apply codec origin in generator

Bug: skia:
Change-Id: I383dacb49b1e3c88467ccdbf3288764bb1bbf01a
Reviewed-on: https://skia-review.googlesource.com/58600
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Mike Reed <reed@google.com>

3 files changed, 180 insertions, 9 deletions

diff --git a/src/codec/SkCodecImageGenerator.cpp b/src/codec/SkCodecImageGenerator.cpp
index e6ca2122ea..e8d7d3038a 100644
--- a/src/codec/SkCodecImageGenerator.cpp
+++ b/src/codec/SkCodecImageGenerator.cpp
@@ -5,8 +5,41 @@
  * found in the LICENSE file.
  */
 
+#include "SkAutoPixmapStorage.h"
 #include "SkCodecImageGenerator.h"
 #include "SkMakeUnique.h"
+#include "SkPixmapPriv.h"
+
+#define kMirrorX    SkPixmapPriv::kMirrorX
+#define kMirrorY    SkPixmapPriv::kMirrorY
+#define kSwapXY     SkPixmapPriv::kSwapXY
+
+const uint8_t gOrientationFlags[] = {
+    0,                              // kTopLeft_Origin
+    kMirrorX,                       // kTopRight_Origin
+    kMirrorX | kMirrorY,            // kBottomRight_Origin
+               kMirrorY,            // kBottomLeft_Origin
+                          kSwapXY,  // kLeftTop_Origin
+    kMirrorX            | kSwapXY,  // kRightTop_Origin
+    kMirrorX | kMirrorY | kSwapXY,  // kRightBottom_Origin
+               kMirrorY | kSwapXY,  // kLeftBottom_Origin
+};
+
+SkPixmapPriv::OrientFlags SkPixmapPriv::OriginToOrient(SkCodec::Origin o) {
+    unsigned io = static_cast<int>(o) - 1;
+    SkASSERT(io < SK_ARRAY_COUNT(gOrientationFlags));
+    return static_cast<SkPixmapPriv::OrientFlags>(gOrientationFlags[io]);
+}
+
+static bool should_swap_width_height(SkCodec::Origin o) {
+    return SkToBool(SkPixmapPriv::OriginToOrient(o) & kSwapXY);
+}
+
+static SkImageInfo swap_width_height(SkImageInfo info) {
+    return info.makeWH(info.height(), info.width());
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
 
 std::unique_ptr<SkImageGenerator> SkCodecImageGenerator::MakeFromEncodedCodec(sk_sp<SkData> data) {
     auto codec = SkCodec::MakeFromData(data);
@@ -17,16 +50,19 @@ std::unique_ptr<SkImageGenerator> SkCodecImageGenerator::MakeFromEncodedCodec(sk
     return std::unique_ptr<SkImageGenerator>(new SkCodecImageGenerator(std::move(codec), data));
 }
 
-static SkImageInfo adjust_info(const SkImageInfo& info) {
-    SkImageInfo newInfo = info;
+static SkImageInfo adjust_info(SkCodec* codec) {
+    SkImageInfo info = codec->getInfo();
     if (kUnpremul_SkAlphaType == info.alphaType()) {
-        newInfo = newInfo.makeAlphaType(kPremul_SkAlphaType);
+        info = info.makeAlphaType(kPremul_SkAlphaType);
     }
-    return newInfo;
+    if (should_swap_width_height(codec->getOrigin())) {
+        info = swap_width_height(info);
+    }
+    return info;
 }
 
 SkCodecImageGenerator::SkCodecImageGenerator(std::unique_ptr<SkCodec> codec, sk_sp<SkData> data)
-    : INHERITED(adjust_info(codec->getInfo()))
+    : INHERITED(adjust_info(codec.get()))
     , fCodec(std::move(codec))
     , fData(std::move(data))
 {}
@@ -35,13 +71,35 @@ SkData* SkCodecImageGenerator::onRefEncodedData() {
     return SkRef(fData.get());
 }
 
-bool SkCodecImageGenerator::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
-                                        const Options& opts) {
+bool SkCodecImageGenerator::onGetPixels(const SkImageInfo& requestInfo, void* requestPixels,
+                                        size_t requestRowBytes, const Options& opts) {
+    const SkCodec::Origin origin = fCodec->getOrigin();
+    const SkPixmap request(requestInfo, requestPixels, requestRowBytes);
+    const SkPixmap* codecMap = &request;
+    SkAutoPixmapStorage storage;    // used if we have to post-orient the output from the codec
+
+    if (origin != SkCodec::kTopLeft_Origin) {
+        SkImageInfo info = requestInfo;
+        if (should_swap_width_height(origin)) {
+            info = swap_width_height(info);
+        }
+        // need a tmp buffer to receive the pixels, so we can post-orient them
+        if (!storage.tryAlloc(info)) {
+            return false;
+        }
+        codecMap = &storage;
+    }
+
     SkCodec::Options codecOpts;
     codecOpts.fPremulBehavior = opts.fBehavior;
-    SkCodec::Result result = fCodec->getPixels(info, pixels, rowBytes, &codecOpts);
+    SkCodec::Result result = fCodec->getPixels(*codecMap, &codecOpts);
     switch (result) {
         case SkCodec::kSuccess:
+            if (codecMap != &request) {
+                return SkPixmapPriv::Orient(request, *codecMap,
+                                            SkPixmapPriv::OriginToOrient(origin));
+            }
+            // fall through
         case SkCodec::kIncompleteInput:
         case SkCodec::kErrorInInput:
             return true;
diff --git a/src/core/SkPixmap.cpp b/src/core/SkPixmap.cpp
index 1cee0a9d02..7ce97d23f2 100644
--- a/src/core/SkPixmap.cpp
+++ b/src/core/SkPixmap.cpp
@@ -15,9 +15,10 @@
 #include "SkMask.h"
 #include "SkNx.h"
 #include "SkPM4f.h"
-#include "SkPixmap.h"
+#include "SkPixmapPriv.h"
 #include "SkReadPixelsRec.h"
 #include "SkSurface.h"
+#include "SkTemplates.h"
 #include "SkUtils.h"
 
