I have the following code that transforms the texture matrix.
static float planeS[4] = { 1.0f, 0.0f, 0.0f, 0.0f };
static float planeT[4] = { 0.0f, 1.0f, 0.0f, 0.0f };
static float planeR[4] = { 0.0f, 0.0f, 1.0f, 0.0f };
static float planeQ[4] = { 0.0f, 0.0f, 0.0f, 1.0f };
static float matProj[16];
static float matModel[16];
static float biasMatrix[16] = { 0.5f, 0.0f, 0.0f, 0.0f,
0.0f, 0.5f, 0.0f, 0.0f,
0.0f, 0.0f, 0.5f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f };
glPushAttrib(GL_ENABLE_BIT);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,textureID);
glTexGeni(GL_S,GL_TEXTURE_GEN_MODE,GL_EYE_LINEAR);
glTexGeni(GL_T,GL_TEXTURE_GEN_MODE,GL_EYE_LINEAR);
glTexGeni(GL_R,GL_TEXTURE_GEN_MODE,GL_EYE_LINEAR);
glTexGeni(GL_Q,GL_TEXTURE_GEN_MODE,GL_EYE_LINEAR);
glTexGenfv(GL_S,GL_EYE_PLANE,planeS);
glTexGenfv(GL_T,GL_EYE_PLANE,planeT);
glTexGenfv(GL_R,GL_EYE_PLANE,planeR);
glTexGenfv(GL_Q,GL_EYE_PLANE,planeQ);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glEnable(GL_TEXTURE_GEN_R);
glEnable(GL_TEXTURE_GEN_Q);
glGetFloatv(GL_PROJECTION_MATRIX,matProj);
glGetFloatv(GL_MODELVIEW_MATRIX,matModel);
glMatrixMode(GL_TEXTURE);
glPushMatrix();
glMultMatrixf(biasMatrix);
glMultMatrixf(matProj);
glMultMatrixf(matModel);
glMatrixMode(GL_MODELVIEW);
This is basically for setting up the texture matrices to correctly project a reflected scene onto a water plane. It all works just fine, but I tried to then create a pixel and vertex shader in GSL and all of the texture transformations went away and I did not get the correct result.
Here are my vertex and texture shaders.
// VERTEX SHADER
void main()
{
// get texture unit 0 coords
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
// get vertex position
gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;
}
// FRAGMENT SHADER
uniform sampler2D reflection;
void main()
{
vec4 color_reflection = texture2D(reflection, gl_TexCoord[0].st);
gl_FragColor = color_reflection;
}
Here are the results I get before using a pixel shader and after. Does anybody know what is wrong with my pixel shader or vertex shader ?
