);
		return(0);
		} break;
	default:break;
    } // end switch
// process any messages that we didn't take care of 
return (DefWindowProc(hwnd, msg, wparam, lparam));
} // end WinProc
// WINMAIN ////////////////////////////////////////////////
int WINAPI WinMain(	HINSTANCE hinstance,
					HINSTANCE hprevinstance,
					LPSTR lpcmdline,
					int ncmdshow)
{
// this is the winmain function
WNDCLASS winclass;	// this will hold the class we create
HWND	 hwnd;		// generic window handle
MSG		 msg;		// generic message
HDC      hdc;       // generic dc
PAINTSTRUCT ps;     // generic paintstruct
// first fill in the window class stucture
winclass.style			= CS_DBLCLKS | CS_OWNDC | 
                          CS_HREDRAW | CS_VREDRAW;
winclass.lpfnWndProc	= WindowProc;
winclass.cbClsExtra		= 0;
winclass.cbWndExtra		= 0;
winclass.hInstance		= hinstance;
winclass.hIcon			= LoadIcon(NULL, IDI_APPLICATION);
winclass.hCursor		= LoadCursor(NULL, IDC_ARROW);
winclass.hbrBackground	= (HBRUSH)GetStockObject(BLACK_BRUSH);
winclass.lpszMenuName	= NULL; 
winclass.lpszClassName	= WINDOW_CLASS_NAME;
// register the window class
if (!RegisterClass(&winclass))
	return(0);
// create the window, note the test to see if WINDOWED_APP is
// true to select the appropriate window flags
if (!(hwnd = CreateWindow(WINDOW_CLASS_NAME, // class
						  WINDOW_TITLE,	 // title
						  (WINDOWED_APP ? (WS_OVERLAPPED | WS_SYSMENU | WS_CAPTION) : (WS_POPUP | WS_VISIBLE)),
					 	  0,0,	   // x,y
						  WINDOW_WIDTH,  // width
                          WINDOW_HEIGHT, // height
						  NULL,	   // handle to parent 
						  NULL,	   // handle to menu
						  hinstance,// instance
						  NULL)))	// creation parms
return(0);
// save the window handle and instance in a global
main_window_handle = hwnd;
main_instance      = hinstance;
// resize the window so that client is really width x height
if (WINDOWED_APP)
{
// now resize the window, so the client area is the actual size requested
// since there may be borders and controls if this is going to be a windowed app
// if the app is not windowed then it won't matter
RECT window_rect = {0,0,WINDOW_WIDTH-1,WINDOW_HEIGHT-1};
// make the call to adjust window_rect
AdjustWindowRectEx(&window_rect,
     GetWindowStyle(main_window_handle),
     GetMenu(main_window_handle) != NULL,  
     GetWindowExStyle(main_window_handle));
// save the global client offsets, they are needed in DDraw_Flip()
window_client_x0 = -window_rect.left;
window_client_y0 = -window_rect.top;
// now resize the window with a call to MoveWindow()
MoveWindow(main_window_handle,
           0, // x position
           0, // y position
           window_rect.right - window_rect.left, // width
           window_rect.bottom - window_rect.top, // height
           FALSE);
// show the window, so there's no garbage on first render
ShowWindow(main_window_handle, SW_SHOW);
} // end if windowed
// perform all game console specific initialization
Game_Init();
// disable CTRL-ALT_DEL, ALT_TAB, comment this line out 
// if it causes your system to crash
SystemParametersInfo(SPI_SCREENSAVERRUNNING, TRUE, NULL, 0);
// enter main event loop
while(1)
	{
	if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
		{ 
		// test if this is a quit
        if (msg.message == WM_QUIT)
           break;
	
		// translate any accelerator keys
		TranslateMessage(&msg);
		// send the message to the window proc
		DispatchMessage(&msg);
		} // end if
    
    // main game processing goes here
    Game_Main();
	} // end while
// shutdown game and release all resources
Game_Shutdown();
// enable CTRL-ALT_DEL, ALT_TAB, comment this line out 
// if it causes your system to crash
SystemParametersInfo(SPI_SCREENSAVERRUNNING, FALSE, NULL, 0);
// return to Windows like this
return(msg.wParam);
} // end WinMain
////////////////////////////////////////////////////////////////////
void Render_Energy_Bindings(POINT2D_PTR bindings, // array containing binding positions in the form
                                                  // start point, end point, start point, end point...
                            int num_bindings,     // number of energy bindings to render 1-3
                            int num_segments,     // number of segments to randomize bindings into
                            int amplitude,        // amplitude of energy binding
                            int color,            // color of bindings
                            UCHAR *video_buffer,  // video buffer to render
                            int lpitch)           // memory pitch of buffer
{
// this functions renders the energy bindings across the main exterior energy
// transmission emitters :) Basically, the function takes two points in 2d then
// it anchors a line at the two ends and randomly walks from end point to the
// other by breaking the line into segments and then randomly modulating the y position
// and amount amplitude +-, maximum number of segments 16
POINT2D segments[17]; // to hold constructed segments after construction
// render each binding
for (int index = 0; index < num_bindings; index++)
    {
    // store starting and ending positions
    
    // starting position
    segments[0] = bindings[index*2];
    
    // ending position
    segments[num_segments] = bindings[index*2+1];
    // compute vertical gradient, so if y positions of endpoints are
    // greatly different bindings will be modulated using the straight line
    // as a basis
    float dyds = (segments[num_segments].y - segments[0].y) / (float)num_segments;
    float dxds = (segments[num_segments].x - segments[0].x) / (float)num_segments;
    // now build up segments
    for (int sindex = 1; sindex < num_segments; sindex++)
        {
        segments[sindex].x = segments[sindex-1].x + dxds;
        segments[sindex].y = segments[0].y + sindex*dyds + RAND_RANGE(-amplitude, amplitude);
        } // end for segment            
    // draw binding
    for (sindex = 0; sindex < num_segments; sindex++)
        Draw_Line16(segments[sindex].x, segments[sindex].y, 
                    segments[sindex+1].x, segments[sindex+1].y,
                    color, video_buffer, lpitch); 
    } // end for index
} // end Render_Energy_Binding
////////////////////////////////////////////////////////////////////
void Render_Weapon_Bursts(POINT2D_PTR burstpoints, // array containing energy burst positions in the form
                                                   // start point, end point, start point, end point...
                            int num_bursts,
                            int num_segments,     // number of segments to randomize bindings into
                            int amplitude,        // amplitude of energy binding
                            int color,            // color of bindings
                            UCHAR *video_buffer,  // video buffer to render
                            int lpitch)           // memory pitch of buffer
{
// this functions renders the weapon energy bursts from the weapon emitter or wherever
// function derived from Render_Energy_Binding, but generalized 
// Basically, the function takes two points in 2d then
// it anchors a line at the two ends and randomly walks from end point to the
// other by breaking the line into segments and then randomly modulating the x,y position
// and amount amplitude +-, maximum number of segments 16
POINT2D segments[17]; // to hold constructed segments after construction
// render each energy burst
for (int index = 0; index < num_bursts; index++)
    {
    // store starting and ending positions
    
    // starting position
    segments[0] = burstpoints[index*2];
    
