diff options
author | mike@reedtribe.org <mike@reedtribe.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2012-07-11 01:51:33 +0000 |
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committer | mike@reedtribe.org <mike@reedtribe.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2012-07-11 01:51:33 +0000 |
commit | bad1b2ff1d34ff86693b776f89d7b46995746127 (patch) | |
tree | c101051386499f04dfe422ab635d20533eff8d7b /src/utils | |
parent | 927ee823fc8789140184ffcf342d434e159413a1 (diff) |
add SkPath::contains(x, y)
git-svn-id: http://skia.googlecode.com/svn/trunk@4526 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/utils')
-rw-r--r-- | src/utils/SkCullPoints.cpp | 251 |
1 files changed, 0 insertions, 251 deletions
diff --git a/src/utils/SkCullPoints.cpp b/src/utils/SkCullPoints.cpp index a8ec39b042..3e3082f0c0 100644 --- a/src/utils/SkCullPoints.cpp +++ b/src/utils/SkCullPoints.cpp @@ -218,254 +218,3 @@ bool SkHitTestPath(const SkPath& path, SkScalar x, SkScalar y, bool hires) { return SkHitTestPath(path, r, hires); } -/////////////////////////////////////////////////////////////////////////////// - -#include "SkGeometry.h" - -static SkScalar eval_cubic_coeff(SkScalar A, SkScalar B, SkScalar C, - SkScalar D, SkScalar t) { - return SkScalarMulAdd(SkScalarMulAdd(SkScalarMulAdd(A, t, B), t, C), t, D); -} - -static SkScalar eval_cubic_pts(SkScalar c0, SkScalar c1, SkScalar c2, SkScalar c3, - SkScalar t) { - SkScalar A = c3 + 3*(c1 - c2) - c0; - SkScalar B = 3*(c2 - c1 - c1 + c0); - SkScalar C = 3*(c1 - c0); - SkScalar D = c0; - return eval_cubic_coeff(A, B, C, D, t); -} - -/* Given 4 cubic points (either Xs or Ys), and a target X or Y, compute the - t value such that cubic(t) = target - */ -static bool chopMonoCubicAt(SkScalar c0, SkScalar c1, SkScalar c2, SkScalar c3, - SkScalar target, SkScalar* t) { -// SkASSERT(c0 <= c1 && c1 <= c2 && c2 <= c3); - SkASSERT(c0 < target && target < c3); - - SkScalar D = c0 - target; - SkScalar A = c3 + 3*(c1 - c2) - c0; - SkScalar B = 3*(c2 - c1 - c1 + c0); - SkScalar C = 3*(c1 - c0); - - const SkScalar TOLERANCE = SK_Scalar1 / 4096; - SkScalar minT = 0; - SkScalar maxT = SK_Scalar1; - SkScalar mid; - int i; - for (i = 0; i < 16; i++) { - mid = SkScalarAve(minT, maxT); - SkScalar delta = eval_cubic_coeff(A, B, C, D, mid); - if (delta < 0) { - minT = mid; - delta = -delta; - } else { - maxT = mid; - } - if (delta < TOLERANCE) { - break; - } - } - *t = mid; - return true; -} - -template <size_t N> static void find_minmax(const SkPoint pts[], - SkScalar* minPtr, SkScalar* maxPtr) { - SkScalar min, max; - min = max = pts[0].fX; - for (size_t i = 1; i < N; ++i) { - min = SkMinScalar(min, pts[i].fX); - max = SkMaxScalar(max, pts[i].fX); - } - *minPtr = min; - *maxPtr = max; -} - -static int winding_mono_cubic(const SkPoint pts[], SkScalar x, SkScalar y) { - SkPoint storage[4]; - - int dir = 1; - if (pts[0].fY > pts[3].fY) { - storage[0] = pts[3]; - storage[1] = pts[2]; - storage[2] = pts[1]; - storage[3] = pts[0]; - pts = storage; - dir = -1; - } - if (y < pts[0].fY || y >= pts[3].fY) { - return 0; - } - - // quickreject or quickaccept - SkScalar min, max; - find_minmax<4>(pts, &min, &max); - if (x < min) { - return 0; - } - if (x > max) { - return dir; - } - - // compute the actual x(t) value - SkScalar t, xt; - if (chopMonoCubicAt(pts[0].fY, pts[1].fY, pts[2].fY, pts[3].fY, y, &t)) { - xt = eval_cubic_pts(pts[0].fX, pts[1].fX, pts[2].fX, pts[3].fX, t); - } else { - SkScalar mid = SkScalarAve(pts[0].fY, pts[3].fY); - xt = y < mid ? pts[0].fX : pts[3].fX; - } - return xt < x ? dir : 0; -} - -static int winding_cubic(const SkPoint pts[], SkScalar x, SkScalar y) { - SkPoint dst[10]; - int n = SkChopCubicAtYExtrema(pts, dst); - int w = 0; - for (int i = 0; i <= n; ++i) { - w += winding_mono_cubic(&dst[i * 3], x, y); - } - return w; -} - -static int winding_mono_quad(const SkPoint pts[], SkScalar x, SkScalar y) { - SkScalar y0 = pts[0].fY; - SkScalar y2 = pts[2].fY; - - int dir = 1; - if (y0 > y2) { - SkTSwap(y0, y2); - dir = -1; - } - if (y < y0 || y >= y2) { - return 0; - } - - // bounds check on X (not required, but maybe faster) -#if 0 - if (pts[0].fX > x && pts[1].fX > x && pts[2].fX > x) { - return 0; - } -#endif - - SkScalar roots[2]; - int n = SkFindUnitQuadRoots(pts[0].fY - 2 * pts[1].fY + pts[2].fY, - 2 * (pts[1].fY - pts[0].fY), - pts[0].fY - y, - roots); - SkASSERT(n <= 1); - SkScalar xt; - if (0 == n) { - SkScalar mid = SkScalarAve(y0, y2); - // Need [0] and [2] if dir == 1 - // and [2] and [0] if dir == -1 - xt = y < mid ? pts[1 - dir].fX : pts[dir - 1].fX; - } else { - SkScalar t = roots[0]; - SkScalar C = pts[0].fX; - SkScalar A = pts[2].fX - 2 * pts[1].fX + C; - SkScalar B = 2 * (pts[1].fX - C); - xt = SkScalarMulAdd(SkScalarMulAdd(A, t, B), t, C); - } - return xt < x ? dir : 0; -} - -static bool is_mono_quad(SkScalar y0, SkScalar y1, SkScalar y2) { -// return SkScalarSignAsInt(y0 - y1) + SkScalarSignAsInt(y1 - y2) != 0; - if (y0 == y1) { - return true; - } - if (y0 < y1) { - return y1 <= y2; - } else { - return y1 >= y2; - } -} - -static int winding_quad(const SkPoint pts[], SkScalar x, SkScalar y) { - SkPoint dst[5]; - int n = 0; - - if (!is_mono_quad(pts[0].fY, pts[1].fY, pts[2].fY)) { - n = SkChopQuadAtYExtrema(pts, dst); - pts = dst; - } - int w = winding_mono_quad(pts, x, y); - if (n > 0) { - w += winding_mono_quad(&pts[2], x, y); - } - return w; -} - -static int winding_line(const SkPoint pts[], SkScalar x, SkScalar y) { - SkScalar x0 = pts[0].fX; - SkScalar y0 = pts[0].fY; - SkScalar x1 = pts[1].fX; - SkScalar y1 = pts[1].fY; - - SkScalar dy = y1 - y0; - - int dir = 1; - if (y0 > y1) { - SkTSwap(y0, y1); - dir = -1; - } - if (y < y0 || y >= y1) { - return 0; - } - - SkScalar cross = SkScalarMul(x1 - x0, y - pts[0].fY) - - SkScalarMul(dy, x - pts[0].fX); - - if (SkScalarSignAsInt(cross) == dir) { - dir = 0; - } - return dir; -} - -bool SkHitTestPathEx(const SkPath& path, SkScalar x, SkScalar y) { - bool isInverse = path.isInverseFillType(); - if (path.isEmpty()) { - return isInverse; - } - - const SkRect& bounds = path.getBounds(); - if (!bounds.contains(x, y)) { - return isInverse; - } - - SkPath::Iter iter(path, true); - bool done = false; - int w = 0; - do { - SkPoint pts[4]; - switch (iter.next(pts, false)) { - case SkPath::kMove_Verb: - case SkPath::kClose_Verb: - break; - case SkPath::kLine_Verb: - w += winding_line(pts, x, y); - break; - case SkPath::kQuad_Verb: - w += winding_quad(pts, x, y); - break; - case SkPath::kCubic_Verb: - w += winding_cubic(pts, x, y); - break; - case SkPath::kDone_Verb: - done = true; - break; - } - } while (!done); - - switch (path.getFillType()) { - case SkPath::kEvenOdd_FillType: - case SkPath::kInverseEvenOdd_FillType: - w &= 1; - break; - } - return SkToBool(w); -} - |