Jump to content
  • Advertisement
Sign in to follow this  
djamelha

alpha values getting clamped with FBO texture target

This topic is 4101 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 Im trying to render my scene to a texture and then use this texture in a blending operation. If I disable blending everything looks fine. However when I came to blending I discovered the alpha values were getting clamped to either 1.0 or 0.0. Im really confused and would really appreciate any suggestions. This is how I setup my frame buffer and texture:
// Setup our FBO
glGenFramebuffersEXT(1, &framebuffer);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer);

// Create the render buffer for depth
glGenRenderbuffersEXT(1, &depthBuffer);
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, depthBuffer);
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, TextureWidth, TextureHeight);

// Create texture
glGenTextures(1, &texture1);
glBindTexture(GL_TEXTURE_2D, texture1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB,  TextureWidth, TextureHeight, 0, GL_RGBA, GL_FLOAT, NULL);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

// And attach it to the FBO so we can render to it
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, texture1, 0);
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, depthBuffer);

Share this post


Link to post
Share on other sites
Advertisement
Hmm Ive just read in the opengl bible that with GL_RGBA16F_ARB the values dont get clamped into the range of 0.0,1.0. I think I should be able to solve my problem now, Il post an update with my solution incase anyone else has the same problem.

Share this post


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

  • Advertisement
×

Important Information

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

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!