skia2/experimental/Intersection/CubicParameterization_TestUtility.cpp
caryclark@google.com f47c217cc8 overzealously deleted files
git-svn-id: http://skia.googlecode.com/svn/trunk@3502 2bbb7eff-a529-9590-31e7-b0007b416f81
2012-03-27 13:45:24 +00:00

54 lines
1.9 KiB
C++

// included by CubicParameterization.cpp
// accesses internal functions to validate parameterized coefficients
#include "Parameterization_Test.h"
static void parameter_coeffs(const Cubic& cubic, double coeffs[coeff_count]) {
#if USE_SYVESTER
double ax, bx, cx, dx;
if (try_alt)
alt_set_abcd(&cubic[0].x, ax, bx, cx, dx);
else
set_abcd(&cubic[0].x, ax, bx, cx, dx);
double ay, by, cy, dy;
if (try_alt)
alt_set_abcd(&cubic[0].y, ay, by, cy, dy);
else
set_abcd(&cubic[0].y, ay, by, cy, dy);
calc_ABCD(ax, ay, coeffs);
if (!try_alt) calc_bc(dx, bx, cx);
if (!try_alt) calc_bc(dy, by, cy);
#else
double ax = cubic[0].x;
double bx = cubic[1].x;
double cx = cubic[2].x;
double dx = cubic[3].x;
double ay = cubic[0].y;
double by = cubic[1].y;
double cy = cubic[2].y;
double dy = cubic[3].y;
calc_ABCD(ax, bx, cx, dx, ay, by, cy, dy, coeffs);
#endif
for (int index = xx_coeff; index < coeff_count; ++index) {
int procIndex = index - xx_coeff;
coeffs[index] = (*calc_proc[procIndex])(ax, bx, cx, dx, ay, by, cy, dy);
}
}
bool point_on_parameterized_curve(const Cubic& cubic, const _Point& point) {
double coeffs[coeff_count];
parameter_coeffs(cubic, coeffs);
double xxx = coeffs[xxx_coeff] * point.x * point.x * point.x;
double xxy = coeffs[xxy_coeff] * point.x * point.x * point.y;
double xyy = coeffs[xyy_coeff] * point.x * point.y * point.y;
double yyy = coeffs[yyy_coeff] * point.y * point.y * point.y;
double xx = coeffs[ xx_coeff] * point.x * point.x;
double xy = coeffs[ xy_coeff] * point.x * point.y;
double yy = coeffs[ yy_coeff] * point.y * point.y;
double x = coeffs[ x_coeff] * point.x;
double y = coeffs[ y_coeff] * point.y;
double c = coeffs[ c_coeff];
double sum = xxx + xxy + xyy + yyy + xx + xy + yy + x + y + c;
return approximately_zero(sum);
}