    // ending position
    segments[num_segments] = burstpoints[index*2+1];
    // compute horizontal/vertical gradients, so we can modulate the lines 
    // on the proper trajectory
    float dyds = (segments[num_segments].y - segments[0].y) / (float)num_segments;
    float dxds = (segments[num_segments].x - segments[0].x) / (float)num_segments;
    // now build up segments
    for (int sindex = 1; sindex < num_segments; sindex++)
        {
        segments[sindex].x = segments[0].x + sindex*dxds + RAND_RANGE(-amplitude, amplitude);
        segments[sindex].y = segments[0].y + sindex*dyds + RAND_RANGE(-amplitude, amplitude);
        } // end for segment            
    // draw binding
    for (sindex = 0; sindex < num_segments; sindex++)
        Draw_Line16(segments[sindex].x, segments[sindex].y, 
                    segments[sindex+1].x, segments[sindex+1].y,
                    color, video_buffer, lpitch); 
    } // end for index
} // end Render_Weapons_Bursts
///////////////////////////////////////////////////////////////
int Load_Bitmap_Font(char *fontfile, BOB_PTR font)
{
// this is a semi generic font loader...
// expects the file name of a font in a template that is 
// 4 rows of 16 cells, each character is 16x14, and cell 0 is the space character
// characters from 32 to 95, " " to "-", suffice for 90% of text work
// load the font bitmap template
if (!Load_Bitmap_File(&bitmap16bit, fontfile))
   return(0);
// create the bob that will hold the font, use a bob for speed, we can use the 
// hardware blitter
Create_BOB(font, 0,0,16,14,64, BOB_ATTR_VISIBLE | BOB_ATTR_SINGLE_FRAME, DDSCAPS_SYSTEMMEMORY, 0, 16); 
// load all the frames
for (int index=0; index < 64; index++)
     Load_Frame_BOB16(font, &bitmap16bit,index,index%16,index/16,BITMAP_EXTRACT_MODE_CELL);
// unload the bitmap file
Unload_Bitmap_File(&bitmap16bit);
// return success
return(1);
} // end Load_Bitmap_Font
///////////////////////////////////////////////////////////////
int Draw_Bitmap_Font_String(BOB_PTR font,  // pointer to bob containing font
                            int x, int y,  // screen position to render
                            char *string,  // string to render
                            int hpitch, int vpitch, // horizontal and vertical pitch
                            LPDIRECTDRAWSURFACE7 dest) // destination surface
{
// this function draws a string based on a 64 character font sent in as a bob
// the string will be drawn at the given x,y position with intercharacter spacing
// if hpitch and a interline spacing of vpitch
// are things semi valid?
if (!string || !dest)
   return(0);
// loop and render
for (int index = 0; index < strlen(string); index++)
    {
    // set the position and character
    font->x = x;
    font->y = y;
    font->curr_frame = string[index] - 32;
    // test for overflow set to space
    if (font->curr_frame > 63 || font->curr_frame < 0) font->curr_frame = 0;
    // render character (i hate making a function call!)
    Draw_BOB16(font, dest);
    // move position
    x+=hpitch;
    } // end for index
// return success
return(1);
} // end Draw_Bitmap_Font_String
/////////////////////////////////////////////////////////
int Start_Alien(void)
{
// this function hunts in the alien list, finds an available alien and 
// starts it up
for (int index = 0; index < NUM_ALIENS; index++)
    {
    // is this alien available?
    if (aliens[index].state == ALIEN_STATE_DEAD)
       {
       // clear any residual data
       memset((void *)&aliens[index], 0, sizeof (ALIEN) );
       // start alien up
       aliens[index].state = ALIEN_STATE_ALIVE;
       
       // select random position in bounding volume
       aliens[index].pos.x = RAND_RANGE(-1000,1000);
       aliens[index].pos.y = RAND_RANGE(-1000,1000);
       aliens[index].pos.z = 20000;
       
       // select velocity based on difficulty level
       aliens[index].vel.x = RAND_RANGE(-10,10);
       aliens[index].vel.y = RAND_RANGE(-10,10);
       aliens[index].vel.z = -(10*diff_level+rand()%200);
       // set rotation rate for z axis only
       aliens[index].rot.z = RAND_RANGE(-5,5);
 
       // return the index
       return(index);
       } // end if   
    } // end for index
// failure
return(-1);
} // end Start_Alien
/////////////////////////////////////////////////////////
void Init_Aliens(void)
{
// initializes all the ALIEN fighters to a known state
for (int index = 0; index < NUM_ALIENS; index++)
    {
    // zero ALIEN fighter out
    memset((void *)&aliens[index], 0, sizeof (ALIEN) );
    // set any other specific info now...
    aliens[index].state = ALIEN_STATE_DEAD;
    } // end for
} // end Init_Aliens
/////////////////////////////////////////////////////////
void Draw_Aliens(void)
{
// this function draws all the active ALIEN fighters
MATRIX4X4 mrot; // used to transform objects
for (int index = 0; index < NUM_ALIENS; index++)
    {
    // which state is alien in
    switch(aliens[index].state)
          {
          // is the alien dead? if so move on
          case ALIEN_STATE_DEAD: break;
          // is the alien alive?
          case ALIEN_STATE_ALIVE:
          case ALIEN_STATE_DYING:
          {
          // reset the object (this only matters for backface and object removal)
          Reset_OBJECT4DV2(&obj_alien);
          // generate rotation matrix around y axis
          Build_XYZ_Rotation_MATRIX4X4(aliens[index].ang.x, aliens[index].ang.y, aliens[index].ang.z ,&mrot);
         
