STEAM.C
上传用户:tengyuc
上传日期:2007-08-14
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文件大小:15k
- /**
- Description: Interactive 3D graphics, Assignment #1
- Miniature Steam Engine Simulation.
- Author: Troy Robinette
- Date: 29/9/95
- Email: troyr@yallara.cs.rmit.edu.au
- Notes: - Transparence doesn't quite work. The color of the
- underlying object doesn't show through.
- - Also only the front side of the transparent objects are
- transparent.
- **/
- #include <stdio.h>
- #include <GL/glut.h>
- #include <math.h>
- #define TRUE 1
- #define FALSE 0
- /* Dimensions of texture image. */
- #define IMAGE_WIDTH 64
- #define IMAGE_HEIGHT 64
- /* Step to be taken for each rotation. */
- #define ANGLE_STEP 10
- /* Magic numbers for relationship b/w cylinder head and crankshaft. */
- #define MAGNITUDE 120
- #define PHASE 270.112
- #define FREQ_DIV 58
- #define ARC_LENGHT 2.7
- #define ARC_RADIUS 0.15
- /* Rotation angles */
- GLdouble view_h = 270, view_v = 0, head_angle = 0;
- GLint crank_angle = 0;
- /* Crank rotation step. */
- GLdouble crank_step = 5;
- /* Toggles */
- GLshort shaded = TRUE, anim = FALSE;
- GLshort texture = FALSE, transparent = FALSE;
- GLshort light1 = TRUE, light2 = FALSE;
- /* Storage for the angle look up table and the texture map */
- GLdouble head_look_up_table[361];
- GLubyte image[IMAGE_WIDTH][IMAGE_HEIGHT][3];
- /* Indentifiers for each Display list */
- GLint list_piston_shaded = 1;
- GLint list_piston_texture = 2;
- GLint list_flywheel_shaded = 4;
- GLint list_flywheel_texture = 8;
- /* Variable used in the creaton of glu objects */
- GLUquadricObj *obj;
- /* Draws a box by scaling a glut cube of size 1. Also checks the shaded
- toggle to see which rendering style to use. NB Texture doesn't work
- correctly due to the cube being scaled. */
- void
- myBox(GLdouble x, GLdouble y, GLdouble z)
- {
- glPushMatrix();
- glScalef(x, y, z);
- if (shaded)
- glutSolidCube(1);
- else
- glutWireCube(1);
- glPopMatrix();
- }
- /* Draws a cylinder using glu function, drawing flat disc's at each end,
- to give the appearence of it being solid. */
- void
- myCylinder(GLUquadricObj * object, GLdouble outerRadius,
- GLdouble innerRadius, GLdouble lenght)
- {
- glPushMatrix();
- gluCylinder(object, outerRadius, outerRadius, lenght, 20, 1);
- glPushMatrix();
- glRotatef(180, 0.0, 1.0, 0.0);
- gluDisk(object, innerRadius, outerRadius, 20, 1);
- glPopMatrix();
- glTranslatef(0.0, 0.0, lenght);
- gluDisk(object, innerRadius, outerRadius, 20, 1);
- glPopMatrix();
- }
- /* Draws a piston. */
- void
- draw_piston(void)
- {
- glPushMatrix();
- glColor4f(0.3, 0.6, 0.9, 1.0);
- glPushMatrix();
- glRotatef(90, 0.0, 1.0, 0.0);
- glTranslatef(0.0, 0.0, -0.07);
- myCylinder(obj, 0.125, 0.06, 0.12);
- glPopMatrix();
- glRotatef(-90, 1.0, 0.0, 0.0);
- glTranslatef(0.0, 0.0, 0.05);
- myCylinder(obj, 0.06, 0.0, 0.6);
- glTranslatef(0.0, 0.0, 0.6);
- myCylinder(obj, 0.2, 0.0, 0.5);
- glPopMatrix();
- }
- /* Draws the engine pole and the pivot pole for the cylinder head. */
- void
- draw_engine_pole(void)
- {
- glPushMatrix();
- glColor4f(0.9, 0.9, 0.9, 1.0);
- myBox(0.5, 3.0, 0.5);
- glColor3f(0.5, 0.1, 0.5);
- glRotatef(90, 0.0, 1.0, 0.0);
- glTranslatef(0.0, 0.9, -0.4);
- myCylinder(obj, 0.1, 0.0, 2);
- glPopMatrix();
- }
- /* Draws the cylinder head at the appropreate angle, doing the necesary
- translations for the rotation. */
- void
- draw_cylinder_head(void)
- {
- glPushMatrix();
- glColor4f(0.5, 1.0, 0.5, 0.1);
- glRotatef(90, 1.0, 0.0, 0.0);
- glTranslatef(0, 0.0, 0.4);
- glRotatef(head_angle, 1, 0, 0);
