Improve naive SkColorXform to half floats

bench/ColorCodecBench.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "ColorCodecBench.h"
 #include "Resources.h"
 #include "SkCodec.h"
 #include "SkColorSpaceXform.h"
 #include "SkCommandLineFlags.h"
 
 #if defined(SK_TEST_QCMS)
 DEFINE_bool(qcms,       false, "Bench qcms color conversion");
 #endif
 DEFINE_bool(xform_only, false, "Only time the color xform, do not include the decode time");
 DEFINE_bool(srgb,       false, "Convert to srgb dst space");
+DEFINE_bool(half,       false, "Convert to half floats");
 
 ColorCodecBench::ColorCodecBench(const char* name, sk_sp<SkData> encoded)
     : fEncoded(std::move(encoded))
 #if defined(SK_TEST_QCMS)
     , fDstSpaceQCMS(nullptr)
 #endif
 {
     fName.appendf("Color%s", FLAGS_xform_only ? "Xform" : "Codec");
 #if defined(SK_TEST_QCMS)
     fName.appendf("%s", FLAGS_qcms ? "QCMS" : "");
 #endif
     fName.appendf("_%s", name);
 }
 
 const char* ColorCodecBench::onGetName() {
     return fName.c_str();
 }
 
 bool ColorCodecBench::isSuitableFor(Backend backend) {
     return kNonRendering_Backend == backend;
 }
 
 void ColorCodecBench::decodeAndXform() {
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(fEncoded.get()));
 #ifdef SK_DEBUG
     const SkCodec::Result result =
 #endif
-    codec->startScanlineDecode(fInfo);
+    codec->startScanlineDecode(fSrcInfo);
     SkASSERT(SkCodec::kSuccess == result);
 
     sk_sp<SkColorSpace> srcSpace = sk_ref_sp(codec->getColorSpace());
     if (!srcSpace) {
         srcSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
     }
     std::unique_ptr<SkColorSpaceXform> xform = SkColorSpaceXform::New(srcSpace, fDstSpace);
     SkASSERT(xform);
 
     void* dst = fDst.get();
-    for (int y = 0; y < fInfo.height(); y++) {
+    for (int y = 0; y < fSrcInfo.height(); y++) {
 #ifdef SK_DEBUG
         const int rows =
 #endif
         codec->getScanlines(fSrc.get(), 1, 0);
         SkASSERT(1 == rows);
 
-        xform->applyTo8888((SkPMColor*) dst, (uint32_t*) fSrc.get(), fInfo.width());
-        dst = SkTAddOffset<void>(dst, fInfo.minRowBytes());
+        FLAGS_half ?
+                xform->applyToF16((uint64_t*) dst, (uint32_t*) fSrc.get(), fSrcInfo.width()) :
+                xform->applyTo8888((SkPMColor*) dst, (uint32_t*) fSrc.get(), fSrcInfo.width());
+        dst = SkTAddOffset<void>(dst, fDstInfo.minRowBytes());
     }
 }
 
 #if defined(SK_TEST_QCMS)
 void ColorCodecBench::decodeAndXformQCMS() {
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(fEncoded.get()));
 #ifdef SK_DEBUG
     const SkCodec::Result result =
 #endif
-    codec->startScanlineDecode(fInfo);
+    codec->startScanlineDecode(fSrcInfo);
     SkASSERT(SkCodec::kSuccess == result);
 
     SkAutoTCallVProc<qcms_profile, qcms_profile_release>
             srcSpace(qcms_profile_from_memory(fSrcData->data(), fSrcData->size()));
     SkASSERT(srcSpace);
 
     SkAutoTCallVProc<qcms_transform, qcms_transform_release>
             transform (qcms_transform_create(srcSpace, QCMS_DATA_RGBA_8, fDstSpaceQCMS.get(),
                                              QCMS_DATA_RGBA_8, QCMS_INTENT_PERCEPTUAL));
     SkASSERT(transform);
 
 #ifdef SK_PMCOLOR_IS_RGBA
     qcms_output_type outType = QCMS_OUTPUT_RGBX;
 #else
     qcms_output_type outType = QCMS_OUTPUT_BGRX;
 #endif
 
     void* dst = fDst.get();
-    for (int y = 0; y < fInfo.height(); y++) {
+    for (int y = 0; y < fSrcInfo.height(); y++) {
 #ifdef SK_DEBUG
         const int rows =
 #endif
         codec->getScanlines(fSrc.get(), 1, 0);
         SkASSERT(1 == rows);
 
-        qcms_transform_data_type(transform, fSrc.get(), dst, fInfo.width(), outType);
-        dst = SkTAddOffset<void>(dst, fInfo.minRowBytes());
+        qcms_transform_data_type(transform, fSrc.get(), dst, fSrcInfo.width(), outType);
+        dst = SkTAddOffset<void>(dst, fDstInfo.minRowBytes());
     }
 }
 #endif
 
 void ColorCodecBench::xformOnly() {
     sk_sp<SkColorSpace> srcSpace = SkColorSpace::NewICC(fSrcData->data(), fSrcData->size());
     if (!srcSpace) {
         srcSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
     }
     std::unique_ptr<SkColorSpaceXform> xform = SkColorSpaceXform::New(srcSpace, fDstSpace);
     SkASSERT(xform);
 
     void* dst = fDst.get();
     void* src = fSrc.get();
-    for (int y = 0; y < fInfo.height(); y++) {
+    for (int y = 0; y < fSrcInfo.height(); y++) {
         // Transform in place
-        xform->applyTo8888((SkPMColor*) dst, (uint32_t*) src, fInfo.width());
-        dst = SkTAddOffset<void>(dst, fInfo.minRowBytes());
-        src = SkTAddOffset<void>(src, fInfo.minRowBytes());
+        FLAGS_half ?
+                xform->applyToF16((uint64_t*) dst, (uint32_t*) src, fSrcInfo.width()) :
+                xform->applyTo8888((SkPMColor*) dst, (uint32_t*) src, fSrcInfo.width());
+        dst = SkTAddOffset<void>(dst, fDstInfo.minRowBytes());
+        src = SkTAddOffset<void>(src, fSrcInfo.minRowBytes());
     }
 }
 
