Jump to content
  • Advertisement
Sign in to follow this  
pmangalvedkar

Problem with FBO and Fragment Shader

This topic is 4093 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi, I am trying to use a triangle strip texture to draw a cylinder. I use a fragment shader to calculate the points for the triangles. The results are stored in FBOs. Then I copy it to a PBO and render it as usual. But I am not able to get the result I expect. If I dont use the shader and just use the CPU to do the calculations, I can see the cylinders.I dont know where I am going wrong. Can anybody help me? The code is as follows: //******** render to FBO **************** //******** bind the buffer ************** glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, fb_handle); GLenum dbuffers[] = {GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT}; glDrawBuffers(2, dbuffers); //******** render the buffer using quad*************** glDisable (GL_DEPTH_TEST); glDepthMask (GL_FALSE); glDisable (GL_CULL_FACE); glEnable (GL_TEXTURE_2D); glActiveTextureARB (GL_TEXTURE0_ARB); glBindTexture (GL_TEXTURE_2D, tex_handle); glActiveTextureARB (GL_TEXTURE1_ARB); glBindTexture (GL_TEXTURE_2D, treedata_handle); cgGLEnableProfile (CG_PROFILE_ARBFP1); cgGLBindProgram (fragmentprogram); cgGLEnableTextureParameter (treedata); // This contains my dataset cgGLEnableTextureParameter (texture_data); // This contains the texture cgSetParameter1f (GPUindex, (float)(2*i+1)/(float)(2*arraysize)); glMatrixMode (GL_PROJECTION); glPushMatrix (); glLoadIdentity (); gluOrtho2D (0.0, 2.0, 0.0, 56.0); glMatrixMode (GL_MODELVIEW); glPushMatrix (); glLoadIdentity (); int viewport[4]; glGetIntegerv (GL_VIEWPORT, viewport); glViewport (0, 0, 2, 56); glClampColorARB (GL_CLAMP_VERTEX_COLOR_ARB, GL_FALSE); glBegin (GL_QUADS); glColor3f (0.0, 1.0, 0.0); glTexCoord2f (0.0, 0.0); glVertex2f (0.0, 0.0); glTexCoord2f (1.0, 0.0); glVertex2f (2.0, 0.0); glTexCoord2f (1.0, 1.0); glVertex2f (2.0, 56.0); glTexCoord2f (0.0, 1.0); glVertex2f (0.0, 56.0); glEnd (); glDisable (GL_TEXTURE_2D); cgGLDisableTextureParameter (treedata); cgGLDisableTextureParameter (texture_data); cgGLDisableProfile (CG_PROFILE_ARBFP1); //*********copy from FBO to PBO*********************** glReadBuffer (GL_COLOR_ATTACHMENT0_EXT); glBindBufferARB (GL_PIXEL_PACK_BUFFER_EXT, vbo_vertices_handle); glReadPixels (0, 0, 2, 56, GL_RGBA, GL_FLOAT, 0); glReadBuffer (GL_COLOR_ATTACHMENT1_EXT); glBindBufferARB (GL_PIXEL_PACK_BUFFER_EXT, vbo_normals_handle); glReadPixels (0, 0, 2, 56, GL_RGBA, GL_FLOAT, 0); glReadBuffer (GL_NONE); glBindBufferARB (GL_PIXEL_PACK_BUFFER_EXT, 0); glViewport (viewport[0],viewport[1],viewport[2],viewport[3]); glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0); glDrawBuffer (GL_BACK); glEnable (GL_DEPTH_TEST); glDepthMask (GL_TRUE); glEnable (GL_CULL_FACE); glPopMatrix (); glMatrixMode (GL_PROJECTION); glPopMatrix (); glMatrixMode (GL_MODELVIEW); //******** render the VBO as usual ************ /* ------------- -------------- -------------- */ [Edited by - pmangalvedkar on May 10, 2007 1:57:11 PM]

Share this post


Link to post
Share on other sites
Advertisement
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!