WIP: GPU-accelerated trapezoidal path renderer.

src/core/SkEdge.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkEdge.h"
@@ skipping 56 matching lines @@
     }
     // are we completely above or below the clip?
     if (clip && (top >= clip->fBottom || bot <= clip->fTop)) {
         return 0;
     }
 
     SkFixed slope = SkFDot6Div(x1 - x0, y1 - y0);
     const SkFDot6 dy  = SkEdge_Compute_DY(top, y0);
 
     fX          = SkFDot6ToFixed(x0 + SkFixedMul(slope, dy));   // + SK_Fixed1/2
+    fFirstXf    = winding < 0 ? p1.fX : p0.fX;
     fDX         = slope;
     fFirstY     = top;
+    fFirstYf    = static_cast<float>(top);
     fLastY      = bot - 1;
     fCurveCount = 0;
     fWinding    = SkToS8(winding);
     fCurveShift = 0;
 
     if (clip) {
         this->chopLineWithClip(*clip);
     }
     return 1;
 }
@@ skipping 170 matching lines @@
 
     A = SkFDot6ToFixedDiv2(y0 - y1 - y1 + y2);  // 1/2 the real value
     B = SkFDot6ToFixed(y1 - y0);                // 1/2 the real value
 
     fQy     = SkFDot6ToFixed(y0);
     fQDy    = B + (A >> shift);     // biased by shift
     fQDDy   = A >> (shift - 1);     // biased by shift
 
     fQLastX = SkFDot6ToFixed(x2);
     fQLastY = SkFDot6ToFixed(y2);
+    fFirstXf    = winding < 0 ? pts[2].fX : pts[0].fX;
+    fFirstYf    = static_cast<float>(top);
 
     return this->updateQuadratic();
 }
 
 int SkQuadraticEdge::updateQuadratic()
 {
     int     success;
     int     count = fCurveCount;
     SkFixed oldx = fQx;
     SkFixed oldy = fQy;
@@ skipping 142 matching lines @@
     D = SkFDot6UpShift(y3 + 3 * (y1 - y2) - y0, upShift);
 
     fCy     = SkFDot6ToFixed(y0);
     fCDy    = B + (C >> shift) + (D >> 2*shift);    // biased by shift
     fCDDy   = 2*C + (3*D >> (shift - 1));           // biased by 2*shift
     fCDDDy  = 3*D >> (shift - 1);                   // biased by 2*shift
 
     fCLastX = SkFDot6ToFixed(x3);
     fCLastY = SkFDot6ToFixed(y3);
 
+    fFirstXf    = winding < 0 ? pts[3].fX : pts[0].fX;
+    fFirstYf    = static_cast<float>(top);
     return this->updateCubic();
 }
 
 int SkCubicEdge::updateCubic()
 {
     int     success;
     int     count = fCurveCount;
     SkFixed oldx = fCx;
     SkFixed oldy = fCy;
     SkFixed newx, newy;
@@ skipping 29 matching lines @@
         success = this->updateLine(oldx, oldy, newx, newy);
         oldx = newx;
         oldy = newy;
     } while (count < 0 && !success);
 
     fCx         = newx;
     fCy         = newy;
     fCurveCount = SkToS8(count);
     return success;
 }