gl_texture_cache: Implement small texture view cache for swizzles

This fixes cases where the texture swizzle was applied twice on the same
draw to a texture bound to two different slots.

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -977,17 +977,13 @@ void RasterizerOpenGL::SetupTexture(u32 binding, const Tegra::Texture::FullTextu
         glBindTextureUnit(binding, 0);
         return;
     }
-    glBindTextureUnit(binding, view->GetTexture());
-
-    if (view->GetSurfaceParams().IsBuffer()) {
-        return;
-    }
-    // Apply swizzle to textures that are not buffers.
-    view->ApplySwizzle(texture.tic.x_source, texture.tic.y_source, texture.tic.z_source,
-                       texture.tic.w_source);
-
+    const GLuint handle = view->GetTexture(texture.tic.x_source, texture.tic.y_source,
+                                           texture.tic.z_source, texture.tic.w_source);
+    glBindTextureUnit(binding, handle);
+    if (!view->GetSurfaceParams().IsBuffer()) {
         glBindSampler(binding, sampler_cache.GetSampler(texture.tsc));
     }
+}
 
 void RasterizerOpenGL::SetupDrawImages(std::size_t stage_index, const Shader& shader) {
     const auto& maxwell3d = system.GPU().Maxwell3D();
@@ -1015,14 +1011,11 @@ void RasterizerOpenGL::SetupImage(u32 binding, const Tegra::Texture::TICEntry& t
         glBindImageTexture(binding, 0, 0, GL_FALSE, 0, GL_READ_ONLY, GL_R8);
         return;
     }
-    if (!tic.IsBuffer()) {
-        view->ApplySwizzle(tic.x_source, tic.y_source, tic.z_source, tic.w_source);
-    }
     if (entry.is_written) {
         view->MarkAsModified(texture_cache.Tick());
     }
-    glBindImageTexture(binding, view->GetTexture(), 0, GL_TRUE, 0, GL_READ_WRITE,
-                       view->GetFormat());
+    const GLuint handle = view->GetTexture(tic.x_source, tic.y_source, tic.z_source, tic.w_source);
+    glBindImageTexture(binding, handle, 0, GL_TRUE, 0, GL_READ_WRITE, view->GetFormat());
 }
 
 void RasterizerOpenGL::SyncViewport() {

src/video_core/renderer_opengl/gl_texture_cache.cpp

@@ -35,7 +35,7 @@ MICROPROFILE_DEFINE(OpenGL_Texture_Buffer_Copy, "OpenGL", "Texture Buffer Copy",
 namespace {
 
 struct FormatTuple {
-    GLint internal_format;
+    GLenum internal_format;
     GLenum format = GL_NONE;
     GLenum type = GL_NONE;
 };
@@ -387,7 +387,7 @@ void CachedSurface::DecorateSurfaceName() {
 }
 
 void CachedSurfaceView::DecorateViewName(GPUVAddr gpu_addr, std::string prefix) {
-    LabelGLObject(GL_TEXTURE, texture_view.handle, gpu_addr, prefix);
+    LabelGLObject(GL_TEXTURE, main_view.handle, gpu_addr, prefix);
 }
 
 View CachedSurface::CreateView(const ViewParams& view_key) {
@@ -403,15 +403,13 @@ View CachedSurface::CreateViewInner(const ViewParams& view_key, const bool is_pr
 }
 
 CachedSurfaceView::CachedSurfaceView(CachedSurface& surface, const ViewParams& params,
-                                     const bool is_proxy)
-    : VideoCommon::ViewBase(params), surface{surface}, is_proxy{is_proxy} {
-    target = GetTextureTarget(params.target);
-    format = GetFormatTuple(surface.GetSurfaceParams().pixel_format).internal_format;
+                                     bool is_proxy)
+    : VideoCommon::ViewBase(params), surface{surface},
+      format{GetFormatTuple(surface.GetSurfaceParams().pixel_format).internal_format},
+      target{GetTextureTarget(params.target)}, is_proxy{is_proxy} {
     if (!is_proxy) {
-        texture_view = CreateTextureView();
+        main_view = CreateTextureView();
     }
-    current_swizzle =
-        EncodeSwizzle(SwizzleSource::R, SwizzleSource::G, SwizzleSource::B, SwizzleSource::A);
 }
 
