我有一个完全可用的绘图程序,如下所示:
glEnable(GL_TEXTURE_2D);
glMatrixMode(GL_MODELVIEW);
{
glBindTexture(GL_TEXTURE_2D, [texture name]);
GLsizei stride = sizeof(quads[0].tl);
glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(TQuad2D), quads, GL_STATIC_DRAW);
glVertexPointer(2, GL_FLOAT, stride, (void *)offsetof(TVertex2D, pos));
glEnableClientState(GL_VERTEX_ARRAY);
glTexCoordPointer(2, GL_FLOAT, stride, (void *)offsetof(TVertex2D, tex));
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
glBindTexture(GL_TEXTURE_2D, 0);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisable(GL_TEXTURE_2D);
在上述内容之前或之后,我想画一条简单的线,例如下面这条。这本身是有效的,但如果与上述程序结合使用,则会出现506错误,即 GL_INVALID_FRAMEBUFFER_OPERATION
。
GLfloat verts[4];
verts[0] = 0;
verts[1] = 0;
verts[2] = 600;
verts[3] = 600;
glColor4f(0.0f,1.0f,0.0f,1.0f);
glVertexPointer(2, GL_FLOAT, 0, &verts);
glEnableClientState(GL_VERTEX_ARRAY);
glDrawArrays(GL_LINES, 0, 2);
glDisableClientState(GL_VERTEX_ARRAY);
GLErrCheck(@"err");
我可能忘记了重置某些GL状态,但我找不出来。