FBO Inclomplete Errors in OpenGL - c++

I am having an issue with getting a framebuffer incomplete attachment error on the FBO initialized from this code:
glGenFramebuffers(1, &fbo_handle);
glBindFramebuffer(GL_FRAMEBUFFER, fbo_handle);
GLuint render_tex;
glGenTextures(1, &render_tex);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, render_tex);
glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA4, size.x, size.y);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, render_tex, 0);
GLuint depthBuf;
glGenRenderbuffers(1, &depthBuf);
glBindRenderbuffer(GL_RENDERBUFFER, depthBuf);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, size.x, size.y);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuf);
GLenum drawBuffers[] = {GL_COLOR_ATTACHMENT0};
glDrawBuffers(1, drawBuffers);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
Not really sure where to go from here because everything looks like it should work to me. Any help is appreciated.

The issue was that the size was being passed before being set because the first draw was not occurring. Many thanks to #AndonM.Coleman

Related

OpenGL Framebuffer - rendering to texture creates texture with main framebufer content

This is the part of bigger project basically, I'm Creating Framebuffer with color, depth and stencil buffer in a following way:
// Create texture
glGenTextures(1, &m_textureInput);
glBindTexture(GL_TEXTURE_2D, m_textureInput);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, getWidth(), getHeight(), 0, GL_BGRA, GL_UNSIGNED_BYTE, 0);
// Create FBOs
glGenFramebuffers(1, &m_fboInput);
glBindFramebuffer(GL_FRAMEBUFFER, m_fboInput);
// Attach texture to it
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_textureInput, 0);
// Render buffer, depth with stencil
glGenRenderbuffers(1, &m_rbDepthStencilInput);
glBindRenderbuffer(GL_RENDERBUFFER, m_rbDepthStencilInput);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, getWidth(), getHeight());
//Attach depth buffer to FBO
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_rbDepthStencilInput);
//Also attach as a stencil
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, m_rbDepthStencilInput);
status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if(status != GL_FRAMEBUFFER_COMPLETE)
{
// Restore current framebuffer
glBindFramebuffer(GL_FRAMEBUFFER, 0);
return false;
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
I bind it to render to it with:
glBindFramebuffer(GL_FRAMEBUFFER, m_fboInput);
// render
glBindFramebuffer(GL_FRAMEBUFFER, 0);
When i dump attached texture with:
glBindTexture(GL_TEXTURE_2D, m_textureInput);
long imageSize = x * y * 4;
unsigned char *data = new unsigned char[imageSize];
glReadPixels(0,0,x,y, GL_BGRA,GL_UNSIGNED_BYTE,data);
i receive content of main framebuffer (0).
Any idea what I'm dong wrong?
Thanks in advance.
glReadPixels docs say it reads data from the framebuffer. since you bound zero to it before, my guess would be it reads from the default framebuffer.
you can either bind your framebuffer object, then call glReadBuffer with GL_COLOR_ATTACHMENT0 and then do glReadPixels or, maybe more straight forward, use glGetTexImage to directly read from your texture.

