Add SkSpecialImage & SkSpecialSurface classes

tests/SpecialImageTest.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 "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkImage.h"
+#include "SkSpecialImage.h"
+#include "SkSpecialSurface.h"
+#include "Test.h"
+
+#if SK_SUPPORT_GPU
+#include "GrContext.h"
+#endif
+
+class TestingSpecialImageAccess {
+public:
+    static const SkIRect& Subset(const SkSpecialImage* img) {
+        return img->subset();
+    }
+
+    static bool PeekPixels(const SkSpecialImage* img, SkPixmap* pixmap) {
+        return img->peekPixels(pixmap);
+    }
+
+    static GrTexture* PeekTexture(const SkSpecialImage* img) {
+        return img->peekTexture();
+    }
+};
+
+// This test creates backing resources exactly sized to [kFullSize x kFullSize].
+// It then wraps them in an SkSpecialImage with only the center (red) region being active.
+// It then draws the SkSpecialImage to a full sized (all blue) canvas and checks that none
+// of the inactive (green) region leaked out.
+
+static const int kSmallerSize = 10;
+static const int kPad = 3;
+static const int kFullSize = kSmallerSize + 2 * kPad;
+
+// Create a bitmap with red in the center and green around it
+static SkBitmap create_bm() {
+    SkBitmap bm;
+    bm.allocN32Pixels(kFullSize, kFullSize, true);
+
+    SkCanvas temp(bm);
+
+    temp.clear(SK_ColorGREEN);
+    SkPaint p;
+    p.setColor(SK_ColorRED);
+    p.setAntiAlias(false);
+
+    temp.drawRect(SkRect::MakeXYWH(SkIntToScalar(kPad), SkIntToScalar(kPad),
+                                   SkIntToScalar(kSmallerSize), SkIntToScalar(kSmallerSize)), 
+                  p);
+
+    return bm;
+}
+
+// Basic test of the SkSpecialImage public API (e.g., peekTexture, peekPixels & draw)
+static void test_image(SkSpecialImage* img, skiatest::Reporter* reporter,
+                       bool peekPixelsSucceeds, bool peekTextureSucceeds) {
+    const SkIRect subset = TestingSpecialImageAccess::Subset(img);
+    REPORTER_ASSERT(reporter, kPad == subset.left());
+    REPORTER_ASSERT(reporter, kPad == subset.top());
+    REPORTER_ASSERT(reporter, kSmallerSize == subset.width());
+    REPORTER_ASSERT(reporter, kSmallerSize == subset.height());
+
+    //--------------
+    REPORTER_ASSERT(reporter, peekTextureSucceeds == !!TestingSpecialImageAccess::PeekTexture(img));
+
+    //--------------
+    SkPixmap pixmap;
+    REPORTER_ASSERT(reporter, peekPixelsSucceeds ==
+                              !!TestingSpecialImageAccess::PeekPixels(img, &pixmap));
+    if (peekPixelsSucceeds) {
+        REPORTER_ASSERT(reporter, kFullSize == pixmap.width());
+        REPORTER_ASSERT(reporter, kFullSize == pixmap.height());
+    }
+
+    //--------------
+    SkImageInfo info = SkImageInfo::MakeN32(kFullSize, kFullSize, kOpaque_SkAlphaType);
+
+    SkAutoTUnref<SkSpecialSurface> surf(img->newSurface(info));
+
+    SkCanvas* canvas = surf->getCanvas();
+
+    canvas->clear(SK_ColorBLUE);
+    img->draw(canvas, kPad, kPad, nullptr);
+
+    SkBitmap bm;
+    bm.allocN32Pixels(kFullSize, kFullSize, true);
+
+    bool result = canvas->readPixels(bm.info(), bm.getPixels(), bm.rowBytes(), 0, 0);
+    SkASSERT_RELEASE(result);
+
+    // Only the center (red) portion should've been drawn into the canvas
+    REPORTER_ASSERT(reporter, SK_ColorBLUE == bm.getColor(kPad-1, kPad-1));
+    REPORTER_ASSERT(reporter, SK_ColorRED  == bm.getColor(kPad, kPad));
+    REPORTER_ASSERT(reporter, SK_ColorRED  == bm.getColor(kSmallerSize+kPad-1,
+                                                          kSmallerSize+kPad-1));
+    REPORTER_ASSERT(reporter, SK_ColorBLUE == bm.getColor(kSmallerSize+kPad,
+                                                          kSmallerSize+kPad));
+}
+
+DEF_TEST(SpecialImage_Raster, reporter) {
+    SkBitmap bm = create_bm();
+
+    const SkIRect& subset = SkIRect::MakeXYWH(kPad, kPad, kSmallerSize, kSmallerSize);
+
+    SkAutoTUnref<SkSpecialImage> img(SkSpecialImage::NewFromRaster(subset, bm));
+    test_image(img, reporter, true, false);
+}
+
+DEF_TEST(SpecialImage_Image, reporter) {
+    SkBitmap bm = create_bm();
+
+    SkAutoTUnref<SkImage> fullImage(SkImage::NewFromBitmap(bm));
+
+    const SkIRect& subset = SkIRect::MakeXYWH(kPad, kPad, kSmallerSize, kSmallerSize);
+
+    SkAutoTUnref<SkSpecialImage> img(SkSpecialImage::NewFromImage(subset, fullImage));
+    test_image(img, reporter, true, false);
+}
+
+#if SK_SUPPORT_GPU
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SpecialImage_Gpu, reporter, context) {
+    SkBitmap bm = create_bm();
+
+    GrSurfaceDesc desc;
+    desc.fConfig = kSkia8888_GrPixelConfig;
+    desc.fFlags  = kNone_GrSurfaceFlags;
+    desc.fWidth  = kFullSize;
+    desc.fHeight = kFullSize;
+
+    SkAutoTUnref<GrTexture> texture(context->textureProvider()->createTexture(desc, false,
+                                                                              bm.getPixels(), 0));
+    if (!texture) {
+        return;
+    }
+
+    const SkIRect& subset = SkIRect::MakeXYWH(kPad, kPad, kSmallerSize, kSmallerSize);
+
+    SkAutoTUnref<SkSpecialImage> img(SkSpecialImage::NewFromGpu(subset, texture));
+    test_image(img, reporter, false, true);
+}
+
+#endif