convert mapHomogeneousPoints to SkPoint3

SkMatrix::mapHomogeneousPoints takes an array of SkScalar,
but expects essentially SkPoint3, so make it so.


R: robertphillips@google.com, reed@google.com
Bug: skia:6898
Change-Id: Ibaf8b05c08b7df16c67d6a77d914667ace9a70da
Reviewed-on: https://skia-review.googlesource.com/58380
Commit-Queue: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>

2 files changed, 22 insertions, 30 deletions

diff --git a/src/core/SkGeometry.cpp b/src/core/SkGeometry.cpp
index 0b3eedab17..6a5207b9ed 100644
--- a/src/core/SkGeometry.cpp
+++ b/src/core/SkGeometry.cpp
@@ -8,6 +8,7 @@
 #include "SkGeometry.h"
 #include "SkMatrix.h"
 #include "SkNx.h"
+#include "SkPoint3.h"
 
 static SkVector to_vector(const Sk2s& x) {
     SkVector vector;
@@ -974,18 +975,6 @@ static bool conic_find_extrema(const SkScalar src[], SkScalar w, SkScalar* t) {
     return false;
 }
 
-struct SkP3D {
-    SkScalar fX, fY, fZ;
-
-    void set(SkScalar x, SkScalar y, SkScalar z) {
-        fX = x; fY = y; fZ = z;
-    }
-
-    void projectDown(SkPoint* dst) const {
-        dst->set(fX / fZ, fY / fZ);
-    }
-};
-
 // We only interpolate one dimension at a time (the first, at +0, +3, +6).
 static void p3d_interp(const SkScalar src[7], SkScalar dst[7], SkScalar t) {
     SkScalar ab = SkScalarInterp(src[0], src[3], t);
@@ -995,15 +984,19 @@ static void p3d_interp(const SkScalar src[7], SkScalar dst[7], SkScalar t) {
     dst[6] = bc;
 }
 
-static void ratquad_mapTo3D(const SkPoint src[3], SkScalar w, SkP3D dst[]) {
+static void ratquad_mapTo3D(const SkPoint src[3], SkScalar w, SkPoint3 dst[3]) {
     dst[0].set(src[0].fX * 1, src[0].fY * 1, 1);
     dst[1].set(src[1].fX * w, src[1].fY * w, w);
     dst[2].set(src[2].fX * 1, src[2].fY * 1, 1);
 }
 
+static SkPoint project_down(const SkPoint3& src) {
+    return {src.fX / src.fZ, src.fY / src.fZ};
+}
+
 // return false if infinity or NaN is generated; caller must check
 bool SkConic::chopAt(SkScalar t, SkConic dst[2]) const {
-    SkP3D tmp[3], tmp2[3];
+    SkPoint3 tmp[3], tmp2[3];
 
     ratquad_mapTo3D(fPts, fW, tmp);
 
@@ -1012,9 +1005,9 @@ bool SkConic::chopAt(SkScalar t, SkConic dst[2]) const {
     p3d_interp(&tmp[0].fZ, &tmp2[0].fZ, t);
 
     dst[0].fPts[0] = fPts[0];
-    tmp2[0].projectDown(&dst[0].fPts[1]);
-    tmp2[1].projectDown(&dst[0].fPts[2]); dst[1].fPts[0] = dst[0].fPts[2];
-    tmp2[2].projectDown(&dst[1].fPts[1]);
+    dst[0].fPts[1] = project_down(tmp2[0]);
+    dst[0].fPts[2] = project_down(tmp2[1]); dst[1].fPts[0] = dst[0].fPts[2];
+    dst[1].fPts[1] = project_down(tmp2[2]);
     dst[1].fPts[2] = fPts[2];
 
     // to put in "standard form", where w0 and w2 are both 1, we compute the
@@ -1341,11 +1334,11 @@ SkScalar SkConic::TransformW(const SkPoint pts[], SkScalar w,
         return w;
     }
 
-    SkP3D src[3], dst[3];
+    SkPoint3 src[3], dst[3];
 
     ratquad_mapTo3D(pts, w, src);
 
-    matrix.mapHomogeneousPoints(&dst[0].fX, &src[0].fX, 3);
+    matrix.mapHomogeneousPoints(dst, src, 3);
 
     // w' = sqrt(w1*w1/w0*w2)
     SkScalar w0 = dst[0].fZ;
diff --git a/src/core/SkMatrix.cpp b/src/core/SkMatrix.cpp
index 5b1be84588..89bde4b42c 100644
--- a/src/core/SkMatrix.cpp
+++ b/src/core/SkMatrix.cpp
@@ -9,6 +9,7 @@
 #include "SkMatrix.h"
 #include "SkNx.h"
 #include "SkPaint.h"
+#include "SkPoint3.h"
 #include "SkRSXform.h"
 #include "SkString.h"
 #include <stddef.h>
@@ -1036,30 +1037,28 @@ const SkMatrix::MapPtsProc SkMatrix::gMapPtsProcs[] = {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkMatrix::mapHomogeneousPoints(SkScalar dst[], const SkScalar src[], int count) const {
+void SkMatrix::mapHomogeneousPoints(SkPoint3 dst[], const SkPoint3 src[], int count) const {
     SkASSERT((dst && src && count > 0) || 0 == count);
     // no partial overlap
-    SkASSERT(src == dst || &dst[3*count] <= &src[0] || &src[3*count] <= &dst[0]);
+    SkASSERT(src == dst || &dst[count] <= &src[0] || &src[count] <= &dst[0]);
 
     if (count > 0) {
         if (this->isIdentity()) {
-            memcpy(dst, src, 3*count*sizeof(SkScalar));
+            memcpy(dst, src, count * sizeof(SkPoint3));
             return;
         }
         do {
-            SkScalar sx = src[0];
-            SkScalar sy = src[1];
-            SkScalar sw = src[2];
-            src += 3;
+            SkScalar sx = src->fX;
+            SkScalar sy = src->fY;
+            SkScalar sw = src->fZ;
+            src++;
 
             SkScalar x = sdot(sx, fMat[kMScaleX], sy, fMat[kMSkewX],  sw, fMat[kMTransX]);
             SkScalar y = sdot(sx, fMat[kMSkewY],  sy, fMat[kMScaleY], sw, fMat[kMTransY]);
             SkScalar w = sdot(sx, fMat[kMPersp0], sy, fMat[kMPersp1], sw, fMat[kMPersp2]);
 
-            dst[0] = x;
-            dst[1] = y;
-            dst[2] = w;
-            dst += 3;
+            dst->set(x, y, w);
+            dst++;
         } while (--count);
     }
 }