Retrieving final scene z-buffer and color buffer

I'm working on opengl 2.1 and opengl es 2.0. I want to implement Depth-of-field effect for whole scene. I know how to do this for single model with shader, but this would require all models to have shader with same code. Is there a way to retrieve final scene depth and color buffer and store them into textures so I could use them again with DOF shader? Or is it a bad idea?
[EDIT]
Finally got it working.
The initialization code looks like this:
glGenFramebuffers(1, &frameBuffer_);
glGenTextures(1, &colorBuffer_);
glGenTextures(1, &depthBuffer_);
//glGenRenderbuffers(1, &depthBuffer_);
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer_);
glBindTexture(GL_TEXTURE_2D, colorBuffer_);
glTexImage2D(
GL_TEXTURE_2D,
0,
GL_RGBA,
width,
height,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(
GL_FRAMEBUFFER,
GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, colorBuffer_, 0);
glBindTexture(GL_TEXTURE_2D, depthBuffer_);
glTexImage2D(
GL_TEXTURE_2D,
0,
GL_DEPTH24_STENCIL8,
width,
height,
0,
GL_DEPTH_STENCIL,
GL_UNSIGNED_INT_24_8,
NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(
GL_FRAMEBUFFER,
GL_DEPTH_ATTACHMENT,
GL_TEXTURE_2D, depthBuffer_, 0);
//glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer_);
//glRenderbufferStorage(
// GL_RENDERBUFFER,
// GL_DEPTH_COMPONENT24,
// width,
// height);
//glFramebufferRenderbuffer(
// GL_FRAMEBUFFER,
// GL_DEPTH_ATTACHMENT,
// GL_RENDERBUFFER, depthBuffer_);
GLenum status;
status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
switch(status) {
case GL_FRAMEBUFFER_COMPLETE:
// Success.
break;
case GL_FRAMEBUFFER_UNSUPPORTED:
LOGE("Frame buffer format not supported.");
break;
default:
LOGE("Framebuffer Error.");
}
And later when rendering first call:
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer_);
Render scene, then call:
glBindFramebuffer(GL_FRAMEBUFFER, 0);
And now anything can be rendered here using depthBuffer_ or colorBuffer_ as OpengGL texture handles.
Use a framebuffer object. They're part of OpenGL-ES-2 and are available as (well supported) extension to OpenGL-2.1.
See
https://github.com/datenwolf/codesamples/tree/master/samples/OpenGL/minimalfbo
for a minimal working example using extensions on desktop OpenGL-2.x

Why does framebuffer freeze in Derelict3?

I am using Derelict3 which uses the specific openGL3 standard and I am having an issue with the screen freezing (not updating) if glEnable(GL_DEPTH_TEST) is called, and the depth buffers not working if it is not. I have noticed that calls to set the clear color and enable depth testing are ignored if they are made prior to setting up the SDL_GL context and reloading Derelict3. I had to make them in the following order:
win=SDL_CreateWindow("3Doodle", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, w, h, flags);
if(!win){
writefln("Error creating SDL window");
SDL_Quit();
}
context=SDL_GL_CreateContext(win);
SDL_GL_SetSwapInterval(1);
glVersion=DerelictGL3.reload();
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glClearColor(0.0, 0.0, 0.0, 1.0);
glClearDepth(1.0);
glCullFace(GL_BACK);
glFrontFace(GL_CCW);
While this sorted out depth culling while writing to the standard double buffer, when I implement a framebuffer object with a renderBuffer as the new depth buffer I get a freeze... the program compiles and runs without warnings, but the rendered image to the screen aligned quad remains fixed. If I comment out glEnable(GL_DEPTH_TEST); the camera moves freely but the the rendered image pays no mind to depth testing and simply draws objects in order.
The framebuffer initialization code is:
//fbo
glEnable (GL_FRAMEBUFFER_SRGB);
glGenFramebuffers(1, &fbo);
assert(fbo > 0);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glGenRenderbuffers(1, &rbo);
assert(rbo > 0);
glBindRenderbuffer(GL_RENDERBUFFER, rbo);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, projMat.w, projMat.h);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rbo);
glBindRenderbuffer(GL_RENDERBUFFER, 0);
glGenTextures(1, &fbon);
assert(fbon > 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, fbon);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, projMat.w, projMat.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, null);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fbon, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glGenTextures(1, &fboc);
assert(fboc > 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, fboc);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, projMat.w, projMat.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, null);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, fboc, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glGenTextures(1, &fbop);
assert(fbop > 0);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, fbop);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, projMat.w, projMat.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, null);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, fbop, 0);
glBindTexture(GL_TEXTURE_2D, 0);
int status=glCheckFramebufferStatus(GL_FRAMEBUFFER);
assert(status == GL_FRAMEBUFFER_COMPLETE);
buffs=[GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2];
glDrawBuffers(3, buffs.ptr);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
The code calling the fbo in draw() is:
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(shad);
glUniformMatrix4fv(viewLoc, 1, GL_TRUE, player.mat.ptr);
current.draw();
glUseProgram(0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
rend.draw();
I am at a loss as the same codes is working in c# as it ought.
My stupidity. Forgot to specify glDepthFunc

