From 5cf2c28427c1e8eaf464aaedddc1c9c73f2475ae Mon Sep 17 00:00:00 2001
From: "rileya@google.com"
 <rileya@google.com@2bbb7eff-a529-9590-31e7-b0007b416f81>
Date: Mon, 9 Jul 2012 14:42:16 +0000
Subject: [PATCH] Added conical gradient to gm gradients test, and added two
 variants of that test, one with perspective applied to the local matrices of
 the gradients and the other with perspective applied to the overall view
 matrix.

Will require GM rebaselining.
Review URL: https://codereview.appspot.com/6344091

git-svn-id: http://skia.googlecode.com/svn/trunk@4468 2bbb7eff-a529-9590-31e7-b0007b416f81
---
 gm/gradients.cpp | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 100 insertions(+), 2 deletions(-)

diff --git a/gm/gradients.cpp b/gm/gradients.cpp
index ad745df..9336052 100644
--- a/gm/gradients.cpp
+++ b/gm/gradients.cpp
@@ -70,10 +70,23 @@ static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data,
                                                   data.fColors, data.fPos, data.fCount, tm, mapper);
 }
 
+static SkShader* Make2Conical(const SkPoint pts[2], const GradData& data,
+                             SkShader::TileMode tm, SkUnitMapper* mapper) {
+    SkPoint center0, center1;
+    SkScalar radius0 = SkScalarDiv(pts[1].fX - pts[0].fX, 10);
+    SkScalar radius1 = SkScalarDiv(pts[1].fX - pts[0].fX, 3);
+    center0.set(pts[0].fX + radius0, pts[0].fY + radius0);
+    center1.set(pts[1].fX - radius1, pts[1].fY - radius1);
+    return SkGradientShader::CreateTwoPointConical(center1, radius1, 
+                                                   center0, radius0, 
+                                                   data.fColors, data.fPos, 
+                                                   data.fCount, tm, mapper);
+}
+
 typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data,
                                SkShader::TileMode tm, SkUnitMapper* mapper);
 static const GradMaker gGradMakers[] = {
-    MakeLinear, MakeRadial, MakeSweep, Make2Radial
+    MakeLinear, MakeRadial, MakeSweep, Make2Radial, Make2Conical
 };
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -89,7 +102,7 @@ protected:
         return SkString("gradients");
     }
     
-    virtual SkISize onISize() { return make_isize(640, 510); }
+    virtual SkISize onISize() { return make_isize(640, 615); }
         
     virtual void onDraw(SkCanvas* canvas) {
         
@@ -121,6 +134,84 @@ private:
     typedef GM INHERITED;
 };
 
+// Based on the original gradient slide, but with perspective applied to the
+// gradient shaders' local matrices
+class GradientsLocalPerspectiveGM : public GM {
+public:
+	GradientsLocalPerspectiveGM() {
+        this->setBGColor(0xFFDDDDDD);
+    }
+    
+protected:
+    SkString onShortName() {
+        return SkString("gradients_local_perspective");
+    }
+    
+    virtual SkISize onISize() { return make_isize(640, 615); }
+        
+    virtual void onDraw(SkCanvas* canvas) {
+        
+        SkPoint pts[2] = {
+            { 0, 0 },
+            { SkIntToScalar(100), SkIntToScalar(100) }
+        };
+        SkShader::TileMode tm = SkShader::kClamp_TileMode;
+        SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        
+        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
+            canvas->save();
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
+                SkShader* shader = gGradMakers[j](pts, gGradData[i], tm, NULL);
+                
+                // apply an increasing y perspective as we move to the right
+                SkMatrix perspective;
+                perspective.setIdentity();
+                perspective.setPerspY(SkScalarDiv(SkIntToScalar(i+1),
+                                      SkIntToScalar(500)));
+                perspective.setSkewX(SkScalarDiv(SkIntToScalar(i+1),
+                                     SkIntToScalar(10)));
+                shader->setLocalMatrix(perspective);
+
+                paint.setShader(shader);
+                canvas->drawRect(r, paint);
+                shader->unref();
+                canvas->translate(0, SkIntToScalar(120));
+            }
+            canvas->restore();
+            canvas->translate(SkIntToScalar(120), 0);
+        }
+    }
+    
+private:
+    typedef GM INHERITED;
+};
+
+// Based on the original gradient slide, but with perspective applied to
+// the view matrix
+class GradientsViewPerspectiveGM : public GradientsGM {
+protected:
+    SkString onShortName() {
+        return SkString("gradients_view_perspective");
+    }
+    
+    virtual SkISize onISize() { return make_isize(640, 400); }
+        
+    virtual void onDraw(SkCanvas* canvas) {
+        SkMatrix perspective;
+        perspective.setIdentity();
+        perspective.setPerspY(SkScalarDiv(SK_Scalar1, SkIntToScalar(1000)));
+        perspective.setSkewX(SkScalarDiv(SkIntToScalar(8), SkIntToScalar(25)));
+        canvas->setMatrix(perspective);
+        INHERITED::onDraw(canvas);
+    }
+    
+private:
+    typedef GradientsGM INHERITED;
+};
+
 /*
  Inspired by this <canvas> javascript, where we need to detect that we are not
  solving a quadratic equation, but must instead solve a linear (since our X^2
@@ -269,5 +360,12 @@ static GMRegistry reg3(MyFactory3);
 
 static GM* MyFactory4(void*) { return new RadialGradientGM; }
 static GMRegistry reg4(MyFactory4);
+
+static GM* MyFactory5(void*) { return new GradientsLocalPerspectiveGM; }
+static GMRegistry reg5(MyFactory5);
+
+static GM* MyFactory6(void*) { return new GradientsViewPerspectiveGM; }
+static GMRegistry reg6(MyFactory6);
 }
 
+
-- 
2.7.4