move boundarypatch into utils

git-svn-id: http://skia.googlecode.com/svn/trunk@410 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 73 insertions, 0 deletions

diff --git a/src/utils/SkBoundaryPatch.cpp b/src/utils/SkBoundaryPatch.cpp
new file mode 100644
index 0000000000..cdbc877634
--- /dev/null
+++ b/src/utils/SkBoundaryPatch.cpp
@@ -0,0 +1,73 @@
+#include "SkBoundaryPatch.h"
+
+SkBoundaryPatch::SkBoundaryPatch() : fBoundary(NULL) {}
+
+SkBoundaryPatch::~SkBoundaryPatch() {
+    SkSafeUnref(fBoundary);
+}
+
+SkBoundary* SkBoundaryPatch::setBoundary(SkBoundary* b) {
+    SkRefCnt_SafeAssign(fBoundary, b);
+    return b;
+}
+
+static SkPoint SkMakePoint(SkScalar x, SkScalar y) {
+    SkPoint pt;
+    pt.set(x, y);
+    return pt;
+}
+
+static SkPoint SkPointInterp(const SkPoint& a, const SkPoint& b, SkScalar t) {
+    return SkMakePoint(SkScalarInterp(a.fX, b.fX, t),
+                       SkScalarInterp(a.fY, b.fY, t));
+}
+
+SkPoint SkBoundaryPatch::eval(SkScalar unitU, SkScalar unitV) {
+    SkBoundary* b = fBoundary;
+    SkPoint u = SkPointInterp(b->eval(SkBoundary::kLeft, SK_Scalar1 - unitV),
+                              b->eval(SkBoundary::kRight, unitV),
+                              unitU);
+    SkPoint v = SkPointInterp(b->eval(SkBoundary::kTop, unitU),
+                              b->eval(SkBoundary::kBottom, SK_Scalar1 - unitU),
+                              unitV);
+    return SkMakePoint(SkScalarAve(u.fX, v.fX),
+                       SkScalarAve(u.fY, v.fY));
+}
+
+bool SkBoundaryPatch::evalPatch(SkPoint verts[], int rows, int cols) {
+    if (rows < 2 || cols < 2) {
+        return false;
+    }
+
+    const SkScalar invR = SkScalarInvert(SkIntToScalar(rows - 1));
+    const SkScalar invC = SkScalarInvert(SkIntToScalar(cols - 1));
+    
+    for (int y = 0; y < cols; y++) {
+        SkScalar yy = y * invC;
+        for (int x = 0; x < rows; x++) {
+            *verts++ = this->eval(x * invR, yy);
+        }
+    }
+    return true;
+}
+
+////////////////////////////////////////////////////////////////////////
+
+#include "SkGeometry.h"
+
+SkPoint SkLineBoundary::eval(Edge e, SkScalar t) {
+    SkASSERT((unsigned)e < 4);
+    return SkPointInterp(fPts[e], fPts[(e + 1) & 3], t);
+}
+
+SkPoint SkCubicBoundary::eval(Edge e, SkScalar t) {
+    SkASSERT((unsigned)e < 4);
+
+    // ensure our 4th cubic wraps to the start of the first
+    fPts[12] = fPts[0];
+
+    SkPoint loc;
+    SkEvalCubicAt(&fPts[e * 3], t, &loc, NULL, NULL);
+    return loc;
+}
+