WebGLFramebuffer uses renderbuffer and texture attachments via WebGLO…

…bject

https://bugs.webkit.org/show_bug.cgi?id=260955
rdar://114750589

Reviewed by Dan Glastonbury.

Framebuffer attachments can be 2d textures, 3d texture layers or
renderbuffers. Use std::variant to encode this instead of
a virtual base class. This removes a lot of unneeded complexity in
the code. This also enables future bugfixes related to non-typesafe
handling of these variants.

When obtaining a pointer to the attached object, use std::variant
instead of WebGLObject*. This way future commits may break the
dependency to a common base class. The objects do not have intrinsic
polymorphic operations, rather their types are always known at the
invocation site, from JS through WebGLRenderingContextBase.

* Source/WebCore/html/canvas/WebGL2RenderingContext.cpp:
(WebCore::WebGL2RenderingContext::framebufferTextureLayer):
(WebCore::WebGL2RenderingContext::getFramebufferAttachmentParameter):
* Source/WebCore/html/canvas/WebGLFramebuffer.cpp:
(WebCore::entryAddMembersToOpaqueRoots):
(WebCore::entryDetachAndClear):
(WebCore::entryAttach):
(WebCore::entryContextSetAttachment):
(WebCore::entryObject):
(WebCore::entryHasObject):
(WebCore::WebGLFramebuffer::setAttachmentForBoundFramebuffer):
(WebCore::WebGLFramebuffer::getAttachmentObject const):
(WebCore::WebGLFramebuffer::removeAttachmentFromBoundFramebuffer):
(WebCore::WebGLFramebuffer::deleteObjectImpl):
(WebCore::WebGLFramebuffer::drawBuffersIfNecessary):
(WebCore::WebGLFramebuffer::addMembersToOpaqueRoots):
(WebCore::WebGLFramebuffer::setAttachmentInternal):
(WebCore::WebGLFramebuffer::TextureAttachment::operator== const):
(WebCore::WebGLFramebuffer::TextureLayerAttachment::operator== const):
(): Deleted.
(WebCore::WebGLFramebuffer::attach): Deleted.
(WebCore::WebGLFramebuffer::getAttachment const): Deleted.
(WebCore::WebGLFramebuffer::removeAttachmentInternal): Deleted.
* Source/WebCore/html/canvas/WebGLFramebuffer.h:
* Source/WebCore/html/canvas/WebGLObject.h:
(WebCore::WebGLObject::isRenderbuffer const): Deleted.
(WebCore::WebGLObject::isTexture const): Deleted.
* Source/WebCore/html/canvas/WebGLRenderbuffer.h:
* Source/WebCore/html/canvas/WebGLRenderingContext.cpp:
(WebCore::WebGLRenderingContext::getFramebufferAttachmentParameter):
* Source/WebCore/html/canvas/WebGLRenderingContextBase.cpp:
(WebCore::WebGLRenderingContextBase::framebufferRenderbuffer):
(WebCore::WebGLRenderingContextBase::framebufferTexture2D):
* Source/WebCore/html/canvas/WebGLTexture.h:

Canonical link: https://commits.webkit.org/267535@main

Source/WebCore/html/canvas/WebGL2RenderingContext.cpp

@@ -677,7 +677,7 @@ void WebGL2RenderingContext::framebufferTextureLayer(GCGLenum target, GCGLenum a
         synthesizeGLError(GraphicsContextGL::INVALID_OPERATION, "framebufferTextureLayer", "no framebuffer bound");
         return;
     }
-    framebufferBinding->setAttachmentForBoundFramebuffer(target, attachment, texTarget, texture, level, layer);
+    framebufferBinding->setAttachmentForBoundFramebuffer(target, attachment, WebGLFramebuffer::TextureLayerAttachment { texture, level, layer });
 }
 
 WebGLAny WebGL2RenderingContext::getInternalformatParameter(GCGLenum target, GCGLenum internalformat, GCGLenum pname)
@@ -2723,10 +2723,10 @@ WebGLAny WebGL2RenderingContext::getFramebufferAttachmentParameter(GCGLenum targ
     if (!validateNonDefaultFramebufferAttachment(functionName, attachment))
         return nullptr;
 
-    RefPtr<WebGLObject> attachmentObject;
+    std::optional<WebGLFramebuffer::AttachmentObject> attachmentObject;
     if (attachment == GraphicsContextGL::DEPTH_STENCIL_ATTACHMENT) {
         attachmentObject = targetFramebuffer->getAttachmentObject(GraphicsContextGL::DEPTH_ATTACHMENT);
-        RefPtr stencilAttachment = targetFramebuffer->getAttachmentObject(GraphicsContextGL::STENCIL_ATTACHMENT);
+        auto stencilAttachment = targetFramebuffer->getAttachmentObject(GraphicsContextGL::STENCIL_ATTACHMENT);
         if (attachmentObject != stencilAttachment) {
             synthesizeGLError(GraphicsContextGL::INVALID_OPERATION, functionName, "different objects bound to DEPTH_ATTACHMENT and STENCIL_ATTACHMENT");
             return nullptr;
@@ -2743,19 +2743,20 @@ WebGLAny WebGL2RenderingContext::getFramebufferAttachmentParameter(GCGLenum targ
         return nullptr;
     }
 
+    const bool isTexture = std::holds_alternative<RefPtr<WebGLTexture>>(*attachmentObject);
     switch (pname) {
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE:
-        if (attachmentObject->isTexture())
+        if (isTexture)
             return static_cast<unsigned>(GraphicsContextGL::TEXTURE);
         return static_cast<unsigned>(GraphicsContextGL::RENDERBUFFER);
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_OBJECT_NAME:
-        if (attachmentObject->isTexture())
-            return static_pointer_cast<WebGLTexture>(WTFMove(attachmentObject));
-        return static_pointer_cast<WebGLRenderbuffer>(WTFMove(attachmentObject));
+        if (isTexture)
+            return std::get<RefPtr<WebGLTexture>>(WTFMove(*attachmentObject));
+        return std::get<RefPtr<WebGLRenderbuffer>>(WTFMove(*attachmentObject));
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL:
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE:
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER:
-        if (!attachmentObject->isTexture())
+        if (!isTexture)
             break;
         FALLTHROUGH;
     case GraphicsContextGL::FRAMEBUFFER_ATTACHMENT_RED_SIZE: