Fixed a bug with linear gradient PDF matrices and added test cases
R=vandebo@chromium.org, reed@google.com
Author: richardlin@chromium.org
Review URL: https://chromiumcodereview.appspot.com/16094020
git-svn-id: http://skia.googlecode.com/svn/trunk@9553 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gradient_matrix.cpp b/gm/gradient_matrix.cpp
new file mode 100644
index 0000000..cc1683e
--- /dev/null
+++ b/gm/gradient_matrix.cpp
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCanvas.h"
+#include "SkColor.h"
+#include "SkGradientShader.h"
+#include "SkMatrix.h"
+#include "SkPaint.h"
+#include "SkPoint.h"
+#include "SkRect.h"
+#include "SkRefCnt.h"
+#include "SkScalar.h"
+#include "SkSize.h"
+#include "SkString.h"
+
+#include "gm.h"
+
+static const SkColor gColors[] = {
+ SK_ColorRED, SK_ColorYELLOW
+};
+
+// these arrays define the gradient stop points
+// as x1, y1, x2, y2 per gradient to draw
+static const SkPoint linearPts[][2] = {
+ {{0, 0}, {1, 0}},
+ {{0, 0}, {0, 1}},
+ {{1, 0}, {0, 0}},
+ {{0, 1}, {0, 0}},
+
+ {{0, 0}, {1, 1}},
+ {{1, 1}, {0, 0}},
+ {{1, 0}, {0, 1}},
+ {{0, 1}, {1, 0}}
+};
+
+static const SkScalar TESTGRID_X = 200; // pixels allocated to each image in x dimension
+static const SkScalar TESTGRID_Y = 200; // pixels allocated to each image in y dimension
+
+static const int IMAGES_X = 4; // number of images per row
+
+static SkShader* make_linear_gradient(const SkPoint pts[2]) {
+ return SkGradientShader::CreateLinear(pts, gColors, NULL, SK_ARRAY_COUNT(gColors),
+ SkShader::kClamp_TileMode, NULL);
+}
+
+static void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(const SkPoint[2]),
+ const SkPoint ptsArray[][2], int numImages) {
+ // Use some nice prime numbers for the rectangle and matrix with
+ // different scaling along the x and y axes (which is the bug this
+ // test addresses, where incorrect order of operations mixed up the axes)
+ SkRect rectGrad = { 43, 61, 181, 167 };
+ SkMatrix shaderMat;
+ shaderMat.setScale(rectGrad.width(), rectGrad.height());
+ shaderMat.postTranslate(rectGrad.left(), rectGrad.top());
+
+ canvas->save();
+ for (int i = 0; i < numImages; i++) {
+ // Advance line downwards if necessary.
+ if (i % IMAGES_X == 0 && i != 0) {
+ canvas->restore();
+ canvas->translate(0, TESTGRID_Y);
+ canvas->save();
+ }
+
+ // Setup shader and draw.
+ SkAutoTUnref<SkShader> shader(makeShader(*ptsArray));
+ shader->setLocalMatrix(shaderMat);
+
+ SkPaint paint;
+ paint.setShader(shader);
+ canvas->drawRect(rectGrad, paint);
+
+ // Advance to next position.
+ canvas->translate(TESTGRID_X, 0);
+ ptsArray++;
+ }
+ canvas->restore();
+}
+
+namespace skiagm {
+
+class GradientMatrixGM : public GM {
+public:
+ GradientMatrixGM() {
+ this->setBGColor(0xFFDDDDDD);
+ }
+
+protected:
+ SkString onShortName() SK_OVERRIDE {
+ return SkString("gradient_matrix");
+ }
+
+ virtual SkISize onISize() SK_OVERRIDE {
+ return SkISize::Make(800, 800);
+ }
+
+ virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+ draw_gradients(canvas, &make_linear_gradient,
+ linearPts, SK_ARRAY_COUNT(linearPts));
+ }
+
+private:
+ typedef GM INHERITED;
+};
+
+DEF_GM( return new GradientMatrixGM; )
+}