Billboard.cpp
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上传日期:2009-05-26
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文件大小:3k
- /*
- s_p_oneil@hotmail.com
- Copyright (c) 2000, Sean O'Neil
- All rights reserved.
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are met:
- * Redistributions of source code must retain the above copyright notice,
- this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above copyright notice,
- this list of conditions and the following disclaimer in the documentation
- and/or other materials provided with the distribution.
- * Neither the name of this project nor the names of its contributors
- may be used to endorse or promote products derived from this software
- without specific prior written permission.
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- POSSIBILITY OF SUCH DAMAGE.
- */
- #include "Master.h"
- #include "Billboard.h"
- void CBillboard::Draw(CTexture *pTexture, CVector vPos, float fSize)
- {
- pTexture->Enable();
- glBegin(GL_QUADS);
- glTexCoord2f(0, 0);
- glVertex3f(vPos.x-fSize, vPos.y+fSize, vPos.z);
- glTexCoord2f(0, 1);
- glVertex3f(vPos.x-fSize, vPos.y-fSize, vPos.z);
- glTexCoord2f(1, 1);
- glVertex3f(vPos.x+fSize, vPos.y-fSize, vPos.z);
- glTexCoord2f(1, 0);
- glVertex3f(vPos.x+fSize, vPos.y+fSize, vPos.z);
- glEnd();
- pTexture->Disable();
- }
- void CBillboard::Draw(CTexture *pTexture, C3DObject *pCamera, CVector vPos, CVector vUp, float fSize)
- {
- // First determine the actual normal, up, and right vectors for the billboard
- vPos -= pCamera->GetPosition();
- float fDistance = vPos.Magnitude();
- CVector vNormal = vPos / -fDistance;
- CVector vRight = vUp ^ vNormal;
- vRight.Normalize();
- vUp = vNormal ^ vRight;
- vUp.Normalize();
- float fScale = C3DObject::GetScalingFactor(fDistance);
- vPos *= fScale;
- vRight *= fScale;
- vUp *= fScale;
- // Then draw the billboarded rectangle
- pTexture->Enable();
- glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
- glEnable(GL_BLEND);
- glBegin(GL_QUADS);
- glTexCoord2f(0, 1);
- glVertex3fv(vPos + vUp*fSize + vRight*(-fSize));
- glTexCoord2f(0, 0);
- glVertex3fv(vPos + vUp*(-fSize) + vRight*(-fSize));
- glTexCoord2f(1, 0);
- glVertex3fv(vPos + vUp*(-fSize) + vRight*fSize);
- glTexCoord2f(1, 1);
- glVertex3fv(vPos + vUp*fSize + vRight*fSize);
- glEnd();
- glDisable(GL_BLEND);
- pTexture->Disable();
- }