          // rotate the local coords of the object
          Transform_OBJECT4DV2(&obj_alien, &mrot, TRANSFORM_LOCAL_TO_TRANS,1);
          // set position of constant shaded cube
          obj_alien.world_pos.x = aliens[index].pos.x;
          obj_alien.world_pos.y = aliens[index].pos.y;
          obj_alien.world_pos.z = aliens[index].pos.z;
          // attempt to cull object
          if (!Cull_OBJECT4DV2(&obj_alien, &cam, CULL_OBJECT_XYZ_PLANES))
             {
             // perform world transform
             Model_To_World_OBJECT4DV2(&obj_alien, TRANSFORM_TRANS_ONLY);
             // insert the object into render list
             Insert_OBJECT4DV2_RENDERLIST4DV2(&rend_list, &obj_alien,0);
             } // end if 
          // ok, now test for collision with energy bursts, strategy is as follows
          // we will project the bounding box of the object into screen space to coincide with
          // the energy burst on the screen, if there is an overlap then the target is hit
          // simply need to do a few transforms, this kinda sucks that we are going to do this work
          // 2x, but the problem is that the graphics pipeline knows nothing about collision etc.,
          // so we can't "get to" the information me want since we are ripping the objects apart
          // and passing them down the pipeline for a later world to camera transform, thus you
          // may want to think about this problem when making your own game, how tight to couple
          // collision and the engine, HOWEVER, the only reason we are having a problem at all is that
          // we want to use the screen coords of the energy burst this is fine, but a more effective method
          // would be to compute the 3D world coords of where the energy burst is firing and then project
          // that parallelpiped in 3D space to see where the player is trying to fire, this is a classic
          // problem with screen picking, hence, in the engine, when an object is rendered sometimes its 
          // a good idea to track somekind of collision boundary in screen coords that can be used later
          // for "object picking" and collision, anyway, let's do it the easy way, but the long way....
          // first is the player firing weapon?
          if (weapon_active)
             {
             // we need 4 transforms total, first we need all our points in world coords,
             // then we need camera coords, then perspective coords, then screen coords
             // we need to transform 2 points: the center and a point lying on the surface of the  
             // bounding sphere, as long as the 
             POINT4D pbox[4], // bounding box coordinates, center points, surrounding object
                              // denoted by X's, we need to project these to screen coords
                              // ....X.... 
                              // . |   | .
                              // X |-O-| X
                              // . |   | . 
                              // ....X....
                              // we will use the average radius as the distance to each X from the center
                     presult; // used to hold temp results
             // world to camera transform
             // transform center point only
             Mat_Mul_VECTOR4D_4X4(&obj_alien.world_pos, &cam.mcam, &presult);
             // result holds center of object in camera coords now
             // now we are in camera coords, aligned to z-axis, compute radial point axis aligned
             // bounding box points
             // x+r, y, z
             pbox[0].x = presult.x + obj_alien.avg_radius[obj_alien.curr_frame];
             pbox[0].y = presult.y;
             pbox[0].z = presult.z;
             pbox[0].w = 1;        
             // x-r, y, z
             pbox[1].x = presult.x - obj_alien.avg_radius[obj_alien.curr_frame];
             pbox[1].y = presult.y;
             pbox[1].z = presult.z;
             pbox[1].w = 1;     
             // x, y+r, z
             pbox[2].x = presult.x;
             pbox[2].y = presult.y + obj_alien.avg_radius[obj_alien.curr_frame];
             pbox[2].z = presult.z;
             pbox[2].w = 1;     
             // x, y-r, z
             pbox[3].x = presult.x;
             pbox[3].y = presult.y - obj_alien.avg_radius[obj_alien.curr_frame];
             pbox[3].z = presult.z;
             pbox[3].w = 1;     
             // now we are ready to project the points to screen space
             float alpha = (0.5*cam.viewport_width-0.5);
             float beta  = (0.5*cam.viewport_height-0.5);
             // loop and process each point
             for (int bindex=0; bindex < 4; bindex++)
                 {
                 float z = pbox[bindex].z;
                 // perspective transform first
                 pbox[bindex].x = cam.view_dist*pbox[bindex].x/z;
                 pbox[bindex].y = cam.view_dist*pbox[bindex].y*cam.aspect_ratio/z;
                 // z = z, so no change
                 // screen projection
                 pbox[bindex].x =  alpha*pbox[bindex].x + alpha; 
                 pbox[bindex].y = -beta*pbox[bindex].y + beta;
                 } // end for bindex
#ifdef DEBUG_ON
             // now we have the 4 points is screen coords and we can test them!!! ya!!!!
             Draw_Clip_Line16(pbox[0].x, pbox[2].y, pbox[1].x, pbox[2].y, rgb_red, back_buffer, back_lpitch);
             Draw_Clip_Line16(pbox[0].x, pbox[3].y, pbox[1].x, pbox[3].y, rgb_red, back_buffer, back_lpitch);
             Draw_Clip_Line16(pbox[0].x, pbox[2].y, pbox[0].x, pbox[3].y, rgb_red, back_buffer, back_lpitch);
             Draw_Clip_Line16(pbox[1].x, pbox[2].y, pbox[1].x, pbox[3].y, rgb_red, back_buffer, back_lpitch);
#endif
             // test for collision
             if ((cross_x_screen > pbox[1].x) && (cross_x_screen < pbox[0].x) &&
                 (cross_y_screen > pbox[2].y) && (cross_y_screen < pbox[3].y) )
                {
                Start_Mesh_Explosion(&obj_alien, // object to blow
                                     &mrot,      // initial orientation
                                     3,          // the detail level,1 highest detail
                                     .5,         // velocity of explosion shrapnel
                                     100);       // total lifetime of explosion         
                // remove from simulation
                aliens[index].state = ALIEN_STATE_DEAD;
                // make some sound
                DSound_Play(explosion_id);
                // increment hits
                hits++;
              
                // take into consideration the z, the speed, the level, blah blah
                score += (int)((diff_level*10 + obj_alien.world_pos.z/10));
                } // end if
        
             } // end if weapon active
          } break;
         
          default: break;
          } // end switch
    } // end for index
// debug code
#ifdef DEBUG_ON
// reset the object (this only matters for backface and object removal)
Reset_OBJECT4DV2(&obj_alien);
static int ang_y = 0;
// generate rotation matrix around y axis
Build_XYZ_Rotation_MATRIX4X4(0, ang_y++, 0 ,&mrot);
         
// rotate the local coords of the object
Transform_OBJECT4DV2(&obj_alien, &mrot, TRANSFORM_LOCAL_TO_TRANS,1);
// set position of constant shaded cube
obj_alien.world_pos.x = px;
obj_alien.world_pos.y = py;
obj_alien.world_pos.z = pz;
// perform world transform
Model_To_World_OBJECT4DV2(&obj_alien, TRANSFORM_TRANS_ONLY);
// insert the object into render list
Insert_OBJECT4DV2_RENDERLIST4DV2(&rend_list, &obj_alien,0);
#endif
} // end Draw_Aliens
//////////////////////////////////////////////////////////
void Draw_Mesh_Explosions(void)
{
// this function draws the mesh explosions
MATRIX4X4 mrot; // used to transform objects
// draw the explosions, note we do NOT cull them
for (int eindex = 0; eindex < NUM_EXPLOSIONS; eindex++)
    {
    // is the mesh explosions active
    if ((explobj[eindex].state & OBJECT4DV2_STATE_ACTIVE))
       {
       // reset the object
       Reset_OBJECT4DV2(&explobj[eindex]);
       // generate rotation matrix 
       Build_XYZ_Rotation_MATRIX4X4(0, 0, 0 ,&mrot);
         
       // rotate the local coords of the object
       Transform_OBJECT4DV2(&explobj[eindex], &mrot, TRANSFORM_LOCAL_TO_TRANS,1);
       // perform world transform
       Model_To_World_OBJECT4DV2(&explobj[eindex], TRANSFORM_TRANS_ONLY);
       // insert the object into render list
       Insert_OBJECT4DV2_RENDERLIST4DV2(&rend_list, &explobj[eindex],0);
   
