SkCanvas::drawPatch param SkPoint[12]

gm/patch.cpp

Index: gm/patch.cpp
diff --git a/gm/patch.cpp b/gm/patch.cpp
index 3f1e07910be6ea21407018c8a2bb5134ea03e77c..5873403dde10d012e1e0f81bb05998924a90c732 100644
--- a/gm/patch.cpp
+++ b/gm/patch.cpp
@@ -14,32 +14,45 @@
 
 #include "GrContext.h"
 #include "GrTest.h"
+#include "SkGradientShader.h"
 #include "SkPatch.h"
+#include "SkPatchUtils.h"
+
+static SkShader* make_shader() {
+    const SkColor colors[] = {
+        SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE, SK_ColorMAGENTA, SK_ColorBLUE,
+        SK_ColorYELLOW,
+    };
+    const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } };
+    
+    return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+                                          SkShader::kMirror_TileMode);
+}
 
-static void draw_control_points(SkCanvas* canvas, const SkPatch& patch) {
+static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) {
     //draw control points
     SkPaint paint;
     SkPoint bottom[SkPatch::kNumPtsCubic];
-    patch.getBottomPoints(bottom);
+    SkPatchUtils::getBottomCubic(cubics, bottom);
     SkPoint top[SkPatch::kNumPtsCubic];
-    patch.getTopPoints(top);
+    SkPatchUtils::getTopCubic(cubics, top);
     SkPoint left[SkPatch::kNumPtsCubic];
-    patch.getLeftPoints(left);
+    SkPatchUtils::getLeftCubic(cubics, left);
     SkPoint right[SkPatch::kNumPtsCubic];
-    patch.getRightPoints(right);
+    SkPatchUtils::getRightCubic(cubics, right);
 
     paint.setColor(SK_ColorBLACK);
     paint.setStrokeWidth(0.5);
     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, 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);
+    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(2);
 
@@ -47,16 +60,16 @@ static void draw_control_points(SkCanvas* canvas, const SkPatch& patch) {
     canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
 
     paint.setColor(SK_ColorBLUE);
-    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom+1, paint);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint);
 
     paint.setColor(SK_ColorCYAN);
-    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top+1, paint);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint);
 
     paint.setColor(SK_ColorYELLOW);
-    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left+1, paint);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint);
 
     paint.setColor(SK_ColorGREEN);
-    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right+1, paint);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint);
 }
 
 namespace skiagm {
@@ -88,44 +101,63 @@ protected:
         SkPaint paint;
         
         // The order of the colors and points is clockwise starting at upper-left corner.
-        SkColor colors[SkPatch::kNumColors] = {
-            SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
-        };
-        SkPoint points[SkPatch::kNumCtrlPts] = {
+        const SkPoint cubics[SkPatch::kNumCtrlPts] = {
             //top points
-            {50,50},{75,20},{125,80}, {150,50},
+            {100,100},{150,50},{250,150}, {300,100},
             //right points
-            {120,75},{180,125},
+            {250, 150},{350,250},
             //bottom points
-            {150,150},{125,120},{75,180},{50,150},
+            {300,300},{250,250},{150,350},{100,300},
             //left points
-            {20,125},{80,75}
+            {50,250},{150,150}
         };
         
-        SkPatch patch(points, colors);
-        static const SkScalar kScale = 0.5f;
-        canvas->translate(100, 100);
-        canvas->save();
-        for (SkScalar x = 0; x < 4; x++) {
-            canvas->save();
-            canvas->scale(kScale * (x + 1), kScale * (x + 1));
-            canvas->translate(x * 100, 0);
-            canvas->drawPatch(patch, paint);
-            draw_control_points(canvas, patch);
-            canvas->restore();
-        }
+        const SkColor colors[SkPatch::kNumCorners] = {
+            SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
+        };
+        const SkPoint texCoords[SkPatch::kNumCorners] = {
+            {0.0f, 0.0f}, {100.0f, 0.0f}, {100.0f,100.0f}, {0.0f, 100.0f}}
+        ;
         
-        canvas->translate(0, 270);
+        const SkXfermode::Mode modes[] = {
+            SkXfermode::kSrc_Mode,
+            SkXfermode::kDst_Mode,
+            SkXfermode::kModulate_Mode,
+        };
         
-        static const SkScalar kSkew = 0.2f;
-        for (SkScalar x = 0; x < 4; x++) {
-            canvas->save();
-            canvas->scale(kScale * (x + 1), kScale * (x + 1));
-            canvas->translate(x * 100, 0);
-            canvas->skew(kSkew * (x + 1), kSkew * (x + 1));
-            canvas->drawPatch(patch, paint);
-            draw_control_points(canvas, patch);
-            canvas->restore();
+        SkAutoTUnref<SkShader> shader(make_shader());
+        
+        canvas->save();
+        for (int y = 0; y < 3; y++) {
+            SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(modes[y]));
+
+            for (int x = 0; x < 4; x++) {
+                canvas->save();
+                canvas->translate(x * 350, y * 350);
+                switch (x) {
+                    case 0:
+                        canvas->drawPatch(cubics, NULL, NULL, xfer, paint);
+                        break;
+                    case 1:
+                        canvas->drawPatch(cubics, colors, NULL, xfer, paint);
+                        break;
+                    case 2:
+                        paint.setShader(shader);
+                        canvas->drawPatch(cubics, NULL, texCoords, xfer, paint);
+                        paint.setShader(NULL);
+                        break;
+                    case 3:
+                        paint.setShader(shader);
+                        canvas->drawPatch(cubics, colors, texCoords, xfer, paint);
+                        paint.setShader(NULL);
+                        break;
+                    default:
+                        break;
+                }
+                
+                draw_control_points(canvas, cubics);
+                canvas->restore();
+            }
         }
         canvas->restore();
     }