Revert "Add SkImage::makeColorSpace() with correct transfer fn behavior"

This reverts commit 9ad0531a18f854e5a2c8034880140dd6cd3ea3c1.

Reason for revert: Does not handle transfer fn behavior.

Original change's description:
> Add SkImage::makeColorSpace() with correct transfer fn behavior
> 
> Completes implementation for lazy and raster images.  gpu is
> still a TODO.
> 
> Bug: skia:6553
> Change-Id: I04eea5c4fb53c50c0406c2e6b6778b0e21fd85f8
> Reviewed-on: https://skia-review.googlesource.com/14403
> Commit-Queue: Matt Sarett <msarett@google.com>
> Reviewed-by: Mike Reed <reed@google.com>
> 

TBR=mtklein@google.com,msarett@google.com,brianosman@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I3830321aea7d0dc5ab38a40f3318bb53a41df383
Reviewed-on: https://skia-review.googlesource.com/15306
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 54 insertions, 8 deletions

diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index 1c3c515a60..88847551d1 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -112,8 +112,7 @@ public:
         SkASSERT(bitmapMayBeMutable || fBitmap.isImmutable());
     }
 
-    sk_sp<SkImage> onMakeColorSpace(sk_sp<SkColorSpace>, SkColorType,
-                                    SkTransferFunctionBehavior) const override;
+    sk_sp<SkImage> onMakeColorSpace(sk_sp<SkColorSpace>) const override;
 
 #if SK_SUPPORT_GPU
     sk_sp<GrTextureProxy> refPinnedTextureProxy(uint32_t* uniqueID) const override;
@@ -343,22 +342,69 @@ bool SkImage_Raster::onAsLegacyBitmap(SkBitmap* bitmap, LegacyBitmapMode mode) c
 
 ///////////////////////////////////////////////////////////////////////////////
 
-sk_sp<SkImage> SkImage_Raster::onMakeColorSpace(sk_sp<SkColorSpace> target,
-                                                SkColorType targetColorType,
-                                                SkTransferFunctionBehavior premulBehavior) const {
-    SkImageInfo dstInfo = fBitmap.info().makeColorType(targetColorType).makeColorSpace(target);
+static inline void do_color_xform_non_linear_blending(SkBitmap* dst, const SkPixmap& src) {
+    SkDEBUGCODE(SkColorSpaceTransferFn fn;);
+    SkASSERT(dst->colorSpace()->isNumericalTransferFn(&fn) &&
+             src.colorSpace()->isNumericalTransferFn(&fn));
+
+    void* dstPixels = dst->getPixels();
+    const void* srcPixels = src.addr();
+    size_t dstRowBytes = dst->rowBytes();
+    size_t srcRowBytes = src.rowBytes();
+    if (kN32_SkColorType != src.colorType()) {
+        SkAssertResult(src.readPixels(src.info().makeColorType(kN32_SkColorType), dstPixels,
+                                      dstRowBytes, 0, 0));
+
+        srcPixels = dstPixels;
+        srcRowBytes = dstRowBytes;
+    }
+
+    std::unique_ptr<SkColorSpaceXform> xform = SkColorSpaceXform_Base::New(
+            src.colorSpace(), dst->colorSpace(), SkTransferFunctionBehavior::kIgnore);
+
+    void* dstRow = dstPixels;
+    const void* srcRow = srcPixels;
+    for (int y = 0; y < dst->height(); y++) {
+        // This function assumes non-linear blending.  Which means that we must start by
+        // unpremultiplying in the gamma encoded space.
+        const void* tmpRow = srcRow;
+        if (kPremul_SkAlphaType == src.alphaType()) {
+            SkUnpremultiplyRow<false>((uint32_t*) dstRow, (const uint32_t*) srcRow, dst->width());
+            tmpRow = dstRow;
+        }
+
+        SkColorSpaceXform::ColorFormat fmt = select_xform_format(kN32_SkColorType);
+        SkAssertResult(xform->apply(fmt, dstRow, fmt, tmpRow, dst->width(), dst->alphaType()));
+
+        dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
+        srcRow = SkTAddOffset<const void>(srcRow, srcRowBytes);
+    }
+}
+
+sk_sp<SkImage> SkImage_Raster::onMakeColorSpace(sk_sp<SkColorSpace> target) const {
+    // Force the color type of the new image to be kN32_SkColorType.
+    // (1) This means we lose precision on F16 images.  This is necessary while this function is
+    //     used to pre-transform inputs to a legacy canvas.  Legacy canvases do not handle F16.
+    // (2) kIndex8 and kGray8 must be expanded in order perform a color space transformation.
+    // (3) Seems reasonable to expand k565 and k4444.  It's nice to avoid these color types for
+    //     clients who opt into color space support.
+    SkImageInfo dstInfo = fBitmap.info().makeColorType(kN32_SkColorType).makeColorSpace(target);
     SkBitmap dst;
     dst.allocPixels(dstInfo);
 
     SkPixmap src;
-    SkAssertResult(fBitmap.peekPixels(&src));
+    SkTLazy<SkBitmap> tmp;
+    if (!fBitmap.peekPixels(&src)) {
+        tmp.init(fBitmap);
+        SkAssertResult(tmp.get()->peekPixels(&src));
+    }
 
     // Treat nullptr srcs as sRGB.
     if (!src.colorSpace()) {
         src.setColorSpace(SkColorSpace::MakeSRGB());
     }
 
-    SkAssertResult(dst.writePixels(src));
+    do_color_xform_non_linear_blending(&dst, src);
     dst.setImmutable();
     return SkImage::MakeFromBitmap(dst);
 }