       // now animate the mesh
       VECTOR4D_PTR trajectory = (VECTOR4D_PTR)explobj[eindex].ivar1;
       
       for (int pindex = 0; pindex < explobj[eindex].num_polys; pindex++)
           {
           // vertex 0
           VECTOR4D_Add(&explobj[eindex].vlist_local[pindex*3 + 0].v,
                        &trajectory[pindex*2+0], 
                        &explobj[eindex].vlist_local[pindex*3 + 0].v);
           // vertex 1
           VECTOR4D_Add(&explobj[eindex].vlist_local[pindex*3 + 1].v,
                        &trajectory[pindex*2 + 0], 
                        &explobj[eindex].vlist_local[pindex*3 + 1].v);
           // vertex 2
           VECTOR4D_Add(&explobj[eindex].vlist_local[pindex*3 + 2].v,
                        &trajectory[pindex*2 + 0], 
                        &explobj[eindex].vlist_local[pindex*3 + 2].v);
           // modulate color
           //explobj[eindex].plist[pindex].color = RGB16Bit(rand()%255,0,0);
           } // end for pindex
      // update counter, test for terminate
      if (--explobj[eindex].ivar2 < 0)
         {
         // reset this object
         explobj[eindex].state  = OBJECT4DV2_STATE_NULL;           
         // release memory of object, but only data that isn't linked to master object
         // local vertex list
         if (explobj[eindex].head_vlist_local)
            free(explobj[eindex].head_vlist_local);
         // transformed vertex list
         if (explobj[eindex].head_vlist_trans)
            free(explobj[eindex].head_vlist_trans);
         // polygon list
         if (explobj[eindex].plist)
            free(explobj[eindex].plist);
         // trajectory list
         if ((VECTOR4D_PTR)(explobj[eindex].ivar1))
            free((VECTOR4D_PTR)explobj[eindex].ivar1);
         // now clear out object completely
         memset((void *)&explobj[eindex], 0, sizeof(OBJECT4DV2));
         } // end if 
       } // end if  
    } // end for eindex
 
} // end Draw_Mesh_Explosions
//////////////////////////////////////////////////////////
int Start_Mesh_Explosion(OBJECT4DV2_PTR obj,  // object to destroy
                         MATRIX4X4_PTR mrot, // initial orientation of object
                         int detail,          // the detail level,1 highest detail
                         float rate,          // velocity of explosion shrapnel
                         int lifetime)        // total lifetime of explosion
{
// this function "blows up" an object, it takes a pointer to the object to
// be destroyed, the detail level of the polyogonal explosion, 1 is high detail, 
// numbers greater than 1 are lower detail, the detail selects the polygon extraction
// stepping, hence a detail of 5 would mean every 5th polygon in the original mesh
// should be part of the explosion, on average no more than 10-50% of the polygons in 
// the original mesh should be used for the explosion; some would be vaporized and
// in a more practical sense, when an object is far, there's no need to have detail
// the next parameter is the rate which is used as a general scale for the explosion
// velocity, and finally lifetime which is the number of cycles to display the explosion
// the function works by taking the original object then copying the core information
// except for the polygon and vertex lists, the function operates by selecting polygon 
// by polygon to be destroyed and then makes a copy of the polygon AND all of it's vertices,
// thus the vertex coherence is completely lost, this is a necessity since each polygon must
// be animated separately by the engine, thus they can't share vertices, additionally at the
// end if the vertex list will be the velocity and rotation information for each polygon
// this is hidden to the rest of the engine, now for the explosion, the center of the object
// is used as the point of origin then a ray is drawn thru each polygon, then each polygon
// is thrown at some velocity with a small rotation rate
// finally the system can only have so many explosions at one time
// step: 1 find an available explosion
for (int eindex = 0; eindex < NUM_EXPLOSIONS; eindex++)
    {
    // is this explosion available?
    if (explobj[eindex].state == OBJECT4DV2_STATE_NULL)
       {
       // copy the object, including the pointers which we will unlink shortly...
       explobj[eindex]                =  *obj;
       explobj[eindex].state = OBJECT4DV2_STATE_ACTIVE | OBJECT4DV2_STATE_VISIBLE;
       // recompute a few things
       explobj[eindex].num_polys      = obj->num_polys/detail;
       explobj[eindex].num_vertices   = 3*obj->num_polys;
       explobj[eindex].total_vertices = 3*obj->num_polys; // one frame only
      
       // unlink/re-allocate all the pointers except the texture coordinates, we can use those, they don't
       // depend on vertex coherence
       // allocate memory for vertex lists
       if (!(explobj[eindex].vlist_local = (VERTEX4DTV1_PTR)malloc(sizeof(VERTEX4DTV1)*explobj[eindex].num_vertices)))
          return(0);
       // clear data
       memset((void *)explobj[eindex].vlist_local,0,sizeof(VERTEX4DTV1)*explobj[eindex].num_vertices);
       if (!(explobj[eindex].vlist_trans = (VERTEX4DTV1_PTR)malloc(sizeof(VERTEX4DTV1)*explobj[eindex].num_vertices)))
           return(0);
       // clear data
       memset((void *)explobj[eindex].vlist_trans,0,sizeof(VERTEX4DTV1)*explobj[eindex].num_vertices);
       // allocate memory for polygon list
       if (!(explobj[eindex].plist = (POLY4DV2_PTR)malloc(sizeof(POLY4DV2)*explobj[eindex].num_polys)))
          return(0);
       // clear data
       memset((void *)explobj[eindex].plist,0,sizeof(POLY4DV2)*explobj[eindex].num_polys);
       // now, we need somewhere to store the vector trajectories of the polygons and their rotational rates
       // so let's allocate an array of VECTOR4D elements to hold this information and then store it
       // in ivar1, therby using ivar as a pointer, this is perfectly fine :)
       // each record will consist of a velocity and a rotational rate in x,y,z, so V0,R0, V1,R1,...Vn-1, Rn-1
       // allocate memory for polygon list
       if (!(explobj[eindex].ivar1 = (int)malloc(sizeof(VECTOR4D)*2*explobj[eindex].num_polys)))
          return(0);
       // clear data
       memset((void *)explobj[eindex].ivar1,0,sizeof(VECTOR4D)*2*explobj[eindex].num_polys);
       // alias working pointer
       VECTOR4D_PTR trajectory = (VECTOR4D_PTR)explobj[eindex].ivar1;
       // these are needed to track the "head" of the vertex list for multi-frame objects
       explobj[eindex].head_vlist_local = explobj[eindex].vlist_local;
       explobj[eindex].head_vlist_trans = explobj[eindex].vlist_trans;
       // set the lifetime in ivar2
       explobj[eindex].ivar2 = lifetime;
       // now comes the tricky part, loop and copy each polygon, but as we copy the polygons, we have to copy
       // the vertices, and insert them, and fix up the vertice indices etc.
       for (int pindex = 0; pindex < explobj[eindex].num_polys; pindex++)
           {
           // alright, we want to copy the (pindex*detail)th poly from the master to the (pindex)th
           // polygon in explosion
           explobj[eindex].plist[pindex] = obj->plist[pindex*detail];
           // we need to modify, the vertex list pointer and the vertex indices themselves
           explobj[eindex].plist[pindex].vlist = explobj[eindex].vlist_local;
           // now comes the hard part, we need to first copy the vertices from the original mesh
           // into the new vertex storage, but at the same time keep the same vertex ordering
          
           // vertex 0
           explobj[eindex].plist[pindex].vert[0] = pindex*3 + 0;
           explobj[eindex].vlist_local[pindex*3 + 0] = obj->vlist_local[ obj->plist[pindex*detail].vert[0] ];
           // vertex 1
           explobj[eindex].plist[pindex].vert[1] = pindex*3 + 1;
           explobj[eindex].vlist_local[pindex*3 + 1] = obj->vlist_local[ obj->plist[pindex*detail].vert[1] ];
           // vertex 2
           explobj[eindex].plist[pindex].vert[2] = pindex*3 + 2;
           explobj[eindex].vlist_local[pindex*3 + 2] = obj->vlist_local[ obj->plist[pindex*detail].vert[2] ];
           // reset shading flag to constant for some of the shrapnel since they are giving off light 
           if ((rand()%5) == 1)
              {
              SET_BIT(explobj[eindex].plist[pindex].attr, POLY4DV2_ATTR_SHADE_MODE_PURE);
              RESET_BIT(explobj[eindex].plist[pindex].attr, POLY4DV2_ATTR_SHADE_MODE_GOURAUD);
              RESET_BIT(explobj[eindex].plist[pindex].attr, POLY4DV2_ATTR_SHADE_MODE_FLAT);
              // set color
              explobj[eindex].plist[pindex].color = RGB16Bit(128+rand()%128,0,0);
              } // end if
           // add some random noise to trajectory
           static VECTOR4D mv;
       
