video_core/compatible_formats: Table to test if two formats are legal to view or copy

Add a flat table to test if it's legal to create a texture view between
two formats or copy betweem them.

This table is based on ARB_copy_image and ARB_texture_view. Copies are
more permissive than views.

src/video_core/CMakeLists.txt

@@ -3,6 +3,8 @@ add_library(video_core STATIC
     buffer_cache/buffer_cache.h
     buffer_cache/map_interval.cpp
     buffer_cache/map_interval.h
+    compatible_formats.cpp
+    compatible_formats.h
     dirty_flags.cpp
     dirty_flags.h
     dma_pusher.cpp

src/video_core/compatible_formats.cpp

@@ -0,0 +1,162 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <bitset>
+#include <cstddef>
+
+#include "video_core/compatible_formats.h"
+#include "video_core/surface.h"
+
+namespace VideoCore::Surface {
+
+namespace {
+
+// Compatibility table taken from Table 3.X.2 in:
+// https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_texture_view.txt
+
+constexpr std::array VIEW_CLASS_128_BITS = {
+    PixelFormat::RGBA32F,
+    PixelFormat::RGBA32UI,
+};
+// Missing formats:
+// PixelFormat::RGBA32I
+
+constexpr std::array VIEW_CLASS_96_BITS = {
+    PixelFormat::RGB32F,
+};
+// Missing formats:
+// PixelFormat::RGB32UI,
+// PixelFormat::RGB32I,
+
+constexpr std::array VIEW_CLASS_64_BITS = {
+    PixelFormat::RGBA16F, PixelFormat::RG32F,   PixelFormat::RGBA16UI, PixelFormat::RG32UI,
+    PixelFormat::RGBA16U, PixelFormat::RGBA16F, PixelFormat::RGBA16S,
+};
+// Missing formats:
+// PixelFormat::RGBA16I
+// PixelFormat::RG32I
+
+// TODO: How should we handle 48 bits?
+
+constexpr std::array VIEW_CLASS_32_BITS = {
+    PixelFormat::RG16F,        PixelFormat::R11FG11FB10F, PixelFormat::R32F,
+    PixelFormat::A2B10G10R10U, PixelFormat::RG16UI,       PixelFormat::R32UI,
+    PixelFormat::RG16I,        PixelFormat::R32I,         PixelFormat::ABGR8U,
+    PixelFormat::RG16,         PixelFormat::ABGR8S,       PixelFormat::RG16S,
+    PixelFormat::RGBA8_SRGB,   PixelFormat::E5B9G9R9F,    PixelFormat::BGRA8,
+    PixelFormat::BGRA8_SRGB,
+};
+// Missing formats:
+// PixelFormat::RGBA8UI
+// PixelFormat::RGBA8I
+// PixelFormat::RGB10_A2_UI
+
+// TODO: How should we handle 24 bits?
+
+constexpr std::array VIEW_CLASS_16_BITS = {
+    PixelFormat::R16F, PixelFormat::RG8UI, PixelFormat::R16UI, PixelFormat::R16I,
+    PixelFormat::RG8U, PixelFormat::R16U,  PixelFormat::RG8S,  PixelFormat::R16S,
+};
+// Missing formats:
+// PixelFormat::RG8I
+
+constexpr std::array VIEW_CLASS_8_BITS = {
+    PixelFormat::R8UI,
+    PixelFormat::R8U,
+};
+// Missing formats:
+// PixelFormat::R8I
+// PixelFormat::R8S
+
+constexpr std::array VIEW_CLASS_RGTC1_RED = {
+    PixelFormat::DXN1,
+};
+// Missing formats:
+// COMPRESSED_SIGNED_RED_RGTC1
+
+constexpr std::array VIEW_CLASS_RGTC2_RG = {
+    PixelFormat::DXN2UNORM,
+    PixelFormat::DXN2SNORM,
+};
+
+constexpr std::array VIEW_CLASS_BPTC_UNORM = {
+    PixelFormat::BC7U,
+    PixelFormat::BC7U_SRGB,
+};
+
+constexpr std::array VIEW_CLASS_BPTC_FLOAT = {
+    PixelFormat::BC6H_SF16,
+    PixelFormat::BC6H_UF16,
+};
+
+// Compatibility table taken from Table 4.X.1 in:
