SkCanvas interface for drawing a patch.

Added function SkCanvas::drawPatch to the API. This function
receives the patch to draw and the paint.

Added function SkBaseDevice::drawPatch to the API. This function also receives the patch to draw and the paint.

Currently SkGpuDevice and SkBitmapDevice generate the mesh taking into
account the scale factor and call the corresponding device's drawVertices.

BUG=skia:
R=jvanverth@google.com, egdaniel@google.com, bsalomon@google.com

Author: dandov@google.com

Review URL: https://codereview.chromium.org/424663006

1 files changed, 88 insertions, 58 deletions

diff --git a/gm/patch.cpp b/gm/patch.cpp
index eb99944c0b..5658ef6a88 100644
--- a/gm/patch.cpp
+++ b/gm/patch.cpp
@@ -14,14 +14,71 @@
 
 #include "GrContext.h"
 #include "GrTest.h"
-
 #include "SkPatch.h"
 
+static void draw_control_points(SkCanvas* canvas, SkPatch& patch, SkPaint& paint) {
+    //draw control points
+    SkPaint copy(paint);
+    SkPoint bottom[4];
+    patch.getBottomPoints(bottom);
+    SkPoint top[4];
+    patch.getTopPoints(top);
+    SkPoint left[4];
+    patch.getLeftPoints(left);
+    SkPoint right[4];
+    patch.getRightPoints(right);
+
+    copy.setColor(SK_ColorBLACK);
+    copy.setStrokeWidth(0.5);
+    SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom+1, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, copy);
+
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top+1, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left+1, copy);
+    canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right+1, copy);
+
+    copy.setStrokeWidth(2);
+
+    copy.setColor(SK_ColorRED);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, copy);
+
+    copy.setColor(SK_ColorBLUE);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom+1, copy);
+
+    copy.setColor(SK_ColorCYAN);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top+1, copy);
+
+    copy.setColor(SK_ColorYELLOW);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left+1, copy);
+
+    copy.setColor(SK_ColorGREEN);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right+1, copy);
+}
+
+static void draw_random_patch(SkPoint points[12], SkColor colors[4], SkCanvas* canvas,
+                              SkPaint& paint, SkRandom* rnd) {
+    SkPoint ptsCpy[12];
+    memcpy(ptsCpy, points, 12 * sizeof(SkPoint));
+    for (int i = 0; i < 5; i++) {
+        int index = rnd->nextRangeU(0, 11);
+        SkScalar dx = rnd->nextRangeScalar(-50, 50), dy = rnd->nextRangeScalar(-50, 50);
+        ptsCpy[index].offset(dx, dy);
+    }
+    SkPatch patch(ptsCpy, colors);
+    canvas->drawPatch(patch, paint);
+    draw_control_points(canvas, patch, paint);
+}
+
 namespace skiagm {
 /**
  * This GM draws a SkPatch.
  */
 class SkPatchGM : public GM {
+    
 public:
     SkPatchGM() {
         this->setBGColor(0xFFFFFFFF);
@@ -37,77 +94,50 @@ protected:
     }
 
     virtual uint32_t onGetFlags() const SK_OVERRIDE {
-        return kGPUOnly_Flag;
+        return kSkipTiled_Flag | kSkipPipe_Flag | kSkipPicture_Flag;
     }
-
-
+    
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
-
+        
         SkPaint paint;
         SkColor colors[4] = {
             SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
         };
-        SkPoint points[] = {
-            {100,100},{130,50},{500,70}, {650,60},
-            {350,125},{490,555},{600,700},
-            {515,595},{140,550},{110,590},
-            {125,400},{70,150}
-            
+        SkPoint points[12] = {
+            {50,50},{75,20},{125,80}, {150,50},
+            {120,75},{180,125},{150,150},
+            {125,120},{75,180},{50,150},
+            {20,125},{80,75}
         };
-
-        SkPatch coons(points, colors);
         
-        SkPatch::VertexData data;
-        coons.getVertexData(&data, 10);
-
-        canvas->drawVertices(SkCanvas::kTriangles_VertexMode,data.fVertexCount,
-            data.fPoints, data.fTexCoords, data.fColors, NULL, data.fIndices,
-            data.fIndexCount, paint);
-
-        //draw control points
-        SkPoint bottom[4];
-        coons.getBottomPoints(bottom);
-        SkPoint top[4];
-        coons.getTopPoints(top);
-        SkPoint left[4];
-        coons.getLeftPoints(left);
-        SkPoint right[4];
-        coons.getRightPoints(right);
-
-        SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom+1, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
-
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top+1, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left+1, paint);
-        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right+1, paint);
-
-        paint.setStrokeWidth(10);
-
-        paint.setColor(SK_ColorRED);
-        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
-
-        paint.setColor(SK_ColorBLUE);
-        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom+1, paint);
-
-        paint.setColor(SK_ColorCYAN);
-        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top+1, paint);
-
-        paint.setColor(SK_ColorYELLOW);
-        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left+1, paint);
-
-        paint.setColor(SK_ColorGREEN);
-        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right+1, paint);
+        SkRandom rnd;
+        SkScalar scale = 0.5f;
+        canvas->save();
+        for (SkScalar x = 0; x < 4; x++) {
+            canvas->save();
+            canvas->scale(scale * (x + 1), scale * (x + 1));
+            canvas->translate(x * 100, 0);
+            draw_random_patch(points, colors, canvas, paint, &rnd);
+            canvas->restore();
+        }
+        canvas->translate(0, 270);
+        SkScalar skew = 0.1f;
+        for (SkScalar x = 0; x < 4; x++) {
+            canvas->save();
+            canvas->scale(scale * (x + 1), scale * (x + 1));
+            canvas->skew(skew * (x + 1), skew * (x + 1));
+            canvas->translate(x * 100, 0);
+            draw_random_patch(points, colors, canvas, paint, &rnd);
+            canvas->restore();
+        }
+        canvas->restore();
     }
 
 private:
     typedef GM INHERITED;
 };
 
-DEF_GM( return SkNEW(SkPatchGM); )
+DEF_GM(return SkNEW(SkPatchGM); )
 
 }