我遇到的所有渲染数组数据的例子都类似于以下代码,在您的绘图循环中,您首先调用glEnableClientState来启用您将要使用的内容,完成后再调用glDisableClientState:
void drawScene(void) {
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glBindTexture(GL_TEXTURE_2D, texturePointerA);
glTexCoordPointer(2, GL_FLOAT, 0,textureCoordA);
glVertexPointer(3, GL_FLOAT, 0, verticesA);
glDrawElements(GL_QUADS, numPointsDrawnA, GL_UNSIGNED_BYTE, drawIndicesA);
glBindTexture(GL_TEXTURE_2D, texturePointerB);
glTexCoordPointer(2, GL_FLOAT, 0,textureCoordB);
glVertexPointer(3, GL_FLOAT, 0, verticesB);
glDrawElements(GL_QUADS, numPointsDrawnB, GL_UNSIGNED_BYTE, drawIndicesB);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
}
在我的程序中,我总是使用纹理坐标和顶点数组,所以我认为每帧都启用和禁用它们是毫无意义的。我将glEnableClientState移到了循环外面,像这样:
bool initGL(void) {
//...
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
}
void drawScene(void) {
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D, texturePointerA);
glTexCoordPointer(2, GL_FLOAT, 0,textureCoordA);
glVertexPointer(3, GL_FLOAT, 0, verticesA);
glDrawElements(GL_QUADS, numPointsDrawnA, GL_UNSIGNED_BYTE, drawIndicesA);
glBindTexture(GL_TEXTURE_2D, texturePointerB);
glTexCoordPointer(2, GL_FLOAT, 0,textureCoordB);
glVertexPointer(3, GL_FLOAT, 0, verticesB);
glDrawElements(GL_QUADS, numPointsDrawnB, GL_UNSIGNED_BYTE, drawIndicesB);
}
看起来运行正常。我的问题是:
我需要在某个地方调用glDisableClientState吗?也许在程序关闭时?
同时,这样做可以吗?是否有什么我错过的东西,因为其他人都会在每帧启用和禁用?