From 489dba16c32c643160cfa5ef3c266b620a1a51b8 Mon Sep 17 00:00:00 2001
From: Eidolon <furyhunter600@gmail.com>
Date: Tue, 30 Apr 2024 14:56:13 -0500
Subject: [PATCH] Temporarily remove uses of RHI renderbuffers

OpenGL does not have renderbuffers until OpenGL 3.0 (contrast to
GLES which has them starting with 2.0). In order to allow people
with older GPUs to play the game for now (until ANGLE+GLES), I am
removing the use of renderbuffers in the game code. They aren't
needed because nothing actually needs a depth or stencil test yet.
Once HWR2 gets rolling, I'll add these back.

Fixes KartKrew/RingRacers#1
---
 src/hwr2/pass_resource_managers.cpp |  9 ---------
 src/hwr2/pass_resource_managers.hpp |  2 --
 src/hwr2/upscale_backbuffer.cpp     | 10 +---------
 src/hwr2/upscale_backbuffer.hpp     |  1 -
 4 files changed, 1 insertion(+), 21 deletions(-)

diff --git a/src/hwr2/pass_resource_managers.cpp b/src/hwr2/pass_resource_managers.cpp
index 440c0453e..d7ace5d9b 100644
--- a/src/hwr2/pass_resource_managers.cpp
+++ b/src/hwr2/pass_resource_managers.cpp
@@ -40,11 +40,6 @@ void FramebufferManager::prepass(Rhi& rhi)
 			rhi.destroy_texture(main_color_);
 			main_color_ = kNullHandle;
 		}
-		if (main_depth_ != kNullHandle)
-		{
-			rhi.destroy_renderbuffer(main_depth_);
-			main_depth_ = kNullHandle;
-		}
 
 		if (post_colors_[0] != kNullHandle)
 		{
@@ -81,10 +76,6 @@ void FramebufferManager::prepass(Rhi& rhi)
 			TextureWrapMode::kClamp
 		});
 	}
-	if (main_depth_ == kNullHandle)
-	{
-		main_depth_ = rhi.create_renderbuffer({current_width, current_height});
-	}
 
 	if (post_colors_[0] == kNullHandle)
 	{
diff --git a/src/hwr2/pass_resource_managers.hpp b/src/hwr2/pass_resource_managers.hpp
index 62f368070..30e93279e 100644
--- a/src/hwr2/pass_resource_managers.hpp
+++ b/src/hwr2/pass_resource_managers.hpp
@@ -24,7 +24,6 @@ namespace srb2::hwr2
 class FramebufferManager final : public Pass
 {
 	rhi::Handle<rhi::Texture> main_color_;
-	rhi::Handle<rhi::Renderbuffer> main_depth_;
 	std::array<rhi::Handle<rhi::Texture>, 2> post_colors_;
 	rhi::Handle<rhi::Texture> wipe_start_color_;
 	rhi::Handle<rhi::Texture> wipe_end_color_;
@@ -52,7 +51,6 @@ public:
 	void reset_post() noexcept { first_postprocess_ = true; }
 
 	rhi::Handle<rhi::Texture> main_color() const noexcept { return main_color_; }
-	rhi::Handle<rhi::Renderbuffer> main_depth() const noexcept { return main_depth_; }
 
 	rhi::Handle<rhi::Texture> current_post_color() const noexcept { return post_colors_[post_index_]; }
 
diff --git a/src/hwr2/upscale_backbuffer.cpp b/src/hwr2/upscale_backbuffer.cpp
index 5d4d94d16..790f5b332 100644
--- a/src/hwr2/upscale_backbuffer.cpp
+++ b/src/hwr2/upscale_backbuffer.cpp
@@ -41,7 +41,7 @@ void UpscaleBackbuffer::begin_pass(Rhi& rhi, Handle<GraphicsContext> ctx)
 	auto new_renderpass = [&rhi = rhi](AttachmentLoadOp load_op, AttachmentStoreOp store_op)
 	{
 		RenderPassDesc desc {};
-		desc.use_depth_stencil = true;
+		desc.use_depth_stencil = false;
 		desc.color_load_op = load_op;
 		desc.color_store_op = store_op;
 		desc.depth_load_op = load_op;
@@ -58,11 +58,6 @@ void UpscaleBackbuffer::begin_pass(Rhi& rhi, Handle<GraphicsContext> ctx)
 			rhi.destroy_texture(color_);
 			color_ = kNullHandle;
 		}
-		if (depth_)
-		{
-			rhi.destroy_renderbuffer(depth_);
-			depth_ = kNullHandle;
-		}
 
 		TextureDesc color_tex {};
 		color_tex.format = TextureFormat::kRGBA;
@@ -76,8 +71,6 @@ void UpscaleBackbuffer::begin_pass(Rhi& rhi, Handle<GraphicsContext> ctx)
 		depth_tex.width = vid_width;
 		depth_tex.height = vid_height;
 
-		depth_ = rhi.create_renderbuffer(depth_tex);
-
 		if (!renderpass_clear_)
 		{
 			renderpass_clear_ = new_renderpass(AttachmentLoadOp::kClear, AttachmentStoreOp::kStore);
@@ -95,6 +88,5 @@ void UpscaleBackbuffer::begin_pass(Rhi& rhi, Handle<GraphicsContext> ctx)
 	begin_info.render_pass = remake ? renderpass_clear_ : renderpass_;
 	begin_info.clear_color = {0, 0, 0, 1};
 	begin_info.color_attachment = color_;
-	begin_info.depth_stencil_attachment = depth_;
 	rhi.begin_render_pass(ctx, begin_info);
 }
diff --git a/src/hwr2/upscale_backbuffer.hpp b/src/hwr2/upscale_backbuffer.hpp
index 6e806a90e..a60f30172 100644
--- a/src/hwr2/upscale_backbuffer.hpp
+++ b/src/hwr2/upscale_backbuffer.hpp
@@ -19,7 +19,6 @@ namespace srb2::hwr2
 class UpscaleBackbuffer
 {
 	rhi::Handle<rhi::Texture> color_;
-	rhi::Handle<rhi::Renderbuffer> depth_;
 	rhi::Handle<rhi::RenderPass> renderpass_;
 	rhi::Handle<rhi::RenderPass> renderpass_clear_;