/** Verify rendered polygon anisotropy.
*
* @param gl OpenGL functions wrapper
*
* @return Returns points value. Less points means better anisotropy (smoother strips).
*/
GLuint TextureFilterAnisotropicDrawingTestCase::verifyScene(const glw::Functions& gl)
{
std::vector<GLubyte> pixels;
pixels.resize(32 * 8 * 4);
gl.readPixels(0, 23, 32, 8, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
GLU_EXPECT_NO_ERROR(gl.getError(), "glReadPixels");
GLuint sum = 0;
GLubyte last = 0;
GLubyte current = 0;
for (int j = 0; j < 8; ++j)
{
for (int i = 0; i < 32; ++i)
{
current = pixels[(i + j * 32) * 4];
if (i > 0)
sum += deAbs32((int)current - (int)last);
last = current;
}
}
return sum;
}
