Add F16 source to the linear pipelin.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1882893003

Review URL: https://codereview.chromium.org/1882893003

3 files changed, 67 insertions, 4 deletions

diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 3b90704084..5e66bf1959 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -227,7 +227,8 @@ static bool choose_linear_pipeline(const SkShader::ContextRec& rec, const SkImag
     //
     if (srcInfo.colorType() != kRGBA_8888_SkColorType
         && srcInfo.colorType() != kBGRA_8888_SkColorType
-        && srcInfo.colorType() != kIndex_8_SkColorType) {
+        && srcInfo.colorType() != kIndex_8_SkColorType
+        && srcInfo.colorType() != kRGBA_F16_SkColorType) {
         return false;
     }
 
@@ -280,7 +281,8 @@ SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,
         }
         if (info->fPixmap.colorType() != kRGBA_8888_SkColorType
             && info->fPixmap.colorType() != kBGRA_8888_SkColorType
-            && info->fPixmap.colorType() != kIndex_8_SkColorType) {
+            && info->fPixmap.colorType() != kIndex_8_SkColorType
+            && info->fPixmap.colorType() != kRGBA_F16_SkColorType) {
             return nullptr;
         }
         return new (storage) LinearPipelineContext(shader, rec, info);
diff --git a/src/core/SkLinearBitmapPipeline.cpp b/src/core/SkLinearBitmapPipeline.cpp
index cf69e974dd..415179a0b1 100644
--- a/src/core/SkLinearBitmapPipeline.cpp
+++ b/src/core/SkLinearBitmapPipeline.cpp
@@ -549,6 +549,9 @@ private:
     GeneralSampler<SourceStrategy, Next> fSampler;
 };
 
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Specialized Samplers
+
 // RGBA8888UnitRepeatSrc - A sampler that takes advantage of the fact the the src and destination
 // are the same format and do not need in transformations in pixel space. Therefore, there is no
 // need to convert them to HiFi pixel format.
@@ -651,6 +654,9 @@ static SkLinearBitmapPipeline::SampleProcessorInterface* choose_pixel_sampler_ba
                 sampleStage->initStage<Sampler<PixelIndex8LRGB, Blender>>(next, srcPixmap);
             }
             break;
+        case kRGBA_F16_SkColorType:
+            sampleStage->initStage<Sampler<PixelHalfLinear, Blender>>(next, srcPixmap);
+            break;
         default:
             SkFAIL("Not implemented. Unsupported src");
             break;
@@ -718,7 +724,7 @@ private:
     Sk4f fPostAlpha;
 };
 
-static SkLinearBitmapPipeline::BlendProcessorInterface* choose_blender(
+static SkLinearBitmapPipeline::BlendProcessorInterface* choose_blender_for_shading(
     SkAlphaType alphaType,
     float postAlpha,
     SkLinearBitmapPipeline::BlenderStage* blenderStage) {
@@ -730,6 +736,7 @@ static SkLinearBitmapPipeline::BlendProcessorInterface* choose_blender(
     }
     return blenderStage->get();
 }
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -768,7 +775,7 @@ SkLinearBitmapPipeline::SkLinearBitmapPipeline(
 
     // As the stages are built, the chooser function may skip a stage. For example, with the
     // identity matrix, the matrix stage is skipped, and the tilerStage is the first stage.
-    auto blenderStage = choose_blender(alphaType, postAlpha, &fBlenderStage);
+    auto blenderStage = choose_blender_for_shading(alphaType, postAlpha, &fBlenderStage);
     auto samplerStage = choose_pixel_sampler(blenderStage, filterQuality, srcPixmap, &fSampleStage);
     auto tilerStage   = choose_tiler(samplerStage, dimensions, xTile, yTile,
                                      filterQuality, dx, &fTileStage);
diff --git a/src/core/SkLinearBitmapPipeline_sample.h b/src/core/SkLinearBitmapPipeline_sample.h
index 7157ffc8ee..d436e39399 100644
--- a/src/core/SkLinearBitmapPipeline_sample.h
+++ b/src/core/SkLinearBitmapPipeline_sample.h
@@ -9,6 +9,7 @@
 #define SkLinearBitmapPipeline_sampler_DEFINED
 
 #include "SkFixed.h"
+#include "SkHalf.h"
 #include "SkLinearBitmapPipeline_core.h"
 #include <array>
 #include <tuple>
@@ -734,6 +735,59 @@ private:
 using PixelIndex8SRGB = PixelIndex8<kSRGB_SkColorProfileType>;
 using PixelIndex8LRGB = PixelIndex8<kLinear_SkColorProfileType>;
 
+class PixelHalfLinear {
+public:
+    PixelHalfLinear(int width, const uint64_t* src) : fSrc{src}, fWidth{width}{ }
+    PixelHalfLinear(const SkPixmap& srcPixmap)
+        : fSrc{srcPixmap.addr64()}
+        , fWidth{static_cast<int>(srcPixmap.rowBytes() / 8)} { }
+
+    void VECTORCALL getFewPixels(int n, Sk4s xs, Sk4s ys, Sk4f* px0, Sk4f* px1, Sk4f* px2) {
+        Sk4i XIs = SkNx_cast<int, SkScalar>(xs);
+        Sk4i YIs = SkNx_cast<int, SkScalar>(ys);
+        Sk4i bufferLoc = YIs * fWidth + XIs;
+        switch (n) {
+            case 3:
+                *px2 = this->getPixelAt(fSrc, bufferLoc[2]);
+            case 2:
+                *px1 = this->getPixelAt(fSrc, bufferLoc[1]);
+            case 1:
+                *px0 = this->getPixelAt(fSrc, bufferLoc[0]);
+            default:
+                break;
+        }
+    }
+
+    void VECTORCALL get4Pixels(Sk4s xs, Sk4s ys, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) {
+        Sk4i XIs = SkNx_cast<int, SkScalar>(xs);
+        Sk4i YIs = SkNx_cast<int, SkScalar>(ys);
+        Sk4i bufferLoc = YIs * fWidth + XIs;
+        *px0 = this->getPixelAt(fSrc, bufferLoc[0]);
+        *px1 = this->getPixelAt(fSrc, bufferLoc[1]);
+        *px2 = this->getPixelAt(fSrc, bufferLoc[2]);
+        *px3 = this->getPixelAt(fSrc, bufferLoc[3]);
+    }
+
+    void get4Pixels(const void* vsrc, int index, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) {
+        const uint32_t* src = static_cast<const uint32_t*>(vsrc);
+        *px0 = this->getPixelAt(src, index + 0);
+        *px1 = this->getPixelAt(src, index + 1);
+        *px2 = this->getPixelAt(src, index + 2);
+        *px3 = this->getPixelAt(src, index + 3);
+    }
+
+    Sk4f getPixelAt(const void* vsrc, int index) {
+        const uint64_t* src = static_cast<const uint64_t*>(vsrc);
+        return SkHalfToFloat_01(*src);
+    }
+
+    const void* row(int y) { return fSrc + y * fWidth[0]; }
+
+private:
+    const uint64_t* const fSrc;
+    const Sk4i            fWidth;
+};
+
 }  // namespace
 
 #endif  // SkLinearBitmapPipeline_sampler_DEFINED