 #if defined(SK_TEST_QCMS)
 void ColorCodecBench::xformOnlyQCMS() {
     SkAutoTCallVProc<qcms_profile, qcms_profile_release>
             srcSpace(qcms_profile_from_memory(fSrcData->data(), fSrcData->size()));
     SkASSERT(srcSpace);
 
     SkAutoTCallVProc<qcms_transform, qcms_transform_release>
             transform (qcms_transform_create(srcSpace, QCMS_DATA_RGBA_8, fDstSpaceQCMS.get(),
                                              QCMS_DATA_RGBA_8, QCMS_INTENT_PERCEPTUAL));
     SkASSERT(transform);
 
 #ifdef SK_PMCOLOR_IS_RGBA
     qcms_output_type outType = QCMS_OUTPUT_RGBX;
 #else
     qcms_output_type outType = QCMS_OUTPUT_BGRX;
 #endif
 
     void* dst = fDst.get();
     void* src = fSrc.get();
-    for (int y = 0; y < fInfo.height(); y++) {
+    for (int y = 0; y < fSrcInfo.height(); y++) {
         // Transform in place
-        qcms_transform_data_type(transform, src, dst, fInfo.width(), outType);
-        dst = SkTAddOffset<void>(dst, fInfo.minRowBytes());
-        src = SkTAddOffset<void>(src, fInfo.minRowBytes());
+        qcms_transform_data_type(transform, src, dst, fSrcInfo.width(), outType);
+        dst = SkTAddOffset<void>(dst, fDstInfo.minRowBytes());
+        src = SkTAddOffset<void>(src, fSrcInfo.minRowBytes());
     }
 }
 #endif
 
 void ColorCodecBench::onDelayedSetup() {
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(fEncoded.get()));
-    fInfo = codec->getInfo().makeColorType(kRGBA_8888_SkColorType);
+    fSrcInfo = codec->getInfo().makeColorType(kRGBA_8888_SkColorType);
 
-    fDst.reset(fInfo.getSafeSize(fInfo.minRowBytes()));
+    fDstInfo = fSrcInfo;
+    if (FLAGS_half) {
+        fDstInfo = fDstInfo.makeColorType(kRGBA_F16_SkColorType);
+    }
+    fDst.reset(fDstInfo.getSafeSize(fDstInfo.minRowBytes()));
+
     if (FLAGS_xform_only) {
-        fSrc.reset(fInfo.getSafeSize(fInfo.minRowBytes()));
-        codec->getPixels(fInfo, fSrc.get(), fInfo.minRowBytes());
+        fSrc.reset(fSrcInfo.getSafeSize(fSrcInfo.minRowBytes()));
+        codec->getPixels(fSrcInfo, fSrc.get(), fSrcInfo.minRowBytes());
     } else {
         // Set-up a row buffer to decode into before transforming to dst.
-        fSrc.reset(fInfo.minRowBytes());
+        fSrc.reset(fSrcInfo.minRowBytes());
     }
 
     fSrcData = codec->getICCData();
     sk_sp<SkData> dstData = SkData::MakeFromFileName(
             GetResourcePath("monitor_profiles/HP_ZR30w.icc").c_str());
     SkASSERT(dstData);
 
 
 #if defined(SK_TEST_QCMS)
     if (FLAGS_qcms) {
         fDstSpaceQCMS.reset(FLAGS_srgb ?
                 qcms_profile_sRGB() :
                 qcms_profile_from_memory(dstData->data(), dstData->size()));
         SkASSERT(fDstSpaceQCMS);
 
         // This call takes a non-trivial amount of time, but I think it's the most fair to
         // treat it as overhead.  It only needs to happen once.
         qcms_profile_precache_output_transform(fDstSpaceQCMS);
     } else
 #endif
     {
         fDstSpace = FLAGS_srgb ? SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named) :
                                  SkColorSpace::NewICC(dstData->data(), dstData->size());
         SkASSERT(fDstSpace);
     }
 }
 
 void ColorCodecBench::onDraw(int n, SkCanvas*) {
+    if ((FLAGS_srgb || FLAGS_qcms) && FLAGS_half) {
+        SkDebugf("Error: Contradicting flags.\n");
+        return;
+    }
+
     for (int i = 0; i < n; i++) {
 #if defined(SK_TEST_QCMS)
         if (FLAGS_qcms) {
             if (FLAGS_xform_only) {
                 this->xformOnlyQCMS();
             } else {
                 this->decodeAndXformQCMS();
             }
         } else
 #endif
         {
             if (FLAGS_xform_only) {
                 this->xformOnly();
             } else {
                 this->decodeAndXform();
             }
         }
     }
 }