           // first compute trajectory as vector from center to vertex piercing polygon
           VECTOR4D_INIT(&trajectory[pindex*2+0], &obj->vlist_local[ obj->plist[pindex*detail].vert[0] ].v);
           VECTOR4D_Scale(rate, &trajectory[pindex*2+0], &trajectory[pindex*2+0]);          
         
           mv.x = RAND_RANGE(-10,10);
           mv.y = RAND_RANGE(-10,10);
           mv.z = RAND_RANGE(-10,10);
           mv.w = 1;
           VECTOR4D_Add(&mv, &trajectory[pindex*2+0], &trajectory[pindex*2+0]);
           // now rotation rate, this is difficult to do since we don't have the center of the polygon
           // maybe later...
           // trajectory[pindex*2+1] = 
           } // end for pindex
       // now transform final mesh into position destructively
       Transform_OBJECT4DV2(&explobj[eindex], mrot, TRANSFORM_LOCAL_ONLY,1);
       return(1);
       
       } // end if found a free explosion
    } // end for eindex
// return failure
return(0);
} // end Start_Mesh_Explosion
///////////////////////////////////////////////////////////
void Process_Aliens(void)
{
// this function moves the aliens and performs AI
for (int index = 0; index < NUM_ALIENS; index++)
    {
    // which state is alien in
    switch(aliens[index].state)
          {
          // is the alien dead? if so move on
          case ALIEN_STATE_DEAD: break;
          // is the alien alive?
          case ALIEN_STATE_ALIVE:
          case ALIEN_STATE_DYING:
          {
          // move the alien
          aliens[index].pos.x+=aliens[index].vel.y;
          aliens[index].pos.y+=aliens[index].vel.y;
          aliens[index].pos.z+=aliens[index].vel.z;
        
          // rotate the alien
          if ((aliens[index].ang.x+=aliens[index].rot.x) > 360)
              aliens[index].ang.x = 0;
          if ((aliens[index].ang.y+=aliens[index].rot.y) > 360)
              aliens[index].ang.y = 0;
            
          if ((aliens[index].ang.z+=aliens[index].rot.z) > 360)
              aliens[index].ang.z = 0;
          // test if alien has past players near clipping plane
          // if so remove from simulation
          if (aliens[index].pos.z < cam.near_clip_z)
             {
             // remove from simulation
             aliens[index].state = ALIEN_STATE_DEAD;
             // another one gets away!
             escaped++;
             } // end if 
          } break;
   
      
          default: break;
          } // end switch
    } // end for index
} // end Process_Aliens
//////////////////////////////////////////////////////////
void Init_Starfield(void)
{
// create the starfield
for (int index=0; index < NUM_STARS; index++)
    {
    // randomly position stars in an elongated cylinder stretching from
    // the viewpoint 0,0,-d to the yon clipping plane 0,0,far_z
    stars[index].x = -WINDOW_WIDTH/2  + rand()%WINDOW_WIDTH;
    stars[index].y = -WINDOW_HEIGHT/2 + rand()%WINDOW_HEIGHT;
    stars[index].z = NEAR_Z + rand()%(FAR_Z - NEAR_Z);
    // set color of stars
    stars[index].color = rgb_white;
    } // end for index
} // end Init_Starfield
//////////////////////////////////////////////////////////
void Move_Starfield(void)
{
// move the stars
int index; // looping var
// the stars are technically stationary,but we are going
// to move them to simulate motion of the viewpoint
for (index=0; index<NUM_STARS; index++)
    {
    // move the next star
    stars[index].z-=(player_z_vel+3*diff_level);
    // test for past near clipping plane
    if (stars[index].z <= NEAR_Z)
        stars[index].z = FAR_Z;
    } // end for index
} // end Move_Starfield
/////////////////////////////////////////////////////////
void Draw_Starfield(UCHAR *video_buffer, int lpitch)
{
// draw the stars in 3D using perspective transform
int index; // looping var
// convert pitch to words
lpitch>>=1;
// draw each star
for (index=0; index < NUM_STARS; index++)
    {
    // draw the next star
    // step 1: perspective transform
    float x_per = VIEW_DISTANCE*stars[index].x/stars[index].z;
    float y_per = VIEW_DISTANCE*stars[index].y/stars[index].z;
    
