From ccd636b2fa8b9f270fbe600629dd109e78d00992 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 21 Apr 2021 13:09:03 +0300
Subject: [PATCH] Refactor texture attachment management in Framebuffer

Duplicated code from the attach functions has been collapsed into a
helper function.

Attaching a texture does not need binding it, so there's little point
in deferring the allocation to update_attachment.  By calling the type-
specific allocate function in attach, update_attachment can be simpler.
---
 source/core/framebuffer.cpp | 60 +++++++++++++++----------------------
 source/core/framebuffer.h   |  1 +
 2 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/source/core/framebuffer.cpp b/source/core/framebuffer.cpp
index 795465cb..c90d6a70 100644
--- a/source/core/framebuffer.cpp
+++ b/source/core/framebuffer.cpp
@@ -117,30 +117,22 @@ void Framebuffer::update_attachment(unsigned mask) const
 				else
 					glFramebufferRenderbuffer(GL_FRAMEBUFFER, attch.attachment, GL_RENDERBUFFER, attch.rbuf->get_id());
 			}
-			else if(attch.type==GL_TEXTURE_2D)
+			else if(attch.type)
 			{
-				static_cast<Texture2D *>(attch.tex)->allocate(attch.level);
 				if(ARB_direct_state_access)
-					glNamedFramebufferTexture(id, attch.attachment, attch.tex->get_id(), attch.level);
-				else
+				{
+					if(attch.type==GL_TEXTURE_2D)
+						glNamedFramebufferTexture(id, attch.attachment, attch.tex->get_id(), attch.level);
+					else
+						glNamedFramebufferTextureLayer(id, attch.attachment, attch.tex->get_id(), attch.level, attch.layer);
+				}
+				else if(attch.type==GL_TEXTURE_2D)
 					glFramebufferTexture2D(GL_FRAMEBUFFER, attch.attachment, attch.type, attch.tex->get_id(), attch.level);
-			}
-			else if(attch.type==GL_TEXTURE_3D || attch.type==GL_TEXTURE_2D_ARRAY)
-			{
-				static_cast<Texture3D *>(attch.tex)->allocate(attch.level);
-				if(ARB_direct_state_access)
-					glNamedFramebufferTextureLayer(id, attch.attachment, attch.tex->get_id(), attch.level, attch.layer);
 				else if(attch.type==GL_TEXTURE_2D_ARRAY)
 					glFramebufferTextureLayer(GL_FRAMEBUFFER, attch.attachment, attch.tex->get_id(), attch.level, attch.layer);
-				else
+				else if(attch.type==GL_TEXTURE_3D)
 					glFramebufferTexture3D(GL_FRAMEBUFFER, attch.attachment, attch.type, attch.tex->get_id(), attch.level, attch.layer);
-			}
-			else if(attch.type==GL_TEXTURE_CUBE_MAP)
-			{
-				static_cast<TextureCube *>(attch.tex)->allocate(attch.level);
-				if(ARB_direct_state_access)
-					glNamedFramebufferTextureLayer(id, attch.attachment, attch.tex->get_id(), attch.level, attch.layer);
-				else
+				else if(attch.type==GL_TEXTURE_CUBE_MAP)
 					glFramebufferTexture2D(GL_FRAMEBUFFER, attch.attachment, TextureCube::enumerate_faces(attch.layer), attch.tex->get_id(), attch.level);
 			}
 			else if(ARB_direct_state_access)
@@ -219,48 +211,44 @@ unsigned Framebuffer::get_attachment_index(FramebufferAttachment attch)
 	return attachments.size()-1;
 }
 
-void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
+void Framebuffer::set_texture_attachment(FramebufferAttachment attch, Texture &tex, unsigned level, int layer)
 {
 	if(!id)
 		throw invalid_operation("Framebuffer::attach");
 
 	unsigned i = get_attachment_index(attch);
-	attachments[i].set(rbuf);
+	attachments[i].set(tex, level, layer);
 	update_attachment(1<<i);
 	check_size();
 }
 
-void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, unsigned level)
+void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
 {
 	if(!id)
 		throw invalid_operation("Framebuffer::attach");
 
 	unsigned i = get_attachment_index(attch);
-	attachments[i].set(tex, level, 0);
+	attachments[i].set(rbuf);
 	update_attachment(1<<i);
 	check_size();
 }
 
-void Framebuffer::attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level)
+void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, unsigned level)
 {
-	if(!id)
-		throw invalid_operation("Framebuffer::attach");
+	tex.allocate(level);
+	set_texture_attachment(attch, tex, level, 0);
+}
 
-	unsigned i = get_attachment_index(attch);
-	attachments[i].set(tex, level, layer);
-	update_attachment(1<<i);
-	check_size();
+void Framebuffer::attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level)
+{
+	tex.allocate(level);
+	set_texture_attachment(attch, tex, level, layer);
 }
 
 void Framebuffer::attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level)
 {
-	if(!id)
-		throw invalid_operation("Framebuffer::attach");
-
-	unsigned i = get_attachment_index(attch);
-	attachments[i].set(tex, level, TextureCube::get_face_index(face));
-	update_attachment(1<<i);
-	check_size();
+	tex.allocate(level);
+	set_texture_attachment(attch, tex, level, TextureCube::get_face_index(face));
 }
 
 void Framebuffer::detach(FramebufferAttachment attch)
diff --git a/source/core/framebuffer.h b/source/core/framebuffer.h
index 3054bd64..3086685e 100644
--- a/source/core/framebuffer.h
+++ b/source/core/framebuffer.h
@@ -119,6 +119,7 @@ private:
 	void update_attachment(unsigned) const;
 	void check_size();
 	unsigned get_attachment_index(FramebufferAttachment);
+	void set_texture_attachment(FramebufferAttachment, Texture &, unsigned, int);
 public:
 	void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 	void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
-- 
2.43.0