GLenum WebGLFramebuffer::checkStatus(const char** reason) const
{
unsigned count = 0;
GLsizei width = 0, height = 0, depth = 0;
WebGLAttachment* depthAttachment = nullptr;
WebGLAttachment* stencilAttachment = nullptr;
WebGLAttachment* depthStencilAttachment = nullptr;
bool isWebGL2OrHigher = context()->isWebGL2OrHigher();
for (const auto& it : m_attachments) {
WebGLAttachment* attachment = it.value.get();
if (!isAttachmentComplete(attachment, it.key, reason))
return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
if (!attachment->valid()) {
*reason = "attachment is not valid";
return GL_FRAMEBUFFER_UNSUPPORTED;
}
if (!attachment->format()) {
*reason = "attachment is an unsupported format";
return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
}
switch (it.key) {
case GL_DEPTH_ATTACHMENT:
depthAttachment = attachment;
break;
case GL_STENCIL_ATTACHMENT:
stencilAttachment = attachment;
break;
case GL_DEPTH_STENCIL_ATTACHMENT:
depthStencilAttachment = attachment;
break;
}
// Note: In GLES 3, images for a framebuffer need not to have the same dimensions to be framebuffer complete.
// However, in Direct3D 11, on top of which OpenGL ES 3 behavior is emulated in Windows, all render targets
// must have the same size in all dimensions. In order to have consistent WebGL 2 behaviors across platforms,
// we generate FRAMEBUFFER_INCOMPLETE_DIMENSIONS in this situation.
if (!count) {
width = attachment->width();
height = attachment->height();
depth = attachment->depth();
} else {
if (width != attachment->width() || height != attachment->height() || depth != attachment->depth()) {
*reason = "attachments do not have the same dimensions";
return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS;
}
}
++count;
}
if (!count) {
*reason = "no attachments";
return GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT;
}
// WebGL 1 specific: no conflicting DEPTH/STENCIL/DEPTH_STENCIL attachments.
if (!isWebGL2OrHigher
&& ((depthStencilAttachment && (depthAttachment || stencilAttachment))
|| (depthAttachment && stencilAttachment))) {
*reason = "conflicting DEPTH/STENCIL/DEPTH_STENCIL attachments";
return GL_FRAMEBUFFER_UNSUPPORTED;
}
if (isWebGL2OrHigher
&& (depthAttachment && stencilAttachment && depthAttachment->object() != stencilAttachment->object())) {
*reason = "both DEPTH/STENCIL attachments are present and not the same image";
return GL_FRAMEBUFFER_UNSUPPORTED;
}
return GL_FRAMEBUFFER_COMPLETE;
}
