1 files changed, 129 insertions, 0 deletions
diff --git a/src/video_core/texture_cache/decode_bc.cpp b/src/video_core/texture_cache/decode_bc.cpp
new file mode 100644
index 000000000..3e26474a3
--- /dev/null
+++ b/src/video_core/texture_cache/decode_bc.cpp
@@ -0,0 +1,129 @@
+// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <algorithm>
+#include <array>
+#include <span>
+#include <bc_decoder.h>
+
+#include "common/common_types.h"
+#include "video_core/texture_cache/decode_bc.h"
+
+namespace VideoCommon {
+
+namespace {
+constexpr u32 BLOCK_SIZE = 4;
+
+using VideoCore::Surface::PixelFormat;
+
+constexpr bool IsSigned(PixelFormat pixel_format) {
+    switch (pixel_format) {
+    case PixelFormat::BC4_SNORM:
+    case PixelFormat::BC4_UNORM:
+    case PixelFormat::BC5_SNORM:
+    case PixelFormat::BC5_UNORM:
+    case PixelFormat::BC6H_SFLOAT:
+    case PixelFormat::BC6H_UFLOAT:
+        return true;
+    default:
+        return false;
+    }
+}
+
+constexpr u32 BlockSize(PixelFormat pixel_format) {
+    switch (pixel_format) {
+    case PixelFormat::BC1_RGBA_SRGB:
+    case PixelFormat::BC1_RGBA_UNORM:
+    case PixelFormat::BC4_SNORM:
+    case PixelFormat::BC4_UNORM:
+        return 8;
+    default:
+        return 16;
+    }
+}
+} // Anonymous namespace
+
+u32 ConvertedBytesPerBlock(VideoCore::Surface::PixelFormat pixel_format) {
+    switch (pixel_format) {
+    case PixelFormat::BC4_SNORM:
+    case PixelFormat::BC4_UNORM:
+        return 1;
+    case PixelFormat::BC5_SNORM:
+    case PixelFormat::BC5_UNORM:
+        return 2;
+    case PixelFormat::BC6H_SFLOAT:
+    case PixelFormat::BC6H_UFLOAT:
+        return 8;
+    default:
+        return 4;
+    }
+}
+
+template <auto decompress, PixelFormat pixel_format>
+void DecompressBlocks(std::span<const u8> input, std::span<u8> output, Extent3D extent,
+                      bool is_signed = false) {
+    const u32 out_bpp = ConvertedBytesPerBlock(pixel_format);
+    const u32 block_width = std::min(extent.width, BLOCK_SIZE);
+    const u32 block_height = std::min(extent.height, BLOCK_SIZE);
+    const u32 pitch = extent.width * out_bpp;
+    size_t input_offset = 0;
+    size_t output_offset = 0;
+    for (u32 slice = 0; slice < extent.depth; ++slice) {
+        for (u32 y = 0; y < extent.height; y += block_height) {
+            size_t row_offset = 0;
+            for (u32 x = 0; x < extent.width;
+                 x += block_width, row_offset += block_width * out_bpp) {
+                const u8* src = input.data() + input_offset;
+                u8* const dst = output.data() + output_offset + row_offset;
+                if constexpr (IsSigned(pixel_format)) {
+                    decompress(src, dst, x, y, extent.width, extent.height, is_signed);
+                } else {
+                    decompress(src, dst, x, y, extent.width, extent.height);
+                }
+                input_offset += BlockSize(pixel_format);
+            }
+            output_offset += block_height * pitch;
+        }
+    }
+}
+
+void DecompressBCn(std::span<const u8> input, std::span<u8> output, Extent3D extent,
+                   VideoCore::Surface::PixelFormat pixel_format) {
+    switch (pixel_format) {
+    case PixelFormat::BC1_RGBA_UNORM:
+    case PixelFormat::BC1_RGBA_SRGB:
+        DecompressBlocks<bcn::DecodeBc1, PixelFormat::BC1_RGBA_UNORM>(input, output, extent);
+        break;
+    case PixelFormat::BC2_UNORM:
+    case PixelFormat::BC2_SRGB:
+        DecompressBlocks<bcn::DecodeBc2, PixelFormat::BC2_UNORM>(input, output, extent);
+        break;
+    case PixelFormat::BC3_UNORM:
+    case PixelFormat::BC3_SRGB:
+        DecompressBlocks<bcn::DecodeBc3, PixelFormat::BC3_UNORM>(input, output, extent);
+        break;
+    case PixelFormat::BC4_SNORM:
+    case PixelFormat::BC4_UNORM:
+        DecompressBlocks<bcn::DecodeBc4, PixelFormat::BC4_UNORM>(
+            input, output, extent, pixel_format == PixelFormat::BC4_SNORM);
+        break;
+    case PixelFormat::BC5_SNORM:
+    case PixelFormat::BC5_UNORM:
+        DecompressBlocks<bcn::DecodeBc5, PixelFormat::BC5_UNORM>(
+            input, output, extent, pixel_format == PixelFormat::BC5_SNORM);
+        break;
+    case PixelFormat::BC6H_SFLOAT:
+    case PixelFormat::BC6H_UFLOAT:
+        DecompressBlocks<bcn::DecodeBc6, PixelFormat::BC6H_UFLOAT>(
+            input, output, extent, pixel_format == PixelFormat::BC6H_SFLOAT);
+        break;
+    case PixelFormat::BC7_SRGB:
+    case PixelFormat::BC7_UNORM:
+        DecompressBlocks<bcn::DecodeBc7, PixelFormat::BC7_UNORM>(input, output, extent);
+        break;
+    default:
+        LOG_WARNING(HW_GPU, "Unimplemented BCn decompression {}", pixel_format);
+    }
+}
+
+} // namespace VideoCommon