shader: compute texture handles read from storage buffers for each draw

Switch 2 shaders can read a texture handle from a storage buffer (Switch
Sports' scenery: a per-object entry of a table whose pointer is in the driver
constant buffer). The bindless handle search looked through the load into its
address and returned the table pointer's constant buffer word as the handle,
which named an arbitrary descriptor; the game repoints that one at transient
render targets every few seconds, so the island and menu lighting flipped
between correct, dark and red.

The search no longer looks into memory loads. A handle it cannot trace is now
built into a small program over constant buffer words, storage buffer words and
integer operations (Shader::Info::handle_programs), which the pipelines evaluate
when they bind the texture. Handles a single evaluation cannot give (one that
changes in a loop) keep the previous search.

2 files changed, 29 insertions, 0 deletions

diff --git a/src/video_core/renderer_opengl/gl_compute_pipeline.cpp b/src/video_core/renderer_opengl/gl_compute_pipeline.cpp
index f0a7baf9aa..eb134e86b5 100644
--- a/src/video_core/renderer_opengl/gl_compute_pipeline.cpp
+++ b/src/video_core/renderer_opengl/gl_compute_pipeline.cpp
@@ -12,6 +12,7 @@
 #include "video_core/renderer_opengl/gl_compute_pipeline.h"
 #include "video_core/renderer_opengl/gl_shader_manager.h"
 #include "video_core/renderer_opengl/gl_shader_util.h"
+#include "video_core/shader_handle_program.h"
 
 namespace OpenGL {
 
@@ -105,6 +106,20 @@ void ComputePipeline::Configure() {
     const auto& cbufs{qmd.const_buffer_config};
     const bool via_header_index{qmd.linked_tsc != 0};
     const auto read_handle{[&](const auto& desc, u32 index) {
+        if constexpr (std::is_same_v<decltype(desc), const Shader::TextureDescriptor&>) {
+            if (desc.handle_program != ~0U) {
+                // Read by the shader from a storage buffer: computed for this dispatch.
+                return TexturePair(VideoCommon::EvaluateTextureHandle(
+                                       info, desc.handle_program, *gpu_memory,
+                                       [&](u32 cbuf) -> GPUVAddr {
+                                           return cbuf < cbufs.size() &&
+                                                          ((qmd.const_buffer_enable_mask >> cbuf) & 1) != 0
+                                                      ? cbufs[cbuf].Address()
+                                                      : GPUVAddr{};
+                                       }),
+                                   via_header_index);
+            }
+        }
         ASSERT(((qmd.const_buffer_enable_mask >> desc.cbuf_index) & 1) != 0);
         const u32 index_offset{index << desc.size_shift};
         const u32 offset{desc.cbuf_offset + index_offset};
diff --git a/src/video_core/renderer_opengl/gl_graphics_pipeline.cpp b/src/video_core/renderer_opengl/gl_graphics_pipeline.cpp
index ecd6544b10..81950279d5 100644
--- a/src/video_core/renderer_opengl/gl_graphics_pipeline.cpp
+++ b/src/video_core/renderer_opengl/gl_graphics_pipeline.cpp
@@ -17,6 +17,7 @@
 #include "video_core/renderer_opengl/gl_shader_manager.h"
 #include "video_core/renderer_opengl/gl_shader_util.h"
 #include "video_core/renderer_opengl/gl_state_tracker.h"
+#include "video_core/shader_handle_program.h"
 #include "video_core/shader_notify.h"
 #include "video_core/texture_cache/texture_cache.h"
 
@@ -308,6 +309,19 @@ bool GraphicsPipeline::ConfigureImpl(bool is_indexed) {
         }
         const auto& cbufs{maxwell3d->state.shader_stages[stage].const_buffers};
         const auto read_handle{[&](const auto& desc, u32 index) {
+            if constexpr (std::is_same_v<decltype(desc), const Shader::TextureDescriptor&>) {
+                if (desc.handle_program != ~0U) {
+                    // Read by the shader from a storage buffer: computed for this draw.
+                    return TexturePair(VideoCommon::EvaluateTextureHandle(
+                                           info, desc.handle_program, *gpu_memory,
+                                           [&](u32 cbuf) -> GPUVAddr {
+                                               return cbuf < cbufs.size() && cbufs[cbuf].enabled
+                                                          ? cbufs[cbuf].address
+                                                          : GPUVAddr{};
+                                           }),
+                                       via_header_index);
+                }
+            }
             ASSERT(cbufs[desc.cbuf_index].enabled);
             const u32 index_offset{index << desc.size_shift};
             const u32 offset{desc.cbuf_offset + index_offset};