Framebuffer Object creation error

EDIT: SOLVED
I encountered a problem while attempting to render into a texture. I create a framebuffer object like this:
glGenTextures(1, &renderFBOtex);
glBindTexture(GL_TEXTURE_2D, renderFBOtex);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glGenRenderbuffers(1, &renderFBOrender);
glBindRenderbuffer(GL_RENDERBUFFER, renderFBOrender);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
glBindRenderbuffer(GL_RENDERBUFFER, 0);
glGenFramebuffers(1, &renderFBO);
glBindFramebuffer(GL_FRAMEBUFFER, renderFBO);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, renderFBOtex, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, renderFBOrender);
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
But the return value of glCheckFrambufferStatus is always GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT.
The problem seems to be with the texture, as it is the same without the Renderbuffer attachment. Drawing into the Framebuffer itself shouldn't be a problem.
Could someone please point out what am I missing here?
Build texture mipmaps before attaching it on the color buffer.
The routine dedicated to this task is glGenerateMipmap.
Another suggestion would be to play with the texture internal format. You are not specifying a sized internal format. Since one of reason of the error is that the texture doesn't have a supported color-renderable internal format, you could give a try.
Problem was in another part of the program. It was a very stupid mistake, which led to use of wrongly initialized values for width and height of the texture. They were both set to 0, hence the incomplete attachment error.
Try this:
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, renderFBOtex, 0);
^^^^
Technically they should make no difference, but some drivers may had this bug.

OpenGL Render to texture (FBO) does not work

I'm trying to use FBO to render to texture and then display the texture, but all I get is a black rectangle. My code is:
Initialization:
#include <GL/glew.h>
#include <GL/gl.h>
#include <GL/glext.h>
#include <assert.h>
// ...
GLuint fbo_, rbo_, tex_;
glGenFramebuffers(1, &fbo_);
glBindFramebuffer(GL_FRAMEBUFFER, fbo_);
glGenRenderbuffers(1, &rbo_);
glBindRenderbuffer(GL_RENDERBUFFER, rbo_);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width_, height_);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rbo_);
glGenTextures(1, &tex_);
glBindTexture(GL_TEXTURE_2D, tex_);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width_, height_, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glGenerateMipmap(GL_TEXTURE_2D);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex_, 0);
assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
Render to the FBO:
glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, width_, height_);
glBindFramebuffer(GL_FRAMEBUFFER, fbo_);
//draw stuff
glPopAttrib();
glBindFramebuffer(GL_FRAMEBUFFER, 0);
Use the texture (the problem is probably in the code above, because if I just use some static texture, the code below works):
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, tex_);
glBegin(GL_QUADS);
glTexCoord2f(0, 0);
glVertex3f(x_, y_, 0);
glTexCoord2f(width_, 0);
glVertex3f(x_ + width_, y_, 0);
glTexCoord2f(width_, height_);
glVertex3f(x_ + width_, y_ + height_, 0);
glTexCoord2f(0, height_);
glVertex3f(x_, y_ + height_, 0);
glEnd();
Could you help me spot the problem?
Make sure the texture you attach is complete if you're going to rely on the default texture environment.
I had the same problem and used genpfault's advice to create a complete texture. Unfortunately, I do not have enough reputation to add a comment so I just added this answer here. Still, the code below may save you some time:
// generate full viewport texture
glGenTextures(1, &fb_tex);
glBindTexture(GL_TEXTURE_2D, fb_tex);
// IMPORTANT: texture must be COMPLETE (mipmaps must be specified..
// or the following parameters can be used if there are none)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
glTexImage2D(
GL_TEXTURE_2D,
0,
GL_RGBA,
width,
height,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
NULL
);
The only thing I changed in my original code was two add the two lines with glTexParameteri. The parameters can be changed depending on the amount of mipmaps you want/have.