From ee21e4ecd372d6a191244dffbc5ac5c7b80150c1 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Thu, 28 May 2020 17:06:22 -0300
Subject: glsl: Squash constant buffers into a single SSBO when we hit the
 limit

Avoids compilation errors at the cost of shader build times and runtime
performance when a game hits the limit of uniform buffers we can use.
---
 src/video_core/renderer_opengl/gl_device.cpp | 46 ++++++++++++++++++----------
 1 file changed, 29 insertions(+), 17 deletions(-)

(limited to 'src/video_core/renderer_opengl/gl_device.cpp')

diff --git a/src/video_core/renderer_opengl/gl_device.cpp b/src/video_core/renderer_opengl/gl_device.cpp
index e1b245288..d20547c04 100644
--- a/src/video_core/renderer_opengl/gl_device.cpp
+++ b/src/video_core/renderer_opengl/gl_device.cpp
@@ -6,6 +6,7 @@
 #include <array>
 #include <cstddef>
 #include <cstring>
+#include <limits>
 #include <optional>
 #include <vector>
 
@@ -26,24 +27,27 @@ constexpr u32 ReservedUniformBlocks = 1;
 
 constexpr u32 NumStages = 5;
 
-constexpr std::array LimitUBOs = {GL_MAX_VERTEX_UNIFORM_BLOCKS, GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS,
-                                  GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS,
-                                  GL_MAX_GEOMETRY_UNIFORM_BLOCKS, GL_MAX_FRAGMENT_UNIFORM_BLOCKS};
+constexpr std::array LimitUBOs = {
+    GL_MAX_VERTEX_UNIFORM_BLOCKS,          GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS,
+    GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS, GL_MAX_GEOMETRY_UNIFORM_BLOCKS,
+    GL_MAX_FRAGMENT_UNIFORM_BLOCKS,        GL_MAX_COMPUTE_UNIFORM_BLOCKS};
 
 constexpr std::array LimitSSBOs = {
-    GL_MAX_VERTEX_SHADER_STORAGE_BLOCKS, GL_MAX_TESS_CONTROL_SHADER_STORAGE_BLOCKS,
+    GL_MAX_VERTEX_SHADER_STORAGE_BLOCKS,          GL_MAX_TESS_CONTROL_SHADER_STORAGE_BLOCKS,
     GL_MAX_TESS_EVALUATION_SHADER_STORAGE_BLOCKS, GL_MAX_GEOMETRY_SHADER_STORAGE_BLOCKS,
-    GL_MAX_FRAGMENT_SHADER_STORAGE_BLOCKS};
+    GL_MAX_FRAGMENT_SHADER_STORAGE_BLOCKS,        GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS};
 
-constexpr std::array LimitSamplers = {
-    GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS, GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS,
-    GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS, GL_MAX_GEOMETRY_TEXTURE_IMAGE_UNITS,
-    GL_MAX_TEXTURE_IMAGE_UNITS};
+constexpr std::array LimitSamplers = {GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS,
+                                      GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS,
+                                      GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS,
+                                      GL_MAX_GEOMETRY_TEXTURE_IMAGE_UNITS,
+                                      GL_MAX_TEXTURE_IMAGE_UNITS,
+                                      GL_MAX_COMPUTE_TEXTURE_IMAGE_UNITS};
 
-constexpr std::array LimitImages = {GL_MAX_VERTEX_IMAGE_UNIFORMS,
-                                    GL_MAX_TESS_CONTROL_IMAGE_UNIFORMS,
-                                    GL_MAX_TESS_EVALUATION_IMAGE_UNIFORMS,
-                                    GL_MAX_GEOMETRY_IMAGE_UNIFORMS, GL_MAX_FRAGMENT_IMAGE_UNIFORMS};
+constexpr std::array LimitImages = {
+    GL_MAX_VERTEX_IMAGE_UNIFORMS,          GL_MAX_TESS_CONTROL_IMAGE_UNIFORMS,
+    GL_MAX_TESS_EVALUATION_IMAGE_UNIFORMS, GL_MAX_GEOMETRY_IMAGE_UNIFORMS,
+    GL_MAX_FRAGMENT_IMAGE_UNIFORMS,        GL_MAX_COMPUTE_IMAGE_UNIFORMS};
 
 template <typename T>
 T GetInteger(GLenum pname) {
@@ -85,6 +89,13 @@ u32 Extract(u32& base, u32& num, u32 amount, std::optional<GLenum> limit = {}) {
     return std::exchange(base, base + amount);
 }
 
+std::array<u32, Tegra::Engines::MaxShaderTypes> BuildMaxUniformBuffers() noexcept {
+    std::array<u32, Tegra::Engines::MaxShaderTypes> max;
+    std::transform(LimitUBOs.begin(), LimitUBOs.end(), max.begin(),
+                   [](GLenum pname) { return GetInteger<u32>(pname); });
+    return max;
+}
+
 std::array<Device::BaseBindings, Tegra::Engines::MaxShaderTypes> BuildBaseBindings() noexcept {
     std::array<Device::BaseBindings, Tegra::Engines::MaxShaderTypes> bindings;
 
@@ -159,7 +170,8 @@ bool IsASTCSupported() {
 
 } // Anonymous namespace
 
-Device::Device() : base_bindings{BuildBaseBindings()} {
+Device::Device()
+    : max_uniform_buffers{BuildMaxUniformBuffers()}, base_bindings{BuildBaseBindings()} {
     const std::string_view vendor = reinterpret_cast<const char*>(glGetString(GL_VENDOR));
     const auto renderer = reinterpret_cast<const char*>(glGetString(GL_RENDERER));
     const std::vector extensions = GetExtensions();
@@ -194,7 +206,9 @@ Device::Device() : base_bindings{BuildBaseBindings()} {
 }
 
 Device::Device(std::nullptr_t) {
-    uniform_buffer_alignment = 0;
+    max_uniform_buffers.fill(std::numeric_limits<u32>::max());
+    uniform_buffer_alignment = 4;
+    shader_storage_alignment = 4;
     max_vertex_attributes = 16;
     max_varyings = 15;
     has_warp_intrinsics = true;
@@ -202,8 +216,6 @@ Device::Device(std::nullptr_t) {
     has_vertex_viewport_layer = true;
     has_image_load_formatted = true;
     has_variable_aoffi = true;
-    has_component_indexing_bug = false;
-    has_precise_bug = false;
 }
 
 bool Device::TestVariableAoffi() {
-- 
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