Metal: Allow unswizzled BC1 RGB

scripts/code_generation_hashes/Metal_format_table.json

@@ -6,7 +6,7 @@
   "src/libANGLE/renderer/metal/gen_mtl_format_table.py":
     "60bf684695cd552e85fc11eba2a1d5bc",
   "src/libANGLE/renderer/metal/mtl_format_map.json":
-    "bd60f72f1dc35054ce439c3edad1caab",
+    "22b62b3705e53c5a6ecf5a173f2e7dc9",
   "src/libANGLE/renderer/metal/mtl_format_table_autogen.mm":
-    "1d962a58e82ce1288470e9e0ba3d688b"
+    "e47df76e259be3e039541b9615b35a32"
 }
\ No newline at end of file

src/libANGLE/renderer/metal/mtl_format_map.json

@@ -184,11 +184,11 @@
             "R5G5B5A1_UNORM": "R8G8B8A8_UNORM",
             "R4G4B4A4_UNORM": "R8G8B8A8_UNORM",
             "BC1_RGB_UNORM_BLOCK": {
-                "default": "NONE",
+                "default": "BC1_RGBA_UNORM_BLOCK",
                 "swizzle": ["RGB1", "BC1_RGBA_UNORM_BLOCK"]
             },
             "BC1_RGB_UNORM_SRGB_BLOCK": {
-                "default": "NONE",
+                "default": "BC1_RGBA_UNORM_SRGB_BLOCK",
                 "swizzle": ["RGB1", "BC1_RGBA_UNORM_SRGB_BLOCK"]
             },
             "ETC1_R8G8B8_UNORM_BLOCK": "R8G8B8A8_UNORM",

src/libANGLE/renderer/metal/mtl_format_table_autogen.mm

@@ -859,8 +859,8 @@ void Format::init(const DisplayMtl *display, angle::FormatID intendedFormatId_)
 #    endif  // #if defined(__IPHONE_13_0) || defined(__MAC_10_15)
             {
 
-                this->metalFormat    = MTLPixelFormatInvalid;
-                this->actualFormatId = angle::FormatID::NONE;
+                this->metalFormat    = MTLPixelFormatBC1_RGBA;
+                this->actualFormatId = angle::FormatID::BC1_RGBA_UNORM_BLOCK;
                 this->initFunction   = nullptr;
 
                 this->swizzled = false;
@@ -883,8 +883,8 @@ void Format::init(const DisplayMtl *display, angle::FormatID intendedFormatId_)
 #    endif  // #if defined(__IPHONE_13_0) || defined(__MAC_10_15)
             {
 
-                this->metalFormat    = MTLPixelFormatInvalid;
-                this->actualFormatId = angle::FormatID::NONE;
+                this->metalFormat    = MTLPixelFormatBC1_RGBA_sRGB;
+                this->actualFormatId = angle::FormatID::BC1_RGBA_UNORM_SRGB_BLOCK;
                 this->initFunction   = nullptr;
 
                 this->swizzled = false;

src/libANGLE/renderer/metal/mtl_format_utils.mm

@@ -144,8 +144,8 @@ bool Format::needConversion(angle::FormatID srcFormatId) const
         (srcFormatId == angle::FormatID::BC1_RGB_UNORM_SRGB_BLOCK &&
          actualFormatId == angle::FormatID::BC1_RGBA_UNORM_SRGB_BLOCK))
     {
-        // DXT1 RGB format already swizzled with alpha=1, so no need to convert
-        ASSERT(swizzled);
+        // When texture swizzling is available, DXT1 RGB format will be swizzled with RGB1.
+        // WebGL allows unswizzled mapping when swizzling is not available. No need to convert.
         return false;
     }
     if (srcFormatId == angle::FormatID::ETC1_R8G8B8_UNORM_BLOCK &&

src/tests/gl_tests/DXT1CompressedTextureTest.cpp

@@ -115,8 +115,13 @@ TEST_P(DXT1CompressedTextureTest, DXT1Alpha)
 {
     ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_EXT_texture_compression_dxt1"));
 
-    // http://anglebug.com/4917
-    ANGLE_SKIP_TEST_IF(IsD3D());
+    // On Intel Metal, results would depend on the GPU Family.
+    ANGLE_SKIP_TEST_IF(IsMetal() && IsIntel());
+
+    // On platforms without native support for DXT1 RGB or texture swizzling (such as D3D or some
+    // Metal configurations), this test is allowed to succeed with transparent black instead of
+    // opaque black.
+    const bool opaque = !IsD3D() && !(IsMetal() && !IsMetalTextureSwizzleAvailable());
 
     GLTexture texture;
     glBindTexture(GL_TEXTURE_2D, texture);
@@ -125,7 +130,7 @@ TEST_P(DXT1CompressedTextureTest, DXT1Alpha)
 
     // Image using pixels with the code for transparent black:
     //          "BLACK,             if color0 <= color1 and code(x,y) == 3"
-    constexpr uint8_t CompressedImageDXT1[] = {0, 0, 0, 0, 51, 204, 51, 204};
+    constexpr uint8_t CompressedImageDXT1[] = {0, 0, 0, 0, 255, 255, 255, 255};
     glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0,
                            sizeof(CompressedImageDXT1), CompressedImageDXT1);
 
@@ -146,7 +151,7 @@ TEST_P(DXT1CompressedTextureTest, DXT1Alpha)
     {
         for (GLint x = 0; x < kDrawSize; x++)
         {
-            EXPECT_PIXEL_EQ(x, y, 0, 0, 0, 255) << "at (" << x << ", " << y << ")";
+            EXPECT_PIXEL_EQ(x, y, 0, 0, 0, opaque ? 255 : 0) << "at (" << x << ", " << y << ")";
         }
     }
 }

src/tests/test_utils/angle_test_instantiate_apple.mm

@@ -31,9 +31,9 @@ bool IsMetalTextureSwizzleAvailable()
     // hardwares, however, it is OK for testing.
     if (ANGLE_APPLE_AVAILABLE_XCI(10.15, 13.0, 13))
     {
-        // Intel doesn't support swizzle because it is GPU family 1. We don't have a way to detect
-        // Metal family here, so skip on Intel.
-        return !IsIntel();
+        // All NVIDIA and older Intel don't support swizzle because they are GPU family 1.
+        // We don't have a way to detect Metal family here, so skip all Intel for now.
+        return !IsIntel() && !IsNVIDIA();
     }
     return false;
 }