 /////////////////////////////////////////////////////////////////////////////////////////////////
@@ -381,3 +382,82 @@ bool SkPixmap::computeIsOpaque() const {
     }
     return false;
 }
+
+//////////////////////////////////////////////////////////////////////////////////////////////////
+
+template <typename T, typename F>
+void apply(const SkPixmap& dst, const SkPixmap& src, unsigned flags, F getAddr) {
+    const int maxX = dst.width() - 1;
+    const int maxY = dst.height() - 1;
+    T* dstRow = (T*)dst.writable_addr();
+    for (int dy = 0; dy < dst.height(); ++dy) {
+        for (int dx = 0; dx < dst.width(); ++dx) {
+            int sx = dx;
+            int sy = dy;
+            if (flags & SkPixmapPriv::kMirrorX) {
+                sx = maxX - sx;
+            }
+            if (flags & SkPixmapPriv::kMirrorY) {
+                sy = maxY - sy;
+            }
+            if (flags & SkPixmapPriv::kSwapXY) {
+                SkTSwap<int>(sx, sy);
+            }
+            dstRow[dx] = getAddr(src, sx, sy);
+        }
+        dstRow = SkTAddOffset<T>(dstRow, dst.rowBytes());
+    }
+}
+
+static bool apply_orientation(const SkPixmap& dst, const SkPixmap& src, unsigned flags) {
+    SkASSERT(dst.colorType() == src.colorType());
+
+    switch (dst.info().bytesPerPixel()) {
+        case 1:
+            apply<uint8_t>(dst, src, flags, [](const SkPixmap& pm, int x, int y) {
+                return *pm.addr8(x, y);
+            }); break;
+        case 2:
+            apply<uint16_t>(dst, src, flags, [](const SkPixmap& pm, int x, int y) {
+                return *pm.addr16(x, y);
+            }); break;
+        case 4:
+            apply<uint32_t>(dst, src, flags, [](const SkPixmap& pm, int x, int y) {
+                return *pm.addr32(x, y);
+            }); break;
+        case 8:
+            apply<uint64_t>(dst, src, flags, [](const SkPixmap& pm, int x, int y) {
+                return *pm.addr64(x, y);
+            }); break;
+        default:
+            return false;
+    }
+    return true;
+}
+
+bool SkPixmapPriv::Orient(const SkPixmap& dst, const SkPixmap& src, OrientFlags flags) {
+    SkASSERT((flags & ~(kMirrorX | kMirrorY | kSwapXY)) == 0);
+    if (src.colorType() != dst.colorType()) {
+        return false;
+    }
+    // note: we just ignore alphaType and colorSpace for this transformation
+
+    int w = src.width();
+    int h = src.height();
+    if (flags & kSwapXY) {
+        SkTSwap(w, h);
+    }
+    if (dst.width() != w || dst.height() != h) {
+        return false;
+    }
+    if (w == 0 || h == 0) {
+        return true;
+    }
+
+    // check for aliasing to self
+    if (src.addr() == dst.addr()) {
+        return flags == 0;
+    }
+    return apply_orientation(dst, src, flags);
+}
+
diff --git a/src/core/SkPixmapPriv.h b/src/core/SkPixmapPriv.h
new file mode 100644
index 0000000000..dfc9ce2dd0
--- /dev/null
+++ b/src/core/SkPixmapPriv.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkPixmapPriv_DEFINED
+#define SkPixmapPriv_DEFINED
+
+#include "SkPixmap.h"
+#include "SkCodec.h"
+
+class SkPixmapPriv {
+public:
+    // These flag are applied in this order (swap is applied last)
+    enum OrientFlags {
+        kMirrorX = 1 << 0,
+        kMirrorY = 1 << 1,
+        kSwapXY  = 1 << 2,
+    };
+
+    static OrientFlags OriginToOrient(SkCodec::Origin);
+
+    /**
+     *  Copy the pixels in this pixmap into dst, applying the orientation transformations specified
+     *  by the flags. If the inputs are invalid, this returns false and no copy is made.
+     */
+    static bool Orient(const SkPixmap& dst, const SkPixmap& src, OrientFlags);
+};
+
+#endif
+