Add private grpixelconfigs for alpha_8 and alpha_half

Bug: skia:
Change-Id: I5191b6e045aea2a5af2b305b5972ad1e638a7ace
Reviewed-on: https://skia-review.googlesource.com/71763
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>

2 files changed, 12 insertions, 3 deletions

diff --git a/src/gpu/vk/GrVkCaps.cpp b/src/gpu/vk/GrVkCaps.cpp
index 2b24205af8..6804aeb22f 100644
--- a/src/gpu/vk/GrVkCaps.cpp
+++ b/src/gpu/vk/GrVkCaps.cpp
@@ -208,7 +208,10 @@ void GrVkCaps::initShaderCaps(const VkPhysicalDeviceProperties& properties, uint
     // fConfigOutputSwizzle will default to RGBA so we only need to set it for alpha only config.
     for (int i = 0; i < kGrPixelConfigCnt; ++i) {
         GrPixelConfig config = static_cast<GrPixelConfig>(i);
-        if (GrPixelConfigIsAlphaOnly(config)) {
+        // Vulkan doesn't support a single channel format stored in alpha.
+        if (GrPixelConfigIsAlphaOnly(config) &&
+            kAlpha_8_as_Alpha_GrPixelConfig != config &&
+            kAlpha_half_as_Alpha_GrPixelConfig != config) {
             shaderCaps->fConfigTextureSwizzle[i] = GrSwizzle::RRRR();
             shaderCaps->fConfigOutputSwizzle[i] = GrSwizzle::AAAA();
         } else {
diff --git a/src/gpu/vk/GrVkUtil.cpp b/src/gpu/vk/GrVkUtil.cpp
index 0ce47cb962..729804bd32 100644
--- a/src/gpu/vk/GrVkUtil.cpp
+++ b/src/gpu/vk/GrVkUtil.cpp
@@ -42,9 +42,12 @@ bool GrPixelConfigToVkFormat(GrPixelConfig config, VkFormat* format) {
             // store the data is if it was B4G4R4A4 and swizzle in shaders
             *format = VK_FORMAT_B4G4R4A4_UNORM_PACK16;
             return true;
-        case kAlpha_8_GrPixelConfig:
+        case kAlpha_8_GrPixelConfig: // fall through
+        case kAlpha_8_as_Red_GrPixelConfig:
             *format = VK_FORMAT_R8_UNORM;
             return true;
+        case kAlpha_8_as_Alpha_GrPixelConfig:
+            return false;
         case kGray_8_GrPixelConfig:
             *format = VK_FORMAT_R8_UNORM;
             return true;
@@ -57,9 +60,12 @@ bool GrPixelConfigToVkFormat(GrPixelConfig config, VkFormat* format) {
         case kRGBA_half_GrPixelConfig:
             *format = VK_FORMAT_R16G16B16A16_SFLOAT;
             return true;
-        case kAlpha_half_GrPixelConfig:
+        case kAlpha_half_GrPixelConfig: // fall through
+        case kAlpha_half_as_Red_GrPixelConfig:
             *format = VK_FORMAT_R16_SFLOAT;
             return true;
+        case kAlpha_half_as_Alpha_GrPixelConfig:
+            return false;
     }
     SK_ABORT("Unexpected config");
     return false;