- glTranslatef(0, 0.0, -0.4);
- myCylinder(obj, 0.23, 0.21, 1.6);
- glRotatef(180, 1.0, 0.0, 0.0);
- gluDisk(obj, 0, 0.23, 20, 1);
- glPopMatrix();
- }
- /* Draws the flywheel. */
- void
- draw_flywheel(void)
- {
- glPushMatrix();
- glColor4f(0.5, 0.5, 1.0, 1.0);
- glRotatef(90, 0.0, 1.0, 0.0);
- myCylinder(obj, 0.625, 0.08, 0.5);
- glPopMatrix();
- }
- /* Draws the crank bell, and the pivot pin for the piston. Also calls the
- appropreate display list of a piston doing the nesacary rotations before
- hand. */
- void
- draw_crankbell(void)
- {
- glPushMatrix();
- glColor4f(1.0, 0.5, 0.5, 1.0);
- glRotatef(90, 0.0, 1.0, 0.0);
- myCylinder(obj, 0.3, 0.08, 0.12);
- glColor4f(0.5, 0.1, 0.5, 1.0);
- glTranslatef(0.0, 0.2, 0.0);
- myCylinder(obj, 0.06, 0.0, 0.34);
- glTranslatef(0.0, 0.0, 0.22);
- glRotatef(90, 0.0, 1.0, 0.0);
- glRotatef(crank_angle - head_angle, 1.0, 0.0, 0.0);
- if (shaded) {
- if (texture)
- glCallList(list_piston_texture);
- else
- glCallList(list_piston_shaded);
- } else
- draw_piston();
- glPopMatrix();
- }
- /* Draws the complete crank. Piston also gets drawn through the crank bell
- function. */
- void
- draw_crank(void)
- {
- glPushMatrix();
- glRotatef(crank_angle, 1.0, 0.0, 0.0);
- glPushMatrix();
- glRotatef(90, 0.0, 1.0, 0.0);
- glTranslatef(0.0, 0.0, -1.0);
- myCylinder(obj, 0.08, 0.0, 1.4);
- glPopMatrix();
- glPushMatrix();
- glTranslatef(0.28, 0.0, 0.0);
- draw_crankbell();
- glPopMatrix();
- glPushMatrix();
- glTranslatef(-0.77, 0.0, 0.0);
- if (shaded) {
- if (texture)
- glCallList(list_flywheel_texture);
- else
- glCallList(list_flywheel_shaded);
- } else
- draw_flywheel();
- glPopMatrix();
- glPopMatrix();
- }
- /* Main display routine. Clears the drawing buffer and if transparency is
- set, displays the model twice, 1st time accepting those fragments with
- a ALPHA value of 1 only, then with DEPTH_BUFFER writing disabled for
- those with other values. */
- void
- display(void)
- {
- int pass;
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
- glPushMatrix();
- if (transparent) {
- glEnable(GL_ALPHA_TEST);
- pass = 2;
- } else {
- glDisable(GL_ALPHA_TEST);
- pass = 0;
- }
- /* Rotate the whole model */
- glRotatef(view_h, 0, 1, 0);
- glRotatef(view_v, 1, 0, 0);
- do {
- if (pass == 2) {
- glAlphaFunc(GL_EQUAL, 1);
- glDepthMask(GL_TRUE);
- pass--;
- } else if (pass != 0) {
- glAlphaFunc(GL_NOTEQUAL, 1);
- glDepthMask(GL_FALSE);
- pass--;
- }
- draw_engine_pole();
- glPushMatrix();
- glTranslatef(0.5, 1.4, 0.0);
- draw_cylinder_head();
- glPopMatrix();
- glPushMatrix();
- glTranslatef(0.0, -0.8, 0.0);
- draw_crank();
- glPopMatrix();
- } while (pass > 0);
- glDepthMask(GL_TRUE);
- glutSwapBuffers();
- glPopMatrix();
- }
- /* Called when the window is idle. When called increments the crank angle
- by ANGLE_STEP, updates the head angle and notifies the system that
- the screen needs to be updated. */
- void
- animation(void)
- {
- if ((crank_angle += crank_step) >= 360)
- crank_angle = 0;
- head_angle = head_look_up_table[crank_angle];
- glutPostRedisplay();
- }
- /* Called when a key is pressed. Checks if it reconises the key and if so
- acts on it, updateing the screen. */
- /* ARGSUSED1 */
- void
- keyboard(unsigned char key, int x, int y)
- {
- switch (key) {
- case 's':
- if (shaded == FALSE) {
- shaded = TRUE;
- glShadeModel(GL_SMOOTH);
- glEnable(GL_LIGHTING);
- glEnable(GL_DEPTH_TEST);
- glEnable(GL_COLOR_MATERIAL);
- gluQuadricNormals(obj, GLU_SMOOTH);
- gluQuadricDrawStyle(obj, GLU_FILL);
- } else {
- shaded = FALSE;
- glShadeModel(GL_FLAT);
