From 2b02f29a2ddfe40639ea0f855bdf257beca59e65 Mon Sep 17 00:00:00 2001
From: Fernando Sahmkow <fsahmkow27@gmail.com>
Date: Mon, 6 Jan 2020 11:43:13 -0400
Subject: [PATCH] GL Backend: Introduce indexed samplers into the GL backend

---
 .../renderer_opengl/gl_rasterizer.cpp         | 34 +++++++++++++++----
 .../renderer_opengl/gl_shader_decompiler.cpp  | 15 ++++++--
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index c428f06e4a..362942e093 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -55,16 +55,20 @@ namespace {
 
 template <typename Engine, typename Entry>
 Tegra::Texture::FullTextureInfo GetTextureInfo(const Engine& engine, const Entry& entry,
-                                               Tegra::Engines::ShaderType shader_type) {
+                                               Tegra::Engines::ShaderType shader_type,
+                                               std::size_t index = 0) {
     if (entry.IsBindless()) {
         const Tegra::Texture::TextureHandle tex_handle =
             engine.AccessConstBuffer32(shader_type, entry.GetBuffer(), entry.GetOffset());
         return engine.GetTextureInfo(tex_handle);
     }
+    const auto& gpu_profile = engine.AccessGuestDriverProfile();
+    const u32 offset =
+        entry.GetOffset() + static_cast<u32>(index * gpu_profile.GetTextureHandlerSize());
     if constexpr (std::is_same_v<Engine, Tegra::Engines::Maxwell3D>) {
-        return engine.GetStageTexture(shader_type, entry.GetOffset());
+        return engine.GetStageTexture(shader_type, offset);
     } else {
-        return engine.GetTexture(entry.GetOffset());
+        return engine.GetTexture(offset);
     }
 }
 
@@ -942,8 +946,15 @@ void RasterizerOpenGL::SetupDrawTextures(std::size_t stage_index, const Shader&
     u32 binding = device.GetBaseBindings(stage_index).sampler;
     for (const auto& entry : shader->GetShaderEntries().samplers) {
         const auto shader_type = static_cast<Tegra::Engines::ShaderType>(stage_index);
-        const auto texture = GetTextureInfo(maxwell3d, entry, shader_type);
-        SetupTexture(binding++, texture, entry);
+        if (!entry.IsIndexed()) {
+            const auto texture = GetTextureInfo(maxwell3d, entry, shader_type);
+            SetupTexture(binding++, texture, entry);
+        } else {
+            for (std::size_t i = 0; i < entry.Size(); ++i) {
+                const auto texture = GetTextureInfo(maxwell3d, entry, shader_type, i);
+                SetupTexture(binding++, texture, entry);
+            }
+        }
     }
 }
 
@@ -952,8 +963,17 @@ void RasterizerOpenGL::SetupComputeTextures(const Shader& kernel) {
     const auto& compute = system.GPU().KeplerCompute();
     u32 binding = 0;
     for (const auto& entry : kernel->GetShaderEntries().samplers) {
-        const auto texture = GetTextureInfo(compute, entry, Tegra::Engines::ShaderType::Compute);
-        SetupTexture(binding++, texture, entry);
+        if (!entry.IsIndexed()) {
+            const auto texture =
+                GetTextureInfo(compute, entry, Tegra::Engines::ShaderType::Compute);
+            SetupTexture(binding++, texture, entry);
+        } else {
+            for (std::size_t i = 0; i < entry.Size(); ++i) {
+                const auto texture =
+                    GetTextureInfo(compute, entry, Tegra::Engines::ShaderType::Compute, i);
+                SetupTexture(binding++, texture, entry);
+            }
+        }
     }
 }
 
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index 2996aaf08f..4b35396f96 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -655,7 +655,8 @@ private:
         u32 binding = device.GetBaseBindings(stage).sampler;
         for (const auto& sampler : ir.GetSamplers()) {
             const std::string name = GetSampler(sampler);
-            const std::string description = fmt::format("layout (binding = {}) uniform", binding++);
+            const std::string description = fmt::format("layout (binding = {}) uniform", binding);
+            binding += sampler.IsIndexed() ? sampler.Size() : 1;
 
             std::string sampler_type = [&]() {
                 if (sampler.IsBuffer()) {
@@ -682,7 +683,11 @@ private:
                 sampler_type += "Shadow";
             }
 
-            code.AddLine("{} {} {};", description, sampler_type, name);
+            if (!sampler.IsIndexed()) {
+                code.AddLine("{} {} {};", description, sampler_type, name);
+            } else {
+                code.AddLine("{} {} {}[{}];", description, sampler_type, name, sampler.Size());
+            }
         }
         if (!ir.GetSamplers().empty()) {
             code.AddNewLine();
@@ -1099,7 +1104,11 @@ private:
         } else if (!meta->ptp.empty()) {
             expr += "Offsets";
         }
-        expr += '(' + GetSampler(meta->sampler) + ", ";
+        if (!meta->sampler.IsIndexed()) {
+            expr += '(' + GetSampler(meta->sampler) + ", ";
+        } else {
+            expr += '(' + GetSampler(meta->sampler) + "[0], ";
+        }
         expr += coord_constructors.at(count + (has_array ? 1 : 0) +
                                       (has_shadow && !separate_dc ? 1 : 0) - 1);
         expr += '(';