    // step 2: compute screen coords
    int x_screen = WINDOW_WIDTH/2  + x_per;
    int y_screen = WINDOW_HEIGHT/2 - y_per;
    // clip to screen coords
    if (x_screen>=WINDOW_WIDTH || x_screen < 0 || 
        y_screen >= WINDOW_HEIGHT || y_screen < 0)
       {
       // continue to next star
       continue; 
       } // end if
    else
       {
       // else render to buffer
       int i = ((float)(10000*NEAR_Z) / stars[index].z);
       if (i > 255) i = 255;
       ((USHORT *)video_buffer)[x_screen + y_screen*lpitch] = RGB16Bit(i,i,i);
       } // end else
    } // end for index
}  // Draw_Starfield
/////////////////////////////////////////////////////////////
// T3D II GAME PROGRAMMING CONSOLE FUNCTIONS ////////////////
int Game_Init(void *parms)
{
// this function is where you do all the initialization 
// for your game
int index; // looping var
// start up DirectDraw (replace the parms as you desire)
DDraw_Init(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_BPP, WINDOWED_APP);
// initialize directinput
DInput_Init();
// acquire the keyboard and mouse
DInput_Init_Keyboard();
DInput_Init_Mouse();
// add calls to acquire other directinput devices here...
// initialize directsound and directmusic
DSound_Init();
DMusic_Init();
// load in sound fx
explosion_id       = DSound_Load_WAV("exp1.wav");
laser_id           = DSound_Load_WAV("shocker.wav");
game_over_id       = DSound_Load_WAV("gameover.wav");
ambient_systems_id = DSound_Load_WAV("stationthrob2.wav");
// initialize directmusic
DMusic_Init();
// load main music track
main_track_id = DMusic_Load_MIDI("midifile2.mid");
// hide the mouse
//if (!WINDOWED_APP)
    ShowCursor(FALSE);
// seed random number generator
srand(Start_Clock()); 
Open_Error_File("ERROR.TXT");
// initialize math engine
Build_Sin_Cos_Tables();
// initialize the camera with 90 FOV, normalized coordinates
Init_CAM4DV1(&cam,      // the camera object
             CAM_MODEL_EULER, // the euler model
             &cam_pos,  // initial camera position
             &cam_dir,  // initial camera angles
             &cam_target,    // no target
             150.0,          // near and far clipping planes
             20000.0,
             120.0,      // field of view in degrees
             WINDOW_WIDTH,   // size of final screen viewport
             WINDOW_HEIGHT);
// load flat shaded cube
VECTOR4D_INITXYZ(&vscale,18.00,18.00,18.00);
Load_OBJECT4DV2_COB(&obj_alien,"tie04.cob",  
                        &vscale, &vpos, &vrot, VERTEX_FLAGS_SWAP_YZ | VERTEX_FLAGS_SWAP_XZ |
                                               VERTEX_FLAGS_INVERT_WINDING_ORDER |
                                               VERTEX_FLAGS_TRANSFORM_LOCAL | 
                                               VERTEX_FLAGS_TRANSFORM_LOCAL_WORLD );
// create system colors
rgb_green = RGB16Bit(0,255,0);
rgb_white = RGB16Bit(255,255,255);
rgb_blue  = RGB16Bit(0,0,255);
rgb_red   = RGB16Bit(255,0,0);
// set up lights
Reset_Lights_LIGHTV1();
// create some working colors
white.rgba      = _RGBA32BIT(255,255,255,0);
light_gray.rgba = _RGBA32BIT(100,100,100,0);
gray.rgba       = _RGBA32BIT(50,50,50,0);
black.rgba      = _RGBA32BIT(0,0,0,0);
red.rgba        = _RGBA32BIT(255,0,0,0);
green.rgba      = _RGBA32BIT(0,255,0,0);
blue.rgba       = _RGBA32BIT(0,0,255,0);
// ambient light
Init_Light_LIGHTV1(AMBIENT_LIGHT_INDEX,   
                   LIGHTV1_STATE_ON,      // turn the light on
                   LIGHTV1_ATTR_AMBIENT,  // ambient light type
                   gray, black, black,    // color for ambient term only
                   NULL, NULL,            // no need for pos or dir
                   0,0,0,                 // no need for attenuation
                   0,0,0);                // spotlight info NA
VECTOR4D dlight_dir = {-1,-1,1,0};
// directional sun light
Init_Light_LIGHTV1(INFINITE_LIGHT_INDEX,  
                   LIGHTV1_STATE_ON,      // turn the light on
                   LIGHTV1_ATTR_INFINITE, // infinite light type
                   black, light_gray, black,    // color for diffuse term only
                   NULL, &dlight_dir,     // need direction only
                   0,0,0,                 // no need for attenuation
                   0,0,0);                // spotlight info NA
// the red giant
VECTOR4D plight_pos = {-2700,-1600,8000,0};
// point light
Init_Light_LIGHTV1(POINT_LIGHT_INDEX,
                   LIGHTV1_STATE_ON,      // turn the light on
                   LIGHTV1_ATTR_POINT,    // pointlight type
                   black, red, black,     // color for diffuse term only
                   &plight_pos, NULL,     // need pos only
                   0,.001,0,              // linear attenuation only
                   0,0,1);                // spotlight info NA
// the weapons blast green glow point light from front of ship
VECTOR4D plight2_pos = {0,0,200,0};
// point light2
Init_Light_LIGHTV1(POINT_LIGHT2_INDEX,
                   LIGHTV1_STATE_OFF,       // turn the light on
                   LIGHTV1_ATTR_POINT,     //  pointlight
                   black, green, black,      // color for diffuse term only
                   &plight2_pos, NULL, // need pos only
                   0,.0005,0,                 // linear attenuation only
                   0,0,1);    
// create lookup for lighting engine
RGB_16_8_IndexedRGB_Table_Builder(DD_PIXEL_FORMAT565,  // format we want to build table for
                                  palette,             // source palette
                                  rgblookup);          // lookup table
// load in the cockpit image
Load_Bitmap_File(&bitmap16bit, "cockpit03.BMP");
Create_BOB(&cockpit, 0,0,800,600,2, BOB_ATTR_VISIBLE | BOB_ATTR_SINGLE_FRAME, DDSCAPS_SYSTEMMEMORY, 0, 16); 
Load_Frame_BOB16(&cockpit, &bitmap16bit,0,0,0,BITMAP_EXTRACT_MODE_ABS);
Unload_Bitmap_File(&bitmap16bit);
Load_Bitmap_File(&bitmap16bit, "cockpit03b.BMP");
Load_Frame_BOB16(&cockpit, &bitmap16bit,1,0,0,BITMAP_EXTRACT_MODE_ABS);
Unload_Bitmap_File(&bitmap16bit);
// load in the background starscape
Load_Bitmap_File(&bitmap16bit, "nebgreen03.bmp");
Create_BOB(&starscape, 0,0,800,600,1, BOB_ATTR_VISIBLE | BOB_ATTR_SINGLE_FRAME, DDSCAPS_SYSTEMMEMORY, 0, 16); 
Load_Frame_BOB16(&starscape, &bitmap16bit,0,0,0,BITMAP_EXTRACT_MODE_ABS);
Unload_Bitmap_File(&bitmap16bit); 
// load the crosshair image
Load_Bitmap_File(&bitmap16bit, "crosshair01.bmp");
Create_BOB(&crosshair, 0,0,CROSS_WIDTH, CROSS_HEIGHT,1, BOB_ATTR_VISIBLE | BOB_ATTR_SINGLE_FRAME, DDSCAPS_SYSTEMMEMORY, 0, 16); 
Load_Frame_BOB16(&crosshair, &bitmap16bit,0,0,0,BITMAP_EXTRACT_MODE_ABS);
Unload_Bitmap_File(&bitmap16bit); 
return(1);
} // end Game_Init 
 
///////////////////////////////////////////////////////////
int Game_Shutdown(void *parms)
{
// this function is where you shutdown your game and
// release all resources that you allocated
// shut everything down
// release all your resources created for the game here....
// now directsound
DSound_Stop_All_Sounds();
DSound_Delete_All_Sounds();
DSound_Shutdown();
// directmusic
DMusic_Delete_All_MIDI();
DMusic_Shutdown();
// shut down directinput
DInput_Release_Keyboard();
// shutdown directinput
DInput_Shutdown();
// shutdown directdraw last
DDraw_Shutdown();
Close_Error_File();
// return success
return(1);
} // end Game_Shutdown
//////////////////////////////////////////////////////////
int Game_Main(void *parms)
{
// this is the workhorse of your game it will be called
// continuously in real-time this is like main() in C
// all the calls for you game go here!
static MATRIX4X4 mrot;   // general rotation matrix
// these are used to create a circling camera
static float view_angle = 0; 
static float camera_distance = 6000;
static VECTOR4D pos = {0,0,0,0};
static float tank_speed;
static float turning = 0;
// state variables for different rendering modes and help
static int wireframe_mode = 0;
static int backface_mode  = 1;
static int lighting_mode  = 1;
static int zsort_mode     = 1;
char work_string[256]; // temp string
int index; // looping var
// what state is game in?
switch(game_state)
      {
      case GAME_STATE_INIT:
      {
      // load the font
      Load_Bitmap_Font("tech_char_set_01.bmp", &tech_font);
     