- glDisable(GL_LIGHTING);
- glDisable(GL_DEPTH_TEST);
- glDisable(GL_COLOR_MATERIAL);
- gluQuadricNormals(obj, GLU_NONE);
- gluQuadricDrawStyle(obj, GLU_LINE);
- gluQuadricTexture(obj, GL_FALSE);
- }
- if (texture && !shaded);
- else
- break;
- case 't':
- if (texture == FALSE) {
- texture = TRUE;
- glEnable(GL_TEXTURE_2D);
- gluQuadricTexture(obj, GL_TRUE);
- } else {
- texture = FALSE;
- glDisable(GL_TEXTURE_2D);
- gluQuadricTexture(obj, GL_FALSE);
- }
- break;
- case 'o':
- if (transparent == FALSE) {
- transparent = TRUE;
- } else {
- transparent = FALSE;
- }
- break;
- case 'a':
- if ((crank_angle += crank_step) >= 360)
- crank_angle = 0;
- head_angle = head_look_up_table[crank_angle];
- break;
- case 'z':
- if ((crank_angle -= crank_step) <= 0)
- crank_angle = 360;
- head_angle = head_look_up_table[crank_angle];
- break;
- case '0':
- if (light1) {
- glDisable(GL_LIGHT0);
- light1 = FALSE;
- } else {
- glEnable(GL_LIGHT0);
- light1 = TRUE;
- }
- break;
- case '1':
- if (light2) {
- glDisable(GL_LIGHT1);
- light2 = FALSE;
- } else {
- glEnable(GL_LIGHT1);
- light2 = TRUE;
- }
- break;
- case '4':
- if ((view_h -= ANGLE_STEP) <= 0)
- view_h = 360;
- break;
- case '6':
- if ((view_h += ANGLE_STEP) >= 360)
- view_h = 0;
- break;
- case '8':
- if ((view_v += ANGLE_STEP) >= 360)
- view_v = 0;
- break;
- case '2':
- if ((view_v -= ANGLE_STEP) <= 0)
- view_v = 360;
- break;
- case ' ':
- if (anim) {
- glutIdleFunc(0);
- anim = FALSE;
- } else {
- glutIdleFunc(animation);
- anim = TRUE;
- }
- break;
- case '+':
- if ((++crank_step) > 45)
- crank_step = 45;
- break;
- case '-':
- if ((--crank_step) <= 0)
- crank_step = 0;
- break;
- default:
- return;
- }
- glutPostRedisplay();
- }
- /* ARGSUSED1 */
- void
- special(int key, int x, int y)
- {
- switch (key) {
- case GLUT_KEY_LEFT:
- if ((view_h -= ANGLE_STEP) <= 0)
- view_h = 360;
- break;
- case GLUT_KEY_RIGHT:
- if ((view_h += ANGLE_STEP) >= 360)
- view_h = 0;
- break;
- case GLUT_KEY_UP:
- if ((view_v += ANGLE_STEP) >= 360)
- view_v = 0;
- break;
- case GLUT_KEY_DOWN:
- if ((view_v -= ANGLE_STEP) <= 0)
- view_v = 360;
- break;
- default:
- return;
- }
- glutPostRedisplay();
- }
- /* Called when a menu option has been selected. Translates the menu item
- identifier into a keystroke, then call's the keyboard function. */
- void
- menu(int val)
- {
- unsigned char key;
- switch (val) {
- case 1:
- key = 's';
- break;
- case 2:
- key = ' ';
- break;
- case 3:
- key = 't';
- break;
- case 4:
- key = 'o';
- break;
- case 5:
- key = '0';
- break;
- case 6:
- key = '1';
- break;
- case 7:
- key = '+';
- break;
- case 8:
- key = '-';
- break;
- default:
- return;
- }
- keyboard(key, 0, 0);
- }
- /* Initialises the menu of toggles. */
- void
- create_menu(void)
- {
- glutCreateMenu(menu);
- glutAttachMenu(GLUT_LEFT_BUTTON);
- glutAttachMenu(GLUT_RIGHT_BUTTON);
- glutAddMenuEntry("Shaded", 1);
- glutAddMenuEntry("Animation", 2);
- glutAddMenuEntry("Texture", 3);
- glutAddMenuEntry("Transparency", 4);
- glutAddMenuEntry("Right Light (0)", 5);
- glutAddMenuEntry("Left Light (1)", 6);
- glutAddMenuEntry("Speed UP", 7);
- glutAddMenuEntry("Slow Down", 8);
- }
- /* Makes a simple check pattern image. (Copied from the redbook example
- "checker.c".) */
- void
- make_image(void)
- {
- int i, j, c;
- for (i = 0; i < IMAGE_WIDTH; i++) {
- for (j = 0; j < IMAGE_HEIGHT; j++) {
- c = ((((i & 0x8) == 0) ^ ((j & 0x8)) == 0)) * 255;
- image[i][j][0] = (GLubyte) c;
- image[i][j][1] = (GLubyte) c;
- image[i][j][2] = (GLubyte) c;
- }
- }
- }
