1 files changed, 84 insertions, 0 deletions
diff --git a/chromium/third_party/skia/experimental/SkSetPoly3To3_A.cpp b/chromium/third_party/skia/experimental/SkSetPoly3To3_A.cpp
new file mode 100644
index 00000000000..18777a77b5b
--- /dev/null
+++ b/chromium/third_party/skia/experimental/SkSetPoly3To3_A.cpp
@@ -0,0 +1,84 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SkMatrix.h"
+
+// FIXME: needs to be in a header
+bool SkSetPoly3To3_A(SkMatrix* matrix, const SkPoint src[3], const SkPoint dst[3]);
+
+typedef double SkDScalar;
+
+static SkScalar SkDScalar_toScalar(SkDScalar value) {
+    return static_cast<float>(value);
+}
+static SkScalar divide(SkDScalar numer, SkDScalar denom) {
+    return static_cast<float>(numer / denom);
+}
+
+static SkDScalar SkDScalar_setMul(SkScalar a, SkScalar b) {
+    return (SkDScalar) ((SkDScalar) a * b);
+}
+
+static void computeOuterProduct(SkScalar op[4],
+                                const SkPoint pts0[3], const SkPoint& ave0,
+                                const SkPoint pts1[3], const SkPoint& ave1) {
+    sk_bzero(op, 4 * sizeof(op[0]));
+    for (int i = 0; i < 3; i++) {
+        SkScalar x0 = pts0[i].fX - ave0.fX;
+        SkScalar y0 = pts0[i].fY - ave0.fY;
+        SkScalar x1 = pts1[i].fX - ave1.fX;
+        SkScalar y1 = pts1[i].fY - ave1.fY;
+        op[0] += SkScalarMul(x0, x1);
+        op[1] += SkScalarMul(x0, y1);
+        op[2] += SkScalarMul(y0, x1);
+        op[3] += SkScalarMul(y0, y1);
+    }
+}
+
+static SkDScalar ddot(SkScalar ax, SkScalar ay, SkScalar bx, SkScalar by) {
+    return SkDScalar_setMul(ax, bx) + SkDScalar_setMul(ay, by);
+}
+
+static SkScalar dot(SkScalar ax, SkScalar ay, SkScalar bx, SkScalar by) {
+    return SkDScalar_toScalar(ddot(ax, ay, bx, by));
+}
+
+bool SkSetPoly3To3_A(SkMatrix* matrix, const SkPoint src[3], const SkPoint dst[3]) {
+    const SkPoint& srcAve = src[0];
+    const SkPoint& dstAve = dst[0];
+
+    SkScalar srcOP[4], dstOP[4];
+
+    computeOuterProduct(srcOP, src, srcAve, src, srcAve);
+    computeOuterProduct(dstOP, src, srcAve, dst, dstAve);
+
+    SkDScalar det = SkDScalar_setMul(srcOP[0], srcOP[3]) -
+                    SkDScalar_setMul(srcOP[1], srcOP[2]);
+
+    SkDScalar M[4];
+
+    const SkScalar srcOP0 = srcOP[3];
+    const SkScalar srcOP1 = -srcOP[1];
+    const SkScalar srcOP2 = -srcOP[2];
+    const SkScalar srcOP3 = srcOP[0];
+
+    M[0] = ddot(srcOP0, srcOP1, dstOP[0], dstOP[2]);
+    M[1] = ddot(srcOP2, srcOP3, dstOP[0], dstOP[2]);
+    M[2] = ddot(srcOP0, srcOP1, dstOP[1], dstOP[3]);
+    M[3] = ddot(srcOP2, srcOP3, dstOP[1], dstOP[3]);
+
+    matrix->reset();
+    matrix->setScaleX(divide(M[0], det));
+    matrix->setSkewX( divide(M[1], det));
+    matrix->setSkewY (divide(M[2], det));
+    matrix->setScaleY(divide(M[3], det));
+    matrix->setTranslateX(dstAve.fX - dot(srcAve.fX, srcAve.fY,
+                                    matrix->getScaleX(), matrix->getSkewX()));
+    matrix->setTranslateY(dstAve.fY - dot(srcAve.fX, srcAve.fY,
+                                    matrix->getSkewY(), matrix->getScaleY()));
+    return true;
+}