Allow compiler to optimize applying quadratic UV matrix to verts
Code Review: http://codereview.appspot.com/5833048/
git-svn-id: http://skia.googlecode.com/svn/trunk@3398 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrPathUtils.cpp b/src/gpu/GrPathUtils.cpp
index c32ee8e..cecc514 100644
--- a/src/gpu/GrPathUtils.cpp
+++ b/src/gpu/GrPathUtils.cpp
@@ -187,44 +187,13 @@
return pointCount;
}
-namespace {
-// The matrix computed for quadDesignSpaceToUVCoordsMatrix should never really
-// have perspective and we really want to avoid perspective matrix muls.
-// However, the first two entries of the perspective row may be really close to
-// 0 and the third may not be 1 due to a scale on the entire matrix.
-inline void fixup_matrix(GrMatrix* mat) {
-#ifndef SK_SCALAR_IS_FLOAT
- GrCrash("Expected scalar is float.");
-#endif
- static const GrScalar gTOL = 1.f / 100.f;
- GrAssert(GrScalarAbs(mat->get(SkMatrix::kMPersp0)) < gTOL);
- GrAssert(GrScalarAbs(mat->get(SkMatrix::kMPersp1)) < gTOL);
- float m33 = mat->get(SkMatrix::kMPersp2);
- if (1.f != m33) {
- m33 = 1.f / m33;
- mat->setAll(m33 * mat->get(SkMatrix::kMScaleX),
- m33 * mat->get(SkMatrix::kMSkewX),
- m33 * mat->get(SkMatrix::kMTransX),
- m33 * mat->get(SkMatrix::kMSkewY),
- m33 * mat->get(SkMatrix::kMScaleY),
- m33 * mat->get(SkMatrix::kMTransY),
- 0.f, 0.f, 1.f);
- } else {
- mat->setPerspX(0);
- mat->setPerspY(0);
- }
-}
-}
-
-// Compute a matrix that goes from the 2d space coordinates to UV space where
-// u^2-v = 0 specifies the quad.
-void GrPathUtils::quadDesignSpaceToUVCoordsMatrix(const SkPoint qPts[3],
- GrMatrix* matrix) {
+void GrPathUtils::QuadUVMatrix::set(const GrPoint qPts[3]) {
// can't make this static, no cons :(
SkMatrix UVpts;
#ifndef SK_SCALAR_IS_FLOAT
GrCrash("Expected scalar is float.");
#endif
+ SkMatrix m;
// We want M such that M * xy_pt = uv_pt
// We know M * control_pts = [0 1/2 1]
// [0 0 1]
@@ -233,10 +202,10 @@
UVpts.setAll(0, 0.5f, 1.f,
0, 0, 1.f,
1.f, 1.f, 1.f);
- matrix->setAll(qPts[0].fX, qPts[1].fX, qPts[2].fX,
- qPts[0].fY, qPts[1].fY, qPts[2].fY,
- 1.f, 1.f, 1.f);
- if (!matrix->invert(matrix)) {
+ m.setAll(qPts[0].fX, qPts[1].fX, qPts[2].fX,
+ qPts[0].fY, qPts[1].fY, qPts[2].fY,
+ 1.f, 1.f, 1.f);
+ if (!m.invert(&m)) {
// The quad is degenerate. Hopefully this is rare. Find the pts that are
// farthest apart to compute a line (unless it is really a pt).
SkScalar maxD = qPts[0].distanceToSqd(qPts[1]);
@@ -260,19 +229,46 @@
// case.
lineVec.setOrthog(lineVec, GrPoint::kLeft_Side);
lineVec.dot(qPts[0]);
- matrix->setAll(0, 0, 0,
- lineVec.fX, lineVec.fY, -lineVec.dot(qPts[maxEdge]),
- 0, 0, 1.f);
+ // first row
+ fM[0] = 0;
+ fM[1] = 0;
+ fM[2] = 0;
+ // second row
+ fM[3] = lineVec.fX;
+ fM[4] = lineVec.fY;
+ fM[5] = -lineVec.dot(qPts[maxEdge]);
} else {
// It's a point. It should cover zero area. Just set the matrix such
// that (u, v) will always be far away from the quad.
- matrix->setAll(0, 0, 100 * SK_Scalar1,
- 0, 0, 100 * SK_Scalar1,
- 0, 0, 1.f);
+ fM[0] = 0; fM[1] = 0; fM[2] = 100.f;
+ fM[3] = 0; fM[4] = 0; fM[5] = 100.f;
}
} else {
- matrix->postConcat(UVpts);
- fixup_matrix(matrix);
+ m.postConcat(UVpts);
+
+ // The matrix should not have perspective.
+ static const GrScalar gTOL = 1.f / 100.f;
+ GrAssert(GrScalarAbs(m.get(SkMatrix::kMPersp0)) < gTOL);
+ GrAssert(GrScalarAbs(m.get(SkMatrix::kMPersp1)) < gTOL);
+
+ // It may not be normalized to have 1.0 in the bottom right
+ float m33 = m.get(SkMatrix::kMPersp2);
+ if (1.f != m33) {
+ m33 = 1.f / m33;
+ fM[0] = m33 * m.get(SkMatrix::kMScaleX);
+ fM[1] = m33 * m.get(SkMatrix::kMSkewX);
+ fM[2] = m33 * m.get(SkMatrix::kMTransX);
+ fM[3] = m33 * m.get(SkMatrix::kMSkewY);
+ fM[4] = m33 * m.get(SkMatrix::kMScaleY);
+ fM[5] = m33 * m.get(SkMatrix::kMTransY);
+ } else {
+ fM[0] = m.get(SkMatrix::kMScaleX);
+ fM[1] = m.get(SkMatrix::kMSkewX);
+ fM[2] = m.get(SkMatrix::kMTransX);
+ fM[3] = m.get(SkMatrix::kMSkewY);
+ fM[4] = m.get(SkMatrix::kMScaleY);
+ fM[5] = m.get(SkMatrix::kMTransY);
+ }
}
}