Add F16, SkColorSpaceXform support to SkBmpCodec

BUG=skia:4895

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4300

Change-Id: I2f2b8d3854ea3a8c5904dd3c5bea0342e2be9789
Reviewed-on: https://skia-review.googlesource.com/4300
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 57 insertions, 25 deletions

diff --git a/src/codec/SkBmpRLECodec.cpp b/src/codec/SkBmpRLECodec.cpp
index 33ba851ec6..e502fe879f 100644
--- a/src/codec/SkBmpRLECodec.cpp
+++ b/src/codec/SkBmpRLECodec.cpp
@@ -44,10 +44,6 @@ SkCodec::Result SkBmpRLECodec::onGetPixels(const SkImageInfo& dstInfo,
         // Subsets are not supported.
         return kUnimplemented;
     }
-    if (!conversion_possible_ignore_color_space(dstInfo, this->getInfo())) {
-        SkCodecPrintf("Error: cannot convert input type to output type.\n");
-        return kInvalidConversion;
-    }
 
     Result result = this->prepareToDecode(dstInfo, opts, inputColorPtr, inputColorCount);
     if (kSuccess != result) {
@@ -267,7 +263,7 @@ void SkBmpRLECodec::setRGBPixel(void* dst, size_t dstRowBytes,
     }
 }
 
-SkCodec::Result SkBmpRLECodec::prepareToDecode(const SkImageInfo& dstInfo,
+SkCodec::Result SkBmpRLECodec::onPrepareToDecode(const SkImageInfo& dstInfo,
         const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
     // FIXME: Support subsets for scanline decodes.
     if (options.fSubset) {
@@ -306,39 +302,75 @@ SkCodec::Result SkBmpRLECodec::prepareToDecode(const SkImageInfo& dstInfo,
  */
 int SkBmpRLECodec::decodeRows(const SkImageInfo& info, void* dst, size_t dstRowBytes,
         const Options& opts) {
-    // Set RLE flags
-    static const uint8_t RLE_ESCAPE = 0;
-    static const uint8_t RLE_EOL = 0;
-    static const uint8_t RLE_EOF = 1;
-    static const uint8_t RLE_DELTA = 2;
-
     const int width = this->getInfo().width();
     int height = info.height();
 
-    // Account for sampling.
-    SkImageInfo dstInfo = info.makeWH(get_scaled_dimension(width, fSampleX), height);
-
-    // Set the background as transparent.  Then, if the RLE code skips pixels,
-    // the skipped pixels will be transparent.
-    // Because of the need for transparent pixels, kN32 is the only color
-    // type that makes sense for the destination format.
-    SkASSERT(kRGBA_8888_SkColorType == dstInfo.colorType() ||
-            kBGRA_8888_SkColorType == dstInfo.colorType());
-    if (dst) {
-        SkSampler::Fill(dstInfo, dst, dstRowBytes, SK_ColorTRANSPARENT, opts.fZeroInitialized);
-    }
-
     // Adjust the height and the dst if the previous call to decodeRows() left us
     // with lines that need to be skipped.
     if (height > fLinesToSkip) {
         height -= fLinesToSkip;
-        dst = SkTAddOffset<void>(dst, fLinesToSkip * dstRowBytes);
+        if (dst) {
+            dst = SkTAddOffset<void>(dst, fLinesToSkip * dstRowBytes);
+        }
         fLinesToSkip = 0;
     } else {
         fLinesToSkip -= height;
         return height;
     }
 
+    // Account for sampling.
+    SkImageInfo dstInfo = info.makeWH(get_scaled_dimension(width, fSampleX), height);
+
+    void* decodeDst = dst;
+    size_t decodeRowBytes = dstRowBytes;
+    SkImageInfo decodeInfo = dstInfo;
+    if (decodeDst) {
+        SkCodec::ZeroInitialized zeroInit = opts.fZeroInitialized;
+        if (this->colorXform()) {
+            decodeInfo = decodeInfo.makeColorType(kBGRA_8888_SkColorType);
+            if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
+                int count = height * dstInfo.width();
+                this->resetXformBuffer(count);
+                decodeDst = this->xformBuffer();
+                decodeRowBytes = dstInfo.width() * sizeof(uint32_t);
+                zeroInit = SkCodec::kNo_ZeroInitialized;
+            }
+        }
+
+        // Set the background as transparent.  Then, if the RLE code skips pixels,
+        // the skipped pixels will be transparent.
+        // Because of the need for transparent pixels, kN32 is the only color
+        // type that makes sense for the destination format.
+        SkASSERT(kRGBA_8888_SkColorType == decodeInfo.colorType() ||
+                 kBGRA_8888_SkColorType == decodeInfo.colorType());
+        SkSampler::Fill(decodeInfo, decodeDst, decodeRowBytes, SK_ColorTRANSPARENT, zeroInit);
+    }
+
+    int decodedHeight = this->decodeRLE(decodeInfo, decodeDst, decodeRowBytes);
+    if (this->colorXform() && decodeDst) {
+        for (int y = 0; y < decodedHeight; y++) {
+            this->applyColorXform(dstInfo, dst, decodeDst);
+            decodeDst = SkTAddOffset<void>(decodeDst, decodeRowBytes);
+            dst = SkTAddOffset<void>(dst, dstRowBytes);
+        }
+    }
+
+    return decodedHeight;
+}
+
+int SkBmpRLECodec::decodeRLE(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes) {
+    // Use the original width to count the number of pixels in each row.
+    const int width = this->getInfo().width();
+
+    // This tells us the number of rows that we are meant to decode.
+    const int height = dstInfo.height();
+
+    // Set RLE flags
+    static const uint8_t RLE_ESCAPE = 0;
+    static const uint8_t RLE_EOL = 0;
+    static const uint8_t RLE_EOF = 1;
+    static const uint8_t RLE_DELTA = 2;
+
     // Destination parameters
     int x = 0;
     int y = 0;