LTexture.h
void render( GLfloat x, GLfloat y, LFRect* clip = NULL, LFRect* stretch = NULL );
LTexture.cpp
void LTexture::render( GLfloat x, GLfloat y, LFRect* clip, LFRect* stretch )
{ if( mTextureID != 0 ) { glLoadIdentity();//移除之前的变换GLfloat texTop = 0.f;//纹理坐标
GLfloat texBottom = (GLfloat)mImageHeight / (GLfloat)mTextureHeight; GLfloat texLeft = 0.f; GLfloat texRight = (GLfloat)mImageWidth / (GLfloat)mTextureWidth;GLfloat quadWidth = mImageWidth;
GLfloat quadHeight = mImageHeight;if( clip != NULL )//如果裁剪
{ texLeft = clip->x / mTextureWidth; texRight = ( clip->x + clip->w ) / mTextureWidth; texTop = clip->y / mTextureHeight; texBottom = ( clip->y + clip->h ) / mTextureHeight;quadWidth = clip->w;
quadHeight = clip->h; }if( stretch != NULL )//如果拉伸
{ quadWidth = stretch->w; quadHeight = stretch->h; }glTranslatef( x, y, 0.f );//移动
glBindTexture( GL_TEXTURE_2D, mTextureID );//绑定
glBegin( GL_QUADS );//绘制
glTexCoord2f( texLeft, texTop ); glVertex2f( 0.f, 0.f ); glTexCoord2f( texRight, texTop ); glVertex2f( quadWidth, 0.f ); glTexCoord2f( texRight, texBottom ); glVertex2f( quadWidth, quadHeight ); glTexCoord2f( texLeft, texBottom ); glVertex2f( 0.f, quadHeight ); glEnd(); }}
LUtil.cpp
LTexture gStretchedTexture;LFRect gStretchRect = { 0.f, 0.f, SCREEN_WIDTH, SCREEN_HEIGHT };GLenum gFiltering = GL_LINEAR;//纹理过滤bool loadMedia()
{ if( !gStretchedTexture.loadTextureFromFile( "mini_opengl.png" ) ) { printf( "Unable to load mini texture!\n" ); return false; }return true;
}void render()
{ glClear( GL_COLOR_BUFFER_BIT );gStretchedTexture.render( 0.f, 0.f, NULL, &gStretchRect );
glutSwapBuffers();
}void handleKeys( unsigned char key, int x, int y )
{ if( key == 'q' ) { glBindTexture( GL_TEXTURE_2D, gStretchedTexture.getTextureID() );//绑定,然后修改if( gFiltering != GL_LINEAR )
{ glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );//线性拉伸 glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );gFiltering = GL_LINEAR;
} else { glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );//附近拉伸 glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );gFiltering = GL_NEAREST;
}glBindTexture( GL_TEXTURE_2D, NULL );//解除绑定
}}