From aa187355e4afad0cc385430bab34a6e377b7563f Mon Sep 17 00:00:00 2001
From: Mikulas Florek <mikulas.florek@gamedev.sk>
Date: Fri, 13 Sep 2024 16:46:58 +0200
Subject: [PATCH] tonemap - pixel -> compute shader

---
 data/pipelines/tonemap.shd | 21 +++++++++------------
 src/gui/gui_system.cpp     |  1 +
 src/renderer/pipeline.cpp  | 20 ++++++++++++--------
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/data/pipelines/tonemap.shd b/data/pipelines/tonemap.shd
index 1fc3107ccc..1e313fca5c 100644
--- a/data/pipelines/tonemap.shd
+++ b/data/pipelines/tonemap.shd
@@ -1,23 +1,20 @@
 include "pipelines/common.glsl"
 
-vertex_shader [[
+compute_shader [[
 	struct Output {
 		float2 uv : TEXCOORD0;
 		float4 position : SV_POSITION;
 	};
 
-	Output main(uint vertex_id : SV_VertexID) {
-		Output output;
-		output.position = fullscreenQuad(vertex_id, output.uv);
-		return output;
-	}
-]]
-
-fragment_shader [[
 	cbuffer Data : register(b4) {
-		uint hdr_buffer;
+		uint input;
+		uint output;
 	};
-	float4 main(float2 uv : TEXCOORD0) : SV_TARGET {
-		return float4(ACESFilm(sampleBindlessLod(LinearSamplerClamp, hdr_buffer, uv, 0).rgb), 1);
+
+	[numthreads(16, 16, 1)]
+	void main(uint3 thread_id : SV_DispatchThreadID) {
+		float4 v = bindless_textures[input][thread_id.xy];
+		v = float4(ACESFilm(v.rgb), 1);
+		bindless_rw_textures[output][thread_id.xy] = v;
 	}
 ]]
\ No newline at end of file
diff --git a/src/gui/gui_system.cpp b/src/gui/gui_system.cpp
index 2638898ee6..ae8bd56979 100644
--- a/src/gui/gui_system.cpp
+++ b/src/gui/gui_system.cpp
@@ -80,6 +80,7 @@ struct GUISystemImpl final : GUISystem
 		}
 
 		RenderBufferHandle renderAfterTonemap(const GBuffer& gbuffer, RenderBufferHandle input, Pipeline& pipeline) override {
+			pipeline.setRenderTargets(Span(&input, 1));
 			if (pipeline.getType() != PipelineType::GAME_VIEW) return input;
 			auto* module = (GUIModule*)pipeline.getModule()->getWorld().getModule("gui");
 			Vec2 size = m_system.m_interface->getSize();
diff --git a/src/renderer/pipeline.cpp b/src/renderer/pipeline.cpp
index 28748d7bce..e5d4ab2535 100644
--- a/src/renderer/pipeline.cpp
+++ b/src/renderer/pipeline.cpp
@@ -35,9 +35,6 @@
 #include "texture.h"
 #include <imgui/imgui.h>
 
-// TODO must haves:
-	// TODO check if github CI works
-
 // TODO crashes:
 	// TODO crash when context menu is outside of main window
 
@@ -1053,13 +1050,20 @@ struct PipelineImpl final : Pipeline {
 
 		beginBlock("tonemap");
 		const RenderBufferHandle rb = createRenderbuffer({
-			.format = is_preview ? gpu::TextureFormat::RGBA8 : gpu::TextureFormat::SRGBA,
-			.flags = gpu::TextureFlags::RENDER_TARGET | gpu::TextureFlags::NO_MIPS,
+			.format = gpu::TextureFormat::RGBA8,
+			.flags = gpu::TextureFlags::RENDER_TARGET | gpu::TextureFlags::NO_MIPS | gpu::TextureFlags::COMPUTE_WRITE,
 			.debug_name = "tonemap"
 		});
-		setRenderTargets(Span(&rb, 1));
-		setUniform(toBindless(input, m_renderer.getDrawStream()));
-		drawArray(0, 3, *m_tonemap_shader, 0, gpu::StateFlags::NONE);
+		DrawStream& stream = m_renderer.getDrawStream();
+		struct {
+			gpu::BindlessHandle input;
+			gpu::RWBindlessHandle output;
+		} ubdata {
+			toBindless(input, stream),
+			toRWBindless(rb, stream)
+		};
+		setUniform(ubdata);
+		dispatch(*m_tonemap_shader, (m_viewport.w + 15) / 16, (m_viewport.h + 15) / 16, 1);
 		endBlock();
 		return rb;
 	}