Add F16, SkColorSpaceXform support to SkBmpCodec

BUG=skia:4895

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4390

Change-Id: I9cb727e7f13816b0ac882f62ec635a4528c3a524
Reviewed-on: https://skia-review.googlesource.com/4390
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 47 insertions, 16 deletions

diff --git a/src/codec/SkBmpRLECodec.cpp b/src/codec/SkBmpRLECodec.cpp
index 6e7bac9c6d..85b965e611 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) {
@@ -306,12 +302,6 @@ 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();
 
@@ -320,10 +310,6 @@ int SkBmpRLECodec::decodeRows(const SkImageInfo& info, void* dst, size_t dstRowB
 
     // 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);
     }
@@ -332,13 +318,58 @@ int SkBmpRLECodec::decodeRows(const SkImageInfo& info, void* dst, size_t dstRowB
     // 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;
+
+        dstInfo = dstInfo.makeWH(dstInfo.width(), height);
     } else {
         fLinesToSkip -= height;
         return height;
     }
 
+    void* decodeDst = dst;
+    size_t decodeRowBytes = dstRowBytes;
+    SkImageInfo decodeInfo = dstInfo;
+    if (decodeDst) {
+        if (this->colorXform()) {
+            decodeInfo = decodeInfo.makeColorType(kBGRA_8888_SkColorType);
+            if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
+                int count = height * dstInfo.width();
+                this->resetXformBuffer(count);
+                sk_bzero(this->xformBuffer(), count * sizeof(uint32_t));
+                decodeDst = this->xformBuffer();
+                decodeRowBytes = dstInfo.width() * sizeof(uint32_t);
+            }
+        }
+    }
+
+    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;