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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "gm.h"
      9 #include "SkBitmap.h"
     10 #include "SkCanvas.h"
     11 #include "SkColorPriv.h"
     12 
     13 /**
     14  * This GM checks that bitmap pixels are unpremultiplied before being exported
     15  * to other formats. If unpremultiplication is implemented properly, this
     16  * GM should come out completely white. If not, this GM looks like a row of two
     17  * greyscale gradients above a row of grey lines.
     18  * This tests both the ARGB4444 and ARGB8888 bitmap configurations.
     19  */
     20 
     21 constexpr int SLIDE_SIZE = 256;
     22 constexpr int PIXEL_SIZE_8888 = SLIDE_SIZE / 256;
     23 constexpr int PIXEL_SIZE_4444 = SLIDE_SIZE / 16;
     24 
     25 static void init_bitmap(SkColorType ct, SkBitmap* bitmap) {
     26     bitmap->allocPixels(SkImageInfo::Make(SLIDE_SIZE, SLIDE_SIZE, ct,
     27                                           kPremul_SkAlphaType));
     28     bitmap->eraseColor(SK_ColorWHITE);
     29 }
     30 
     31 static SkBitmap make_argb8888_gradient() {
     32     SkBitmap bitmap;
     33     init_bitmap(kN32_SkColorType, &bitmap);
     34     uint8_t rowColor = 0;
     35     for (int y = 0; y < SLIDE_SIZE; y++) {
     36         uint32_t* dst = bitmap.getAddr32(0, y);
     37         for (int x = 0; x < SLIDE_SIZE; x++) {
     38             dst[x] = SkPackARGB32(rowColor, rowColor,
     39                                   rowColor, rowColor);
     40         }
     41         if (y % PIXEL_SIZE_8888 == PIXEL_SIZE_8888 - 1) {
     42             rowColor++;
     43         }
     44     }
     45     return bitmap;
     46 }
     47 
     48 static SkBitmap make_argb4444_gradient() {
     49     SkBitmap bitmap;
     50     init_bitmap(kARGB_4444_SkColorType, &bitmap);
     51     uint8_t rowColor = 0;
     52     for (int y = 0; y < SLIDE_SIZE; y++) {
     53         uint16_t* dst = bitmap.getAddr16(0, y);
     54         for (int x = 0; x < SLIDE_SIZE; x++) {
     55             dst[x] = SkPackARGB4444(rowColor, rowColor,
     56                                     rowColor, rowColor);
     57         }
     58         if (y % PIXEL_SIZE_4444 == PIXEL_SIZE_4444 - 1) {
     59             rowColor++;
     60         }
     61     }
     62     return bitmap;
     63 }
     64 
     65 static SkBitmap make_argb8888_stripes() {
     66     SkBitmap bitmap;
     67     init_bitmap(kN32_SkColorType, &bitmap);
     68     uint8_t rowColor = 0;
     69     for (int y = 0; y < SLIDE_SIZE; y++) {
     70         uint32_t* dst = bitmap.getAddr32(0, y);
     71         for (int x = 0; x < SLIDE_SIZE; x++) {
     72             dst[x] = SkPackARGB32(rowColor, rowColor,
     73                                   rowColor, rowColor);
     74         }
     75         if (rowColor == 0) {
     76             rowColor = 255;
     77         } else {
     78             rowColor = 0;
     79         }
     80     }
     81     return bitmap;
     82 }
     83 
     84 static SkBitmap make_argb4444_stripes() {
     85     SkBitmap bitmap;
     86     init_bitmap(kARGB_4444_SkColorType, &bitmap);
     87     uint8_t rowColor = 0;
     88     for (int y = 0; y < SLIDE_SIZE; y++) {
     89         uint16_t* dst = bitmap.getAddr16(0, y);
     90         for (int x = 0; x < SLIDE_SIZE; x++) {
     91             dst[x] = SkPackARGB4444(rowColor, rowColor,
     92                                     rowColor, rowColor);
     93         }
     94         if (rowColor == 0) {
     95             rowColor = 15;
     96         } else {
     97             rowColor = 0;
     98         }
     99     }
    100     return bitmap;
    101 }
    102 
    103 namespace skiagm {
    104 
    105 class BitmapPremulGM : public GM {
    106 public:
    107     BitmapPremulGM() {
    108         this->setBGColor(SK_ColorWHITE);
    109     }
    110 
    111 protected:
    112     SkString onShortName() override {
    113         return SkString("bitmap_premul");
    114     }
    115 
    116     SkISize onISize() override {
    117         return SkISize::Make(SLIDE_SIZE * 2, SLIDE_SIZE * 2);
    118     }
    119 
    120     void onDraw(SkCanvas* canvas) override {
    121         SkScalar slideSize = SkIntToScalar(SLIDE_SIZE);
    122         canvas->drawBitmap(make_argb8888_gradient(), 0, 0);
    123         canvas->drawBitmap(make_argb4444_gradient(), slideSize, 0);
    124         canvas->drawBitmap(make_argb8888_stripes(), 0, slideSize);
    125         canvas->drawBitmap(make_argb4444_stripes(), slideSize, slideSize);
    126     }
    127 
    128 private:
    129     typedef GM INHERITED;
    130 };
    131 
    132 DEF_GM( return new BitmapPremulGM; )
    133 }
    134