 CachedSurfaceView::~CachedSurfaceView() = default;
@@ -454,23 +452,34 @@ void CachedSurfaceView::Attach(GLenum attachment, GLenum target) const {
     }
 }
 
-void CachedSurfaceView::ApplySwizzle(SwizzleSource x_source, SwizzleSource y_source,
+GLuint CachedSurfaceView::GetTexture(SwizzleSource x_source, SwizzleSource y_source,
                                      SwizzleSource z_source, SwizzleSource w_source) {
+    if (GetSurfaceParams().IsBuffer()) {
+        return GetTexture();
+    }
     const u32 new_swizzle = EncodeSwizzle(x_source, y_source, z_source, w_source);
     if (current_swizzle == new_swizzle) {
-        return;
+        return current_view;
     }
     current_swizzle = new_swizzle;
 
+    const auto [entry, is_cache_miss] = view_cache.try_emplace(new_swizzle);
+    OGLTextureView& view = entry->second;
+    if (!is_cache_miss) {
+        current_view = view.handle;
+        return view.handle;
+    }
+    view = CreateTextureView();
+    current_view = view.handle;
+
     std::array swizzle{x_source, y_source, z_source, w_source};
 
-    const GLuint handle = GetTexture();
-    switch (const PixelFormat format = surface.GetSurfaceParams().pixel_format) {
-    case PixelFormat::S8Z24:
+    switch (const PixelFormat format = GetSurfaceParams().pixel_format) {
     case PixelFormat::Z24S8:
     case PixelFormat::Z32FS8:
+    case PixelFormat::S8Z24:
         UNIMPLEMENTED_IF(x_source != SwizzleSource::R && x_source != SwizzleSource::G);
-        glTextureParameteri(handle, GL_DEPTH_STENCIL_TEXTURE_MODE,
+        glTextureParameteri(view.handle, GL_DEPTH_STENCIL_TEXTURE_MODE,
                             GetComponent(format, x_source == SwizzleSource::R));
 
         // Make sure we sample the first component
@@ -481,10 +490,11 @@ void CachedSurfaceView::ApplySwizzle(SwizzleSource x_source, SwizzleSource y_sou
     default: {
         const std::array gl_swizzle = {GetSwizzleSource(swizzle[0]), GetSwizzleSource(swizzle[1]),
                                        GetSwizzleSource(swizzle[2]), GetSwizzleSource(swizzle[3])};
-        glTextureParameteriv(handle, GL_TEXTURE_SWIZZLE_RGBA, gl_swizzle.data());
+        glTextureParameteriv(view.handle, GL_TEXTURE_SWIZZLE_RGBA, gl_swizzle.data());
         break;
     }
     }
+    return view.handle;
 }
 
 OGLTextureView CachedSurfaceView::CreateTextureView() const {

src/video_core/renderer_opengl/gl_texture_cache.h

@@ -83,7 +83,7 @@ public:
     /// Attaches this texture view to the current bound GL_DRAW_FRAMEBUFFER
     void Attach(GLenum attachment, GLenum target) const;
 
-    void ApplySwizzle(Tegra::Texture::SwizzleSource x_source,
+    GLuint GetTexture(Tegra::Texture::SwizzleSource x_source,
                       Tegra::Texture::SwizzleSource y_source,
                       Tegra::Texture::SwizzleSource z_source,
                       Tegra::Texture::SwizzleSource w_source);
@@ -98,7 +98,7 @@ public:
         if (is_proxy) {
             return surface.GetTexture();
         }
-        return texture_view.handle;
+        return main_view.handle;
     }
 
     GLenum GetFormat() const {
@@ -113,12 +113,16 @@ private:
     OGLTextureView CreateTextureView() const;
 
     CachedSurface& surface;
-    GLenum target{};
-    GLenum format{};
+    const GLenum format;
+    const GLenum target;
+    const bool is_proxy;
 
-    OGLTextureView texture_view;
-    u32 current_swizzle{};
-    bool is_proxy{};
+    std::unordered_map<u32, OGLTextureView> view_cache;
+    OGLTextureView main_view;
+
+    // Use an invalid default so it always fails the comparison test
+    u32 current_swizzle = 0xffffffff;
+    GLuint current_view = 0;
 };
 
 class TextureCacheOpenGL final : public TextureCacheBase {