      // transition to un state
      game_state = GAME_STATE_RESTART;
      } break;
      case GAME_STATE_RESTART:
      {
      // start music
      DMusic_Play(main_track_id);
      DSound_Play(ambient_systems_id, DSBPLAY_LOOPING);
      // initialize the stars
      Init_Starfield();      
      // initialize all the aliens
      Init_Aliens();
      // reset all vars
      player_z_vel = 4; // virtual speed of viewpoint/ship
      cross_x = CROSS_START_X; // cross hairs
      cross_y = CROSS_START_Y;
      cross_x_screen  = CROSS_START_X;   // used for cross hair
      cross_y_screen  = CROSS_START_Y; 
      target_x_screen = CROSS_START_X;   // used for targeter
      target_y_screen = CROSS_START_Y;
      escaped       = 0;   // tracks number of missed ships
      hits          = 0;   // tracks number of hits
      score         = 0;   // take a guess :)
      weapon_energy = 100; // weapon energy
      weapon_active = 0;   // weapons are off
      
      game_state_count1    = 0;    // general counters
      game_state_count2    = 0;
      restart_state        = 0;    // state when game is restarting
      restart_state_count1 = 0;    // general counter
      // difficulty
      diff_level           = 1;
      // transition to run state
      game_state = GAME_STATE_RUN;
      } break;
      case GAME_STATE_RUN:
      case GAME_STATE_OVER: // keep running sim, but kill diff_level, and player input
      {
      // start the clock
      Start_Clock();
      // clear the drawing surface 
      //DDraw_Fill_Surface(lpddsback, 0);
      // blt to destination surface
      lpddsback->Blt(NULL, starscape.images[starscape.curr_frame], NULL, DDBLT_WAIT, NULL); 
      // reset the render list
      Reset_RENDERLIST4DV2(&rend_list);
      // read keyboard and other devices here
      DInput_Read_Keyboard();
      DInput_Read_Mouse();
      // game logic begins here...
#ifdef DEBUG_ON      
      if (keyboard_state[DIK_UP])
         {
         py+=10;        
         } // end if
 
      if (keyboard_state[DIK_DOWN])
         {
         py-=10;     
         } // end if
      if (keyboard_state[DIK_RIGHT])
         {
         px+=10;
         } // end if
      if (keyboard_state[DIK_LEFT])
         {
         px-=10;
         } // end if
      if (keyboard_state[DIK_1])
         {
         pz+=20;
         } // end if
      if (keyboard_state[DIK_2])
         {
         pz-=20;
         } // end if
#endif
      // modes and lights
      // wireframe mode
      if (keyboard_state[DIK_W])
        {
        // toggle wireframe mode
        if (++wireframe_mode > 1)
           wireframe_mode = 0;
           Wait_Clock(100); // wait, so keyboard doesn't bounce
        } // end if
     // backface removal
     if (keyboard_state[DIK_B])
        {
        // toggle backface removal
        backface_mode = -backface_mode;
        Wait_Clock(100); // wait, so keyboard doesn't bounce
        } // end if
     // lighting
     if (keyboard_state[DIK_L])
        {
        // toggle lighting engine completely
        lighting_mode = -lighting_mode;
        Wait_Clock(100); // wait, so keyboard doesn't bounce
        } // end if
     // toggle ambient light
     if (keyboard_state[DIK_A])
        {
        // toggle ambient light
        if (lights[AMBIENT_LIGHT_INDEX].state == LIGHTV1_STATE_ON)
           lights[AMBIENT_LIGHT_INDEX].state = LIGHTV1_STATE_OFF;
        else
           lights[AMBIENT_LIGHT_INDEX].state = LIGHTV1_STATE_ON;
        Wait_Clock(100); // wait, so keyboard doesn't bounce
        } // end if
      // toggle infinite light
      if (keyboard_state[DIK_I])
         {
         // toggle ambient light
         if (lights[INFINITE_LIGHT_INDEX].state == LIGHTV1_STATE_ON)
            lights[INFINITE_LIGHT_INDEX].state = LIGHTV1_STATE_OFF;
         else
            lights[INFINITE_LIGHT_INDEX].state = LIGHTV1_STATE_ON;
         Wait_Clock(100); // wait, so keyboard doesn't bounce
          } // end if
      // toggle point light
      if (keyboard_state[DIK_P])
         {
         // toggle point light
         if (lights[POINT_LIGHT_INDEX].state == LIGHTV1_STATE_ON)
            lights[POINT_LIGHT_INDEX].state = LIGHTV1_STATE_OFF;
        else
            lights[POINT_LIGHT_INDEX].state = LIGHTV1_STATE_ON;
         Wait_Clock(100); // wait, so keyboard doesn't bounce
         } // end if
       // toggle spot light
       if (keyboard_state[DIK_S])
          {
          // toggle spot light
          if (lights[SPOT_LIGHT2_INDEX].state == LIGHTV1_STATE_ON)
             lights[SPOT_LIGHT2_INDEX].state = LIGHTV1_STATE_OFF;
          else
             lights[SPOT_LIGHT2_INDEX].state = LIGHTV1_STATE_ON;
          Wait_Clock(100); // wait, so keyboard doesn't bounce
          } // end if
       // z-sorting
       if (keyboard_state[DIK_Z])
          {
          // toggle z sorting
          zsort_mode = -zsort_mode;
          Wait_Clock(100); // wait, so keyboard doesn't bounce
          } // end if
       // track cross hair
       cross_x+=(mouse_state.lX);
       cross_y-=(mouse_state.lY); 
       // check bounds (x,y) are in 2D space coords, not screen coords
       if (cross_x >= (WINDOW_WIDTH/2-CROSS_WIDTH/2))
           cross_x = (WINDOW_WIDTH/2-CROSS_WIDTH/2) - 1;
       else
       if (cross_x <= -(WINDOW_WIDTH/2-CROSS_WIDTH/2))
           cross_x = -(WINDOW_WIDTH/2-CROSS_WIDTH/2) + 1;
       if (cross_y >= (WINDOW_HEIGHT/2-CROSS_HEIGHT/2))
           cross_y = (WINDOW_HEIGHT/2-CROSS_HEIGHT/2) - 1;
       else
       if (cross_y <= -(WINDOW_HEIGHT/2-CROSS_HEIGHT/2))
           cross_y = -(WINDOW_HEIGHT/2-CROSS_HEIGHT/2) + 1;
       // player is done moving create camera matrix //////////////////////////
       Build_CAM4DV1_Matrix_Euler(&cam, CAM_ROT_SEQ_ZYX);
       // perform all non-player game AI and motion here /////////////////////
       // move starfield
       Move_Starfield();
       // move aliens
       Process_Aliens(); 
       // update difficulty of game
       if ((diff_level+=DIFF_RATE) > DIFF_PMAX)
           diff_level = DIFF_PMAX;
       // start a random alien as a function of game difficulty
       if ( (rand()%(DIFF_PMAX - (int)diff_level+2)) == 1)
          Start_Alien();
       
       // perform animation and transforms on lights //////////////////////////
       // lock the back buffer
       DDraw_Lock_Back_Surface();
       // draw all 3D entities
       Draw_Aliens();
       // draw mesh explosions
       Draw_Mesh_Explosions();
    
