implement isABitmap for imageshader, return localmatrix for bitmap's impl

tests/ShaderTest.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 "Test.h"
+#include "SkBitmap.h"
+#include "SkImage.h"
+#include "SkShader.h"
+#include "SkSurface.h"
+#include "SkData.h"
+
+static void check_isabitmap(skiatest::Reporter* reporter, SkShader* shader,
+                            int expectedW, int expectedH,
+                            SkShader::TileMode expectedX, SkShader::TileMode expectedY,
+                            const SkMatrix& expectedM,
+                            bool expectedImage) {
+    SkBitmap bm;
+    SkShader::TileMode tileModes[2];
+    SkMatrix localM;
+    REPORTER_ASSERT(reporter, shader->isABitmap(&bm, &localM, tileModes));
+    REPORTER_ASSERT(reporter, bm.width() == expectedW);
+    REPORTER_ASSERT(reporter, bm.height() == expectedH);
+    REPORTER_ASSERT(reporter, localM == expectedM);
+    REPORTER_ASSERT(reporter, tileModes[0] == expectedX);
+    REPORTER_ASSERT(reporter, tileModes[1] == expectedY);
+
+    // wack these so we don't get a false positive
+    localM.setScale(9999, -9999);
+    tileModes[0] = tileModes[1] = (SkShader::TileMode)99;
+
+    SkImage* image = shader->isAImage(&localM, tileModes);
+    REPORTER_ASSERT(reporter, (image != nullptr) == expectedImage);
+    if (image) {
+        REPORTER_ASSERT(reporter, image->width() == expectedW);
+        REPORTER_ASSERT(reporter, image->height() == expectedH);
+        REPORTER_ASSERT(reporter, localM == expectedM);
+        REPORTER_ASSERT(reporter, tileModes[0] == expectedX);
+        REPORTER_ASSERT(reporter, tileModes[1] == expectedY);
+    }
+}
+
+DEF_TEST(Shader_isABitmap, reporter) {
+    const int W = 100;
+    const int H = 100;
+    SkBitmap bm;
+    bm.allocN32Pixels(W, H);
+    auto img = SkImage::MakeFromBitmap(bm);
+    const SkMatrix localM = SkMatrix::MakeScale(2, 3);
+    const SkShader::TileMode tmx = SkShader::kRepeat_TileMode;
+    const SkShader::TileMode tmy = SkShader::kMirror_TileMode;
+
+    auto shader0 = SkShader::MakeBitmapShader(bm, tmx, tmy, &localM);
+    auto shader1 = SkImage::MakeFromBitmap(bm)->makeShader(tmx, tmy, &localM);
+
+    check_isabitmap(reporter, shader0.get(), W, H, tmx, tmy, localM, false);
+    check_isabitmap(reporter, shader1.get(), W, H, tmx, tmy, localM, true);
+}