Attaching Framebuffer to Texture error - c++

I am trying to implement shadow mapping with the tutorial here, however when I try to use this code to attach a Framebuffer to a texture it fails. My OpenGL context is 3.1 and I believe i have an Intel 3000 series graphics card. The code fails at 2 points. The first failure is at glFramebufferTexture2D, which gives error code 1282 (Not sure what enumeration that corresponds too). I believe this error is causing the assert assi later in the code to fail. I have tried code from similar questions but they do not seem to work in this case.
glGenFramebuffers(1, &MObject::fbo);
glGenTextures(1, &MObject::shadowMap);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, windowWidth, windowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glBindFramebuffer(GL_FRAMEBUFFER, MObject::fbo);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, MObject::shadowMap, 0);
GLenum err = glGetError(); // Error code: 1282
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
assi(status == GL_FRAMEBUFFER_COMPLETE, "FBO error!"); // Expression is false, abort called.

Yea so I forgot glBindTexture. I hate myself. Thank you Hectigo!

Related

Why is glCheckFramebufferStatus always 36054 for GL_DEPTH_COMPONENT on OpenGL ES 3.1+?

I render the color (GL_COLOR_ATTACHMENT0) and depth (GL_DEPTH_ATTACHMENT) of my scene into a FBO, which works fine on PC with OpenGL 4+.
But on my Smartphone with OpenGL ES 3.1+ I always get for the depth via glCheckFramebufferStatus(GL_FRAMEBUFFER) the status = 36054.
glGenTextures(1, &m_textCol);
glBindTexture(GL_TEXTURE_2D, m_textCol);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, wth, hgt, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glGenTextures(1, &m_textDepth);
glBindTexture(GL_TEXTURE_2D, m_textDepth);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, wth, hgt, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
GLuint framebuffer;
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_textCol, 0);
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER); always 36053 -> ok
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, m_textDepth, 0);
status = glCheckFramebufferStatus(GL_FRAMEBUFFER); // always 36054 -> not ok
I tried it also with
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, wth, hgt, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
but no change.
Has maybe someone an idea what I'm doing wrong? Thanks.
Status 36054 is GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT.
If we look at Section 9.4 of the OpenGL ES3.1 specification, it lists the following valid internalFormat values for depth attachments:
DEPTH_COMPONENT16
DEPTH_COMPONENT24
DEPTH_COMPONENT32F
DEPTH24_STENCIL8
DEPTH32F_STENCIL8
Note that the last two also contain a stencil part. You can use these for the depth component and ignore the stencil attachment if you do not need it. Especially DEPTH24_STENCIL8 has a good chance of being widely supported.

OpenGL ES Depth Buffer rendering (iOS simulator VS real device)

When rendering the depth buffer with the iOS simulator Getting the true z value from the depth buffer , all is fine.
But the rendering on real device gives bad result: the depth is rendered with only few values (there is no fade) like when you display an image into a 256 values color range.
Here is the code for the fbo generation:
glGenFramebuffers(1, &sceneFBO);
glGenTextures(2, textures_scene);
glBindTexture(GL_TEXTURE_2D, textures_scene[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, widthResolution, heightResolution, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, textures_scene[1]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, widthResolution, heightResolution, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
//TODO: GL_DEPTH_COMPONENT cannot be GL_UNSIGNED_BYTE ?
glBindFramebuffer(GL_FRAMEBUFFER, sceneFBO);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures_scene[0], 0);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, textures_scene[1], 0);
It seems that the only working value for GL_DEPTH_ATTACHMENT fbo is GL_UNSIGNED_INT. But it is not enough to render the depth...
PS: I don't want to display again the scene into a GL_COLOR_ATTACHMENT0 with the z-values in order to have a correct depth (for performance reasons) nor use OpenGL ES3.0 or the new metal (iPhone4s support).
Any idea?
There is no depth buffer support in ES 1 or 2. See the answer to this question : glReadPixels doesn't read depth buffer values on iOS
Seems, that it's not possible to use GL_UNSIGNED_BYTE as type parameter together with GL_DEPTH_COMPONENT as internalformat, only GL_UNSIGNED_SHORT and GL_UNSIGNED_INT are allowed according to the GL_OES_depth_texture extension spec: https://www.khronos.org/registry/gles/extensions/OES/OES_depth_texture.txt
I finally put the z value in the alpha part of the scene (I don't use transparency for this fbo).
color.w=(gl_postion.z-near)/(far-near)
A little mcgyver but it does the job.

glFrameBuffer2D blending doesn't work

I'm having trouble with rendering to texture output from this opengl example: http://en.wikibooks.org/wiki/OpenGL_Programming/Modern_OpenGL_Tutorial_Text_Rendering_01
My framebuffer is setup as follows:
glGenTextures(1, &back_text);
glBindTexture(GL_TEXTURE_2D, back_text);
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_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, WINDOW_WIDTH, WINDOW_HEIGHT, 0, GL_BGRA, GL_UNSIGNED_BYTE, 0);
glGenFramebuffersEXT(1, &font_buffer);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, font_buffer);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, back_text, 0);
In best case I can get filled rectangle with color where letter should appear (it appears like alpha is always 1.0).
I've tried original example and it works correctly.
My question is: do I need to enable something to make this work or do I need to take different approach?
Edit:
It turns out that I need to use
glutInitContextVersion(2,0); instead of
glutInitContextVersion(3,2); and world is happy place!! :)

Shadow mapping. Framebuffer error 36060

I am doing this from a tutorial and i have exactly the code from the tutorial. But for some reason is not working. So i debugged and i saw that it had a 36060 error also know as GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER as far as i know and i don't really understand why. I searched for answers and everybody said about glReadBuffer(GL_NONE); But even with that i get the same error.
bool ShadowMapFBO::Init(unsigned int WindowWidth, unsigned int WindowHeight)
{
// Create the FBO
glGenFramebuffers(1, &m_fbo);
// Create the depth buffer
glGenTextures(1, &m_shadowMap);
glBindTexture(GL_TEXTURE_2D, m_shadowMap);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, WindowWidth, WindowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_fbo);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, m_shadowMap, 0);
// Disable writes to the color buffer
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
GLenum Status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (Status != GL_FRAMEBUFFER_COMPLETE) {
printf("FB error, status: 0x%x\n", Status);
return false;
}
return true;
}
EDIT: seems like glReadBuffer doesn't work at all and I don't know why. I tried glGetError and i got no error
I solved the problem. Seems like I had to add glBindFramebuffer(GL_READ_FRAMEBUFFER, m_fbo);
Seems like if you don't need it if you have a nvidia video card. I had a intel integrated video card and that's why it didn't worked.

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.