       // entire into final 3D pipeline /////////////////////////////////////// 
   
       // remove backfaces
       if (backface_mode==1)
          Remove_Backfaces_RENDERLIST4DV2(&rend_list, &cam);
       // light scene all at once 
       if (lighting_mode==1)
          Light_RENDERLIST4DV2_World16(&rend_list, &cam, lights, 4);
       // apply world to camera transform
       World_To_Camera_RENDERLIST4DV2(&rend_list, &cam);
       // sort the polygon list (hurry up!)
       if (zsort_mode == 1)
          Sort_RENDERLIST4DV2(&rend_list,  SORT_POLYLIST_AVGZ);
       // apply camera to perspective transformation
       Camera_To_Perspective_RENDERLIST4DV2(&rend_list, &cam);
       // apply screen transform
       Perspective_To_Screen_RENDERLIST4DV2(&rend_list, &cam);
       // draw the starfield now
       Draw_Starfield(back_buffer, back_lpitch);
       // reset number of polys rendered
       debug_polys_rendered_per_frame = 0;
       // render the list
       if (wireframe_mode  == 0)
          {
          Draw_RENDERLIST4DV2_Solid16(&rend_list, back_buffer, back_lpitch);
          }
       else
       if (wireframe_mode  == 1)
          {
          Draw_RENDERLIST4DV2_Wire16(&rend_list, back_buffer, back_lpitch);
          } // end if
       // draw energy bindings
       Render_Energy_Bindings(energy_bindings, 1, 8, 16, RGB16Bit(0,255,0), back_buffer, back_lpitch);
       // fire the weapon
       if (game_state == GAME_STATE_RUN && mouse_state.rgbButtons[0] && weapon_energy > 20)
          {
          // set endpoints of energy bolts
          weapon_bursts[1].x = cross_x_screen + RAND_RANGE(-4,4);
          weapon_bursts[1].y = cross_y_screen + RAND_RANGE(-4,4);
          weapon_bursts[3].x = cross_x_screen + RAND_RANGE(-4,4);
          weapon_bursts[3].y = cross_y_screen + RAND_RANGE(-4,4);
          // draw the weapons firing
          Render_Weapon_Bursts(weapon_bursts, 2, 8, 16, RGB16Bit(0,255,0), back_buffer, back_lpitch);
          // decrease weapon energy
          if ((weapon_energy-=5) < 0)
             weapon_energy = 0;
          // make sound
          DSound_Play(laser_id);
          // energize weapons
          weapon_active  = 1; 
          // turn the lights on!
          lights[POINT_LIGHT2_INDEX].state = LIGHTV1_STATE_ON;
          cockpit.curr_frame = 1;
          } // end if
        else
           {
           weapon_active  = 0; 
           // turn the lights off!
           lights[POINT_LIGHT2_INDEX].state = LIGHTV1_STATE_OFF;
           cockpit.curr_frame = 0;
           } // end else
          if ((weapon_energy+=1) > 100)
             weapon_energy = 100;
       // draw any overlays ///////////////////////////////////////////////////
       // unlock the back buffer
       DDraw_Unlock_Back_Surface();
       // draw cockpit
       Draw_BOB16(&cockpit, lpddsback);
       // draw information
       sprintf(work_string, "SCORE:%d", score);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_SCORE_X,TPOS_SCORE_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       sprintf(work_string, "HITS:%d", hits);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_HITS_X,TPOS_HITS_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       sprintf(work_string, "ESCAPED:%d", escaped);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_ESCAPED_X,TPOS_ESCAPED_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       sprintf(work_string, "LEVEL:%2.4f", diff_level);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_GLEVEL_X,TPOS_GLEVEL_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       sprintf(work_string, "VEL:%3.2fK/S", player_z_vel+diff_level);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_SPEED_X,TPOS_SPEED_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       sprintf(work_string, "NRG:%d", weapon_energy);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_ENERGY_X,TPOS_ENERGY_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
       
       // process game over stuff
       if (game_state == GAME_STATE_OVER)
          {
          // do rendering
          sprintf(work_string, "GAME OVER");  
          Draw_Bitmap_Font_String(&tech_font, TPOS_GINFO_X-(FONT_HPITCH/2)*strlen(work_string),TPOS_GINFO_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
 
          sprintf(work_string, "PRESS ENTER TO PLAY AGAIN");  
          Draw_Bitmap_Font_String(&tech_font, TPOS_GINFO_X-(FONT_HPITCH/2)*strlen(work_string),TPOS_GINFO_Y + 2*FONT_VPITCH, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
          // logic...
          if (keyboard_state[DIK_RETURN])
             {
             game_state = GAME_STATE_RESTART;
             } // end if
          } // end if
#ifdef DEBUG_ON
       // display diagnostics
       sprintf(work_string,"LE[%s]:AMB=%d,INFL=%d,PNTL=%d,SPTL=%d,ZS[%s],BFRM[%s], WF=%s", 
                                                                                 ((lighting_mode == 1) ? "ON" : "OFF"),
                                                                                 lights[AMBIENT_LIGHT_INDEX].state,
                                                                                 lights[INFINITE_LIGHT_INDEX].state, 
                                                                                 lights[POINT_LIGHT_INDEX].state,
                                                                                 lights[SPOT_LIGHT2_INDEX].state,
                                                                                 ((zsort_mode == 1) ? "ON" : "OFF"),
                                                                                 ((backface_mode == 1) ? "ON" : "OFF"),
                                                                                 ((wireframe_mode == 1) ? "ON" : "OFF"));
       Draw_Bitmap_Font_String(&tech_font, 4,WINDOW_HEIGHT-16, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
#endif
       // draw startup information for first few seconds of restart
       if (restart_state == 0)
          {
          sprintf(work_string, "GET READY!");  
          Draw_Bitmap_Font_String(&tech_font, TPOS_GINFO_X-(FONT_HPITCH/2)*strlen(work_string),TPOS_GINFO_Y, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
          // update counter
          if (++restart_state_count1 > 100)
             restart_state = 1; 
          } // end if
 
#ifdef DEBUG_ON
       sprintf(work_string, "p=[%d, %d, %d]", px,py,pz);  
       Draw_Bitmap_Font_String(&tech_font, TPOS_GINFO_X-(FONT_HPITCH/2)*strlen(work_string),TPOS_GINFO_Y+24, work_string, FONT_HPITCH, FONT_VPITCH, lpddsback);
#endif
       if (game_state == GAME_STATE_RUN)
       {
       // draw cross on top of everything, it's holographic :)
       cross_x_screen = WINDOW_WIDTH/2  + cross_x;
       cross_y_screen = WINDOW_HEIGHT/2 - cross_y;
     
       crosshair.x = cross_x_screen - CROSS_WIDTH/2+1;
       crosshair.y = cross_y_screen - CROSS_HEIGHT/2;
       Draw_BOB16(&crosshair, lpddsback);
       } // end if
       // flip the surfaces
       DDraw_Flip();
       // sync to 30ish fps
       Wait_Clock(30);
       // check if player has lost?
       if (escaped == MAX_MISSES_GAME_OVER)
          {
          game_state = GAME_STATE_OVER;
          DSound_Play(game_over_id);
          escaped++;
          } // end if
       // check of user is trying to exit
       if (KEY_DOWN(VK_ESCAPE) || keyboard_state[DIK_ESCAPE])
          {
          PostMessage(main_window_handle, WM_DESTROY,0,0);
          game_state = GAME_STATE_EXIT;
          } // end if      
      } break;
      case GAME_STATE_DEMO:
      {
      } break;
      case GAME_STATE_EXIT:
      {
      } break;
      default: break;
      } // end switch game state
// return success
return(1);
 
} // end Game_Main
//////////////////////////////////////////////////////////

						