View Full Version : matrix from gl to glsl
05-11-2004, 12:05 AM
.. i'm using gl_TextureMatrix to catch a matrix from gl .. its working pretty well, but the index correnponds on the bound texture .. thats sucks .. any ideas ???
05-11-2004, 12:59 AM
ok .. i'm using gl_modelviewmatrix .. a little bit stupid .. but it works ..
05-11-2004, 01:46 AM
Is it so hard to take a look at the glsl-specs? There are plenty of matrices predefined (although there could be some more like in ARB_VP/ARB_FP) :
mat4 gl_ModelViewMatrix mat4 gl_ModelViewMatrix mat4 gl_ProjectionMatrix mat4 gl_ModelViewProjectionMatrix mat3 gl_NormalMatrix mat4 gl_TextureMatrix[gl_MaxTextureCoordsARB]
P.S. : Why is using gl_ModelViewMatrix stupid?
05-11-2004, 04:05 AM
because i'm using a two pass shader and need the matrix in both passes. when i'm using the modelMatrix i have to pop after my first pass for drawing my scenen .. if i could store in textureMatrix and haven't this problems .. but i'm not sure, how i can maniuplate the index of gl_TextureMatrix ..
is the index equal to the bound name of the bound texture ??
.. to write to the textureMatrix i'm just calling glMatrixMode(GL_TEXTURE); how do i know the right index for gl_TextureMatrix and gl_MultiTexCoord0 in my shader?? oi read a lot about textures in the read, orange and blue book, but i didn't found the answer ..
05-11-2004, 08:46 AM
textures in GLSL dont refer to 'texture objects' but 'texture units', so if you bind a texture object to texture unit 0 and change its matrix then gl_TextureMatrix refers to the matrix of that texture unit
You know what texture it refers to because you bound the texture to that texture unit before calling the shader.
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