[SkSVGDevice] Add support for image shaders.

Below is an example of the generated svg for an image shader
that repeats in the x direction only:

<svg stroke="none" x="9" y="153" width="50" height="30">
  <defs>
    <pattern id="pattern_1_19" patternUnits="userSpaceOnUse" patternContentUnits="userSpaceOnUse" width="31" height="100%" x="0" y="0">
      <image id="img_2_19" x="0" y="0" width="31" height="30" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="data:image/png;base64,LONG_B64_STRING_HERE"></image>
    </pattern>
  </defs>
  <rect fill="url(#pattern_1_19)" stroke="none" x="0" y="0" width="100%" height="100%"></rect>
</svg>

Matching the height of the pattern with the height of the container prevents it from repeating in the y direction.

R=fmalita@chromium.org

Bug: skia::7681
Change-Id: I43e4f19acda4bd40c7a8b5259d67c26a108d6f67
Reviewed-on: https://skia-review.googlesource.com/111420
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Florin Malita <fmalita@chromium.org>

1 files changed, 184 insertions, 5 deletions

diff --git a/tests/SVGDeviceTest.cpp b/tests/SVGDeviceTest.cpp
index 7044559d83..bdd832c43b 100644
--- a/tests/SVGDeviceTest.cpp
+++ b/tests/SVGDeviceTest.cpp
@@ -5,23 +5,27 @@
  * found in the LICENSE file.
  */
 
-#include "SkTypes.h"
-
-#ifdef SK_XML
 
+#include "SkBitmap.h"
 #include "SkCanvas.h"
-#include "SkData.h"
 #include "SkDOM.h"
+#include "SkData.h"
+#include "SkImage.h"
+#include "SkImageShader.h"
 #include "SkParse.h"
-#include "SkStream.h"
 #include "SkSVGCanvas.h"
+#include "SkShader.h"
+#include "SkStream.h"
 #include "SkXMLWriter.h"
 #include "Test.h"
 
 #include <string.h>
 
+#ifdef SK_XML
+
 namespace {
 
+
 void check_text_node(skiatest::Reporter* reporter,
                      const SkDOM& dom,
                      const SkDOM::Node* root,
@@ -149,4 +153,179 @@ DEF_TEST(SVGDevice_whitespace_pos, reporter) {
     }
 }
 
+
+void SetImageShader(SkPaint* paint, int imageWidth, int imageHeight, SkShader::TileMode xTile,
+                    SkShader::TileMode yTile) {
+    auto surface = SkSurface::MakeRasterN32Premul(imageWidth, imageHeight);
+    paint->setShader(SkImageShader::Make(surface->makeImageSnapshot(), xTile, yTile, nullptr));
+}
+
+// Attempt to find the three nodes on which we have expectations:
+// the pattern node, the image within that pattern, and the rect which
+// uses the pattern as a fill.
+// returns false if not all nodes are found.
+bool FindImageShaderNodes(skiatest::Reporter* reporter, const SkDOM* dom, const SkDOM::Node* root,
+                          const SkDOM::Node** patternOut, const SkDOM::Node** imageOut,
+                          const SkDOM::Node** rectOut) {
+    if (root == nullptr || dom == nullptr) {
+        ERRORF(reporter, "root element not found");
+        return false;
+    }
+
+
+    const SkDOM::Node* rect = dom->getFirstChild(root, "rect");
+    if (rect == nullptr) {
+        ERRORF(reporter, "rect not found");
+        return false;
+    }
+    *rectOut = rect;
+
+    const SkDOM::Node* defs = dom->getFirstChild(root, "defs");
+    if (defs == nullptr) {
+        ERRORF(reporter, "defs not found");
+        return false;
+    }
+
+    const SkDOM::Node* pattern = dom->getFirstChild(defs, "pattern");
+    if (pattern == nullptr) {
+        ERRORF(reporter, "pattern not found");
+        return false;
+    }
+    *patternOut = pattern;
+
+    const SkDOM::Node* image = dom->getFirstChild(pattern, "image");
+    if (image == nullptr) {
+        ERRORF(reporter, "image not found");
+        return false;
+    }
+    *imageOut = image;
+
+    return true;
+}
+
+void ImageShaderTestSetup(SkDOM* dom, SkPaint* paint, int imageWidth, int imageHeight,
+                          int rectWidth, int rectHeight, SkShader::TileMode xTile,
+                          SkShader::TileMode yTile) {
+    SetImageShader(paint, imageWidth, imageHeight, xTile, yTile);
+    SkXMLParserWriter writer(dom->beginParsing());
+    std::unique_ptr<SkCanvas> svgCanvas = SkSVGCanvas::Make(SkRect::MakeWH(100, 100), &writer);
+
+    SkRect bounds{0, 0, SkIntToScalar(rectWidth), SkIntToScalar(rectHeight)};
+    svgCanvas->drawRect(bounds, *paint);
+}
+
+
+DEF_TEST(SVGDevice_image_shader_norepeat, reporter) {
+    SkDOM dom;
+    SkPaint paint;
+    int imageWidth = 3, imageHeight = 3;
+    int rectWidth = 10, rectHeight = 10;
+    ImageShaderTestSetup(&dom, &paint, imageWidth, imageHeight, rectWidth, rectHeight,
+                         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
+
+    const SkDOM::Node* root = dom.finishParsing();
+
+    const SkDOM::Node *patternNode, *imageNode, *rectNode;
+    bool structureAppropriate =
+            FindImageShaderNodes(reporter, &dom, root, &patternNode, &imageNode, &rectNode);
+    REPORTER_ASSERT(reporter, structureAppropriate);
+
+    // the image should always maintain its size.
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "width")) == imageWidth);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "height")) == imageHeight);
+
+    // making the pattern as large as the container prevents
+    // it from repeating.
+    REPORTER_ASSERT(reporter, strcmp(dom.findAttr(patternNode, "width"), "100%") == 0);
+    REPORTER_ASSERT(reporter, strcmp(dom.findAttr(patternNode, "height"), "100%") == 0);
+}
+
+DEF_TEST(SVGDevice_image_shader_tilex, reporter) {
+    SkDOM dom;
+    SkPaint paint;
+    int imageWidth = 3, imageHeight = 3;
+    int rectWidth = 10, rectHeight = 10;
+    ImageShaderTestSetup(&dom, &paint, imageWidth, imageHeight, rectWidth, rectHeight,
+                         SkShader::kRepeat_TileMode, SkShader::kClamp_TileMode);
+
+    const SkDOM::Node* root = dom.finishParsing();
+    const SkDOM::Node* innerSvg = dom.getFirstChild(root, "svg");
+    if (innerSvg == nullptr) {
+        ERRORF(reporter, "inner svg element not found");
+        return;
+    }
+
+    const SkDOM::Node *patternNode, *imageNode, *rectNode;
+    bool structureAppropriate =
+            FindImageShaderNodes(reporter, &dom, innerSvg, &patternNode, &imageNode, &rectNode);
+    REPORTER_ASSERT(reporter, structureAppropriate);
+
+    // the imageNode should always maintain its size.
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "width")) == imageWidth);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "height")) == imageHeight);
+
+    // if the patternNode width matches the imageNode width,
+    // it will repeat in along the x axis.
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(patternNode, "width")) == imageWidth);
+    REPORTER_ASSERT(reporter, strcmp(dom.findAttr(patternNode, "height"), "100%") == 0);
+}
+
+DEF_TEST(SVGDevice_image_shader_tiley, reporter) {
+    SkDOM dom;
+    SkPaint paint;
+    int imageNodeWidth = 3, imageNodeHeight = 3;
+    int rectNodeWidth = 10, rectNodeHeight = 10;
+    ImageShaderTestSetup(&dom, &paint, imageNodeWidth, imageNodeHeight, rectNodeWidth,
+                         rectNodeHeight, SkShader::kClamp_TileMode, SkShader::kRepeat_TileMode);
+
+    const SkDOM::Node* root = dom.finishParsing();
+    const SkDOM::Node* innerSvg = dom.getFirstChild(root, "svg");
+    if (innerSvg == nullptr) {
+        ERRORF(reporter, "inner svg element not found");
+        return;
+    }
+
+    const SkDOM::Node *patternNode, *imageNode, *rectNode;
+    bool structureAppropriate =
+            FindImageShaderNodes(reporter, &dom, innerSvg, &patternNode, &imageNode, &rectNode);
+    REPORTER_ASSERT(reporter, structureAppropriate);
+
+    // the imageNode should always maintain its size.
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "width")) == imageNodeWidth);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "height")) == imageNodeHeight);
+
+    // making the patternNode as large as the container prevents
+    // it from repeating.
+    REPORTER_ASSERT(reporter, strcmp(dom.findAttr(patternNode, "width"), "100%") == 0);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(patternNode, "height")) == imageNodeHeight);
+}
+
+DEF_TEST(SVGDevice_image_shader_tileboth, reporter) {
+    SkDOM dom;
+    SkPaint paint;
+    int imageWidth = 3, imageHeight = 3;
+    int rectWidth = 10, rectHeight = 10;
+    ImageShaderTestSetup(&dom, &paint, imageWidth, imageHeight, rectWidth, rectHeight,
+                         SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
+
+    const SkDOM::Node* root = dom.finishParsing();
+
+    const SkDOM::Node *patternNode, *imageNode, *rectNode;
+    const SkDOM::Node* innerSvg = dom.getFirstChild(root, "svg");
+    if (innerSvg == nullptr) {
+        ERRORF(reporter, "inner svg element not found");
+        return;
+    }
+    bool structureAppropriate =
+            FindImageShaderNodes(reporter, &dom, innerSvg, &patternNode, &imageNode, &rectNode);
+    REPORTER_ASSERT(reporter, structureAppropriate);
+
+    // the imageNode should always maintain its size.
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "width")) == imageWidth);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(imageNode, "height")) == imageHeight);
+
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(patternNode, "width")) == imageWidth);
+    REPORTER_ASSERT(reporter, atoi(dom.findAttr(patternNode, "height")) == imageHeight);
+}
+
 #endif