src/third_party/skia/tests/MipMapTest.cpp

   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 "SkBitmap.h"
   9 #include "SkMipMap.h"
  10 #include "SkRandom.h"
  11 #include "Test.h"
  12
  13 static void make_bitmap(SkBitmap* bm, SkRandom& rand) {
  14     // for now, Build needs a min size of 2, otherwise it will return NULL.
  15     // should fix that to support 1 X N, where N > 1 to return non-null.
  16     int w = 2 + rand.nextU() % 1000;
  17     int h = 2 + rand.nextU() % 1000;
  18     bm->allocN32Pixels(w, h);
  19     bm->eraseColor(SK_ColorWHITE);
  20 }
  21
  22 DEF_TEST(MipMap, reporter) {
  23     SkBitmap bm;
  24     SkRandom rand;
  25
  26     for (int i = 0; i < 500; ++i) {
  27         make_bitmap(&bm, rand);
  28         SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, NULL));
  29
  30         REPORTER_ASSERT(reporter, !mm->extractLevel(SK_Scalar1, NULL));
  31         REPORTER_ASSERT(reporter, !mm->extractLevel(SK_Scalar1 * 2, NULL));
  32
  33         SkMipMap::Level prevLevel;
  34         sk_bzero(&prevLevel, sizeof(prevLevel));
  35
  36         SkScalar scale = SK_Scalar1;
  37         for (int j = 0; j < 30; ++j) {
  38             scale = scale * 2 / 3;
  39
  40             SkMipMap::Level level;
  41             if (mm->extractLevel(scale, &level)) {
  42                 REPORTER_ASSERT(reporter, level.fPixels);
  43                 REPORTER_ASSERT(reporter, level.fWidth > 0);
  44                 REPORTER_ASSERT(reporter, level.fHeight > 0);
  45                 REPORTER_ASSERT(reporter, level.fRowBytes >= level.fWidth * 4);
  46
  47                 if (prevLevel.fPixels) {
  48                     REPORTER_ASSERT(reporter, level.fWidth <= prevLevel.fWidth);
  49                     REPORTER_ASSERT(reporter, level.fHeight <= prevLevel.fHeight);
  50                 }
  51                 prevLevel = level;
  52             }
  53         }
  54     }
  55 }