Hi,
I have a problem here. My code is this
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_A_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_B_NV, GL_ZERO, GL_EXPAND_NEGATE_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_C_NV, GL_CONSTANT_COLOR0_NV, GL_SIGNED_NEGATE_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_D_NV, GL_ZERO, GL_EXPAND_NEGATE_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER1_NV, GL_RGB, GL_DISCARD_NV, GL_DISCARD_NV, GL_SPARE0_NV,
GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
And I think is does this: tex0 * 1 + ((-const) * 1)
<=>
A - const
but the value in spare0 always become 0.
I think the answers are often negative. Is it clampled to [0, 1]? I read somewhere that the answer was clamped to [-1, 1]. Anyone know whats wrong?
-Ninja