So apparently I have no idea how to do this right, even after searching a whole day on google and so.
Based on some chunks I have found, I wrote this:
[source lang="cpp]
#define VERTEX(x,y,z) glVertex3f(x,y,z)
//#define VERTEX(x,y,z) glTexCoord3f(x,y,z); glVertex3f(x,y,z)
void RenderProjection(void)
{
glEnable(GL_TEXTURE_2D);
glBindTexture( GL_TEXTURE_2D, g_ProjTexture );
{
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
// color
glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR );
glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE );
// alpha
glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_TEXTURE );
glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND0_ALPHA_ARB, GL_SRC_ALPHA );
glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_REPLACE );
};
// Enable projector.
const mat objOrient = identityMat(); // For now only.
g_TexProjector.EnableProjectiveTexturing(objOrient);
// DRAW!
glBegin(GL_QUADS);
{ // 12
// 03
glColor3f(1.0f, 1.0f, 1.0f);
VERTEX( 0, 0, 0 );
VERTEX( 0, 2, 0 );
VERTEX( 2, 2, 0 );
VERTEX( 2, 0, 0 );
};
glEnd();
// Restore settings.
g_TexProjector.DisableProjectiveTexturing();
}
Where I enable/disable projection with:
void CTexProjector::EnableProjectiveTexturing(const mat& texMat)
{
//Set up texture coordinate generation.
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGenfv(GL_S, GL_EYE_PLANE, (float*)&texMat.k0); // 4-component column.
glEnable(GL_TEXTURE_GEN_S);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGenfv(GL_T, GL_EYE_PLANE, (float*)&texMat.k1);
glEnable(GL_TEXTURE_GEN_T);
glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGenfv(GL_R, GL_EYE_PLANE, (float*)&texMat.k2);
glEnable(GL_TEXTURE_GEN_R);
glTexGeni(GL_Q, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGenfv(GL_Q, GL_EYE_PLANE, (float*)&texMat.k3);
glEnable(GL_TEXTURE_GEN_Q);
};
void CTexProjector::DisableProjectiveTexturing(void)
{
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glDisable(GL_TEXTURE_GEN_R);
glDisable(GL_TEXTURE_GEN_Q);
};
And what I see, is just a dark-grey square. My texture is pure-green.
For now, i just set identity as my projection matrix, not to complicate things. But it shouldn't matter anyway. There should be a texture coordinate assigned to each vertex, any value should be good. But it behaves as there wasn't any.
Maybe there's just something missing, or am I doing it all wrong?
Any help appreciated.
/def
