From 1b830f9c82aa4801b8f2a8ea58b015d667484f4a Mon Sep 17 00:00:00 2001
From: Chinmay Garde <chinmaygarde@google.com>
Date: Thu, 15 Jul 2021 12:31:31 -0700
Subject: [PATCH] Wire up texture usage.

---
 engine/src/flutter/impeller/compositor/BUILD.gn     |  2 +-
 engine/src/flutter/impeller/compositor/formats.h    |  9 +++++++++
 .../flutter/impeller/compositor/formats_metal.mm    | 13 +++++++++++++
 .../impeller/compositor/texture_descriptor.h        |  2 ++
 engine/src/flutter/impeller/playground/BUILD.gn     |  2 +-
 5 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/engine/src/flutter/impeller/compositor/BUILD.gn b/engine/src/flutter/impeller/compositor/BUILD.gn
index 1b15d184f31..0a9c708e14d 100644
--- a/engine/src/flutter/impeller/compositor/BUILD.gn
+++ b/engine/src/flutter/impeller/compositor/BUILD.gn
@@ -73,7 +73,7 @@ impeller_component("compositor") {
     "../shader_glue",
   ]
 
-  libs = [ "Metal.framework" ]
+  frameworks = [ "Metal.framework" ]
 }
 
 source_set("compositor_unittests") {
diff --git a/engine/src/flutter/impeller/compositor/formats.h b/engine/src/flutter/impeller/compositor/formats.h
index 711d1684565..6de3d173be7 100644
--- a/engine/src/flutter/impeller/compositor/formats.h
+++ b/engine/src/flutter/impeller/compositor/formats.h
@@ -59,6 +59,15 @@ enum class StoreAction {
   kStore,
 };
 
+using TextureUsageMask = uint64_t;
+
+enum class TextureUsage : TextureUsageMask {
+  kUnknown,
+  kShaderRead,
+  kShaderWrite,
+  kRenderTarget,
+};
+
 enum class PrimitiveType {
   kTriangle,
   kTriangleStrip,
diff --git a/engine/src/flutter/impeller/compositor/formats_metal.mm b/engine/src/flutter/impeller/compositor/formats_metal.mm
index cef3c06ba67..d0bffb5b79f 100644
--- a/engine/src/flutter/impeller/compositor/formats_metal.mm
+++ b/engine/src/flutter/impeller/compositor/formats_metal.mm
@@ -83,6 +83,19 @@ MTLTextureDescriptor* ToMTLTextureDescriptor(const TextureDescriptor& desc) {
   mtl_desc.width = desc.size.width;
   mtl_desc.height = desc.size.height;
   mtl_desc.mipmapLevelCount = desc.mip_count;
+  mtl_desc.usage = MTLTextureUsageUnknown;
+  if (desc.usage & static_cast<TextureUsageMask>(TextureUsage::kUnknown)) {
+    mtl_desc.usage |= MTLTextureUsageUnknown;
+  }
+  if (desc.usage & static_cast<TextureUsageMask>(TextureUsage::kShaderRead)) {
+    mtl_desc.usage |= MTLTextureUsageShaderRead;
+  }
+  if (desc.usage & static_cast<TextureUsageMask>(TextureUsage::kShaderWrite)) {
+    mtl_desc.usage |= MTLTextureUsageShaderWrite;
+  }
+  if (desc.usage & static_cast<TextureUsageMask>(TextureUsage::kRenderTarget)) {
+    mtl_desc.usage |= MTLTextureUsageRenderTarget;
+  }
   return mtl_desc;
 }
 
diff --git a/engine/src/flutter/impeller/compositor/texture_descriptor.h b/engine/src/flutter/impeller/compositor/texture_descriptor.h
index 07e52ca645b..fc647cbbb93 100644
--- a/engine/src/flutter/impeller/compositor/texture_descriptor.h
+++ b/engine/src/flutter/impeller/compositor/texture_descriptor.h
@@ -16,6 +16,8 @@ struct TextureDescriptor {
   PixelFormat format = PixelFormat::kUnknown;
   ISize size;
   size_t mip_count = 1u;  // Size::MipCount is usually appropriate.
+  TextureUsageMask usage =
+      static_cast<TextureUsageMask>(TextureUsage::kShaderRead);
 
   constexpr size_t GetSizeOfBaseMipLevel() const {
     if (!IsValid()) {
diff --git a/engine/src/flutter/impeller/playground/BUILD.gn b/engine/src/flutter/impeller/playground/BUILD.gn
index 0a912bef5d8..5c142a125c8 100644
--- a/engine/src/flutter/impeller/playground/BUILD.gn
+++ b/engine/src/flutter/impeller/playground/BUILD.gn
@@ -20,7 +20,7 @@ impeller_component("playground") {
   ]
 
   if (is_mac) {
-    libs = [
+    frameworks = [
       "AppKit.framework",
       "QuartzCore.framework",
     ]