Hello all,
I’m trying to get my feet wet with using frame buffers. I’ve set up a frame buffer based off of a number of online tutorials, but the texture that I attached to it doesn’t seem to be receiving the drawing. I like to debug these myself whenever possible, but I don’t know how to check inside the frame buffer to see what’s going on at runtime. Here is how I set up the frame buffer. Can anyone tell me if there is something missing?
bool Setup_FrameBuffers()
{
// FramebufferName, renderedTexture and depthrenderbuffer are global GLuint
pglGenFramebuffers(1, &FramebufferName);
pglBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);
glGenTextures(1, &renderedTexture);
// Texture
glBindTexture(GL_TEXTURE_2D, renderedTexture);
glTexImage2D(GL_TEXTURE_2D, 0,GL_RGB, 640, 385, 0,GL_RGB, GL_UNSIGNED_BYTE, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
pglFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, renderedTexture, 0);
glBindTexture(GL_TEXTURE_2D, 0);
// The depth buffer
pglGenRenderbuffers(1, &depthrenderbuffer);
pglBindRenderbuffer(GL_RENDERBUFFER, depthrenderbuffer);
pglRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, 640, 385);
pglFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthrenderbuffer);
GLenum DrawBuffers[1] = {GL_COLOR_ATTACHMENT0};
pglDrawBuffers(1, DrawBuffers);
if(pglCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
return false;
pglBindFramebuffer(GL_FRAMEBUFFER, 0);
return true;
}
The fragment shader I use is:
#version 330
varying vec3 lighted_color;
layout(location = 0) out vec4 output_color;
void main (void)
{
output_color = vec4(lighted_color, 1.0);
}
Basically I 1) Switch to the frame buffer, 2) render the scene, 3) switch back to the screen, and 4) draw the rendered texture. Nothing appears.
If I bypass the whole thing and render directly to the scene to the screen, (without this frame buffer business), it appears fine. If I switch out a pregenerated texture for step 4, it appears fine as well, but the rendered texture never appears. Suggestions?
PS: The “p” in front of some glFunctions is just a reminder to me that I had to pull them in from extensions. They are otherwise the same glFunctions.