+// https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_copy_image.txt
+
+constexpr std::array COPY_CLASS_128_BITS = {
+    PixelFormat::RGBA32UI,   PixelFormat::RGBA32F,   PixelFormat::DXT23,
+    PixelFormat::DXT23_SRGB, PixelFormat::DXT45,     PixelFormat::DXT45_SRGB,
+    PixelFormat::DXN2SNORM,  PixelFormat::BC7U,      PixelFormat::BC7U_SRGB,
+    PixelFormat::BC6H_SF16,  PixelFormat::BC6H_UF16,
+};
+// Missing formats:
+// PixelFormat::RGBA32I
+// COMPRESSED_RG_RGTC2
+
+constexpr std::array COPY_CLASS_64_BITS = {
+    PixelFormat::RGBA16F, PixelFormat::RG32F,   PixelFormat::RGBA16UI,  PixelFormat::RG32UI,
+    PixelFormat::RGBA16U, PixelFormat::RGBA16S, PixelFormat::DXT1_SRGB, PixelFormat::DXT1,
+
+};
+// Missing formats:
+// PixelFormat::RGBA16I
+// PixelFormat::RG32I,
+// COMPRESSED_RGB_S3TC_DXT1_EXT
+// COMPRESSED_SRGB_S3TC_DXT1_EXT
+// COMPRESSED_RGBA_S3TC_DXT1_EXT
+// COMPRESSED_SIGNED_RED_RGTC1
+
+void Enable(FormatCompatibility::Table& compatiblity, size_t format_a, size_t format_b) {
+    compatiblity[format_a][format_b] = true;
+    compatiblity[format_b][format_a] = true;
+}
+
+void Enable(FormatCompatibility::Table& compatibility, PixelFormat format_a, PixelFormat format_b) {
+    Enable(compatibility, static_cast<size_t>(format_a), static_cast<size_t>(format_b));
+}
+
+template <typename Range>
+void EnableRange(FormatCompatibility::Table& compatibility, const Range& range) {
+    for (auto it_a = range.begin(); it_a != range.end(); ++it_a) {
+        for (auto it_b = it_a; it_b != range.end(); ++it_b) {
+            Enable(*it_a, *it_b);
+        }
+    }
+}
+
+} // Anonymous namespace
+
+FormatCompatibility::FormatCompatibility() {
+    for (size_t i = 0; i < MaxPixelFormat; ++i) {
+        // Identity is allowed
+        Enable(view, i, i);
+    }
+
+    EnableRange(view, VIEW_CLASS_128_BITS);
+    EnableRange(view, VIEW_CLASS_96_BITS);
+    EnableRange(view, VIEW_CLASS_64_BITS);
+    EnableRange(view, VIEW_CLASS_32_BITS);
+    EnableRange(view, VIEW_CLASS_16_BITS);
+    EnableRange(view, VIEW_CLASS_8_BITS);
+    EnableRange(view, VIEW_CLASS_RGTC1_RED);
+    EnableRange(view, VIEW_CLASS_RGTC2_RG);
+    EnableRange(view, VIEW_CLASS_BPTC_UNORM);
+    EnableRange(view, VIEW_CLASS_BPTC_FLOAT);
+
+    copy = view;
+    EnableRange(copy, COPY_CLASS_128_BITS);
+    EnableRange(copy, COPY_CLASS_64_BITS);
+}
+
+} // namespace VideoCore::Surface

src/video_core/compatible_formats.h

@@ -0,0 +1,32 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <bitset>
+#include <cstddef>
+
+#include "video_core/surface.h"
+
+namespace VideoCore::Surface {
+
+class FormatCompatibility {
+public:
+    using Table = std::array<std::bitset<MaxPixelFormat>, MaxPixelFormat>;
+
+    explicit FormatCompatibility();
+
+    bool TestView(PixelFormat format_a, PixelFormat format_b) const noexcept {
+        return view[static_cast<size_t>(format_a)][static_cast<size_t>(format_b)];
+    }
+
+    bool TestCopy(PixelFormat format_a, PixelFormat format_b) const noexcept {
+        return copy[static_cast<size_t>(format_a)][static_cast<size_t>(format_b)];
+    }
+
+private:
+    Table view;
+    Table copy;
+};
+
+} // namespace VideoCore::Surface