- /* Makes the head look up table for all possible crank angles. */
- void
- make_table(void)
- {
- GLint i;
- GLdouble k;
- for (i = 0, k = 0.0; i < 360; i++, k++) {
- head_look_up_table[i] =
- MAGNITUDE * atan(
- (ARC_RADIUS * sin(PHASE - k / FREQ_DIV)) /
- ((ARC_LENGHT - ARC_RADIUS * cos(PHASE - k / FREQ_DIV))));
- }
- }
- /* Initialises texturing, lighting, display lists, and everything else
- associated with the model. */
- void
- myinit(void)
- {
- GLfloat mat_specular[] = {1.0, 1.0, 1.0, 1.0};
- GLfloat mat_shininess[] = {50.0};
- GLfloat light_position1[] = {1.0, 1.0, 1.0, 0.0};
- GLfloat light_position2[] = {-1.0, 1.0, 1.0, 0.0};
- glClearColor(0.0, 0.0, 0.0, 0.0);
- obj = gluNewQuadric();
- make_table();
- make_image();
- /* Set up Texturing */
- glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
- glTexImage2D(GL_TEXTURE_2D, 0, 3, IMAGE_WIDTH,
- IMAGE_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE,
- image);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
- glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
- /* Set up Lighting */
- glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
- glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
- glLightfv(GL_LIGHT0, GL_POSITION, light_position1);
- glLightfv(GL_LIGHT1, GL_POSITION, light_position2);
- /* Initial render mode is with full shading and LIGHT 0
- enabled. */
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT0);
- glDepthFunc(GL_LEQUAL);
- glEnable(GL_DEPTH_TEST);
- glDisable(GL_ALPHA_TEST);
- glColorMaterial(GL_FRONT_AND_BACK, GL_DIFFUSE);
- glEnable(GL_COLOR_MATERIAL);
- glShadeModel(GL_SMOOTH);
- /* Initialise display lists */
- glNewList(list_piston_shaded, GL_COMPILE);
- draw_piston();
- glEndList();
- glNewList(list_flywheel_shaded, GL_COMPILE);
- draw_flywheel();
- glEndList();
- gluQuadricTexture(obj, GL_TRUE);
- glNewList(list_piston_texture, GL_COMPILE);
- draw_piston();
- glEndList();
- glNewList(list_flywheel_texture, GL_COMPILE);
- draw_flywheel();
- glEndList();
- gluQuadricTexture(obj, GL_FALSE);
- }
- /* Called when the model's window has been reshaped. */
- void
- myReshape(int w, int h)
- {
- glViewport(0, 0, w, h);
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- gluPerspective(65.0, (GLfloat) w / (GLfloat) h, 1.0, 20.0);
- glMatrixMode(GL_MODELVIEW);
- glLoadIdentity();
- glTranslatef(0.0, 0.0, -5.0); /* viewing transform */
- glScalef(1.5, 1.5, 1.5);
- }
- /* Main program. An interactive model of a miniture steam engine.
- Sets system in Double Buffered mode and initialises all the call-back
- functions. */
- int
- main(int argc, char **argv)
- {
- puts("Miniature Steam Engine Troy Robinetten");
- puts("Keypad Arrow keys (with NUM_LOCK on) rotates object.");
- puts("Rotate crank: 'a' = anti-clock wise 'z' = clock wise");
- puts("Crank Speed : '+' = Speed up by 1 '-' = Slow Down by 1");
- puts("Toggle : 's' = Shading 't' = Texture");
- puts(" : ' ' = Animation 'o' = Transparency");
- puts(" : '0' = Right Light '1' = Left Light");
- puts(" Alternatively a pop up menu with all toggles is attached");
- puts(" to the left mouse button.n");
- glutInitWindowSize(400, 400);
- glutInit(&argc, argv);
- /* Transperancy won't work properly without GLUT_ALPHA */
- glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_MULTISAMPLE);
- glutCreateWindow("Miniature Steam Engine by Troy Robinette");
- glutDisplayFunc(display);
- glutKeyboardFunc(keyboard);
- glutSpecialFunc(special);
- create_menu();
- myinit();
- glutReshapeFunc(myReshape);
- glutMainLoop();
- return 0; /* ANSI C requires main to return int. */
- }