CubicMapTest.cpp File Reference

#include "include/core/SkCubicMap.h"
#include "include/core/SkPoint.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkDebug.h"
#include "src/base/SkCubics.h"
#include "src/base/SkVx.h"
#include "src/core/SkGeometry.h"
#include "tests/Test.h"

Go to the source code of this file.

Functions
static float	accurate_t (float A, float B, float C, float D)
static float	accurate_solve (SkPoint p1, SkPoint p2, SkScalar x)
static bool	nearly_le (SkScalar a, SkScalar b)
static void	exercise_cubicmap (SkPoint p1, SkPoint p2, skiatest::Reporter *reporter)
	DEF_TEST (CubicMap, r)

Function Documentation

accurate_solve()

static float accurate_solve ( SkPoint  p1, SkPoint  p2, SkScalar  x  )

static

Definition at line 25 of file CubicMapTest.cpp.

                                                                {
    SkPoint array[] = { {0, 0}, p1, p2, {1,1} };
    SkCubicCoeff coeff(array);
 
    float t = accurate_t(coeff.fA[0], coeff.fB[0], coeff.fC[0], coeff.fD[0] - x);
    SkASSERT(t >= 0 && t <= 1);
    float y = coeff.eval(t)[1];
    SkASSERT(y >= 0 && y <= 1.0001f);
    return y;
}

accurate_t()

static float accurate_t ( float  A, float  B, float  C, float  D  )

static

Definition at line 18 of file CubicMapTest.cpp.

                                                            {
    double roots[3];
    SkDEBUGCODE(int count =) SkCubics::RootsValidT(A, B, C, D, roots);
    SkASSERT(count == 1);
    return (float)roots[0];
}

DEF_TEST()

DEF_TEST	(	CubicMap	,
		r
	)

Definition at line 63 of file CubicMapTest.cpp.

                      {
    const SkScalar values[] = {
        0, 1, 0.5f, 0.0000001f, 0.999999f,
    };
 
    for (SkScalar x0 : values) {
        for (SkScalar y0 : values) {
            for (SkScalar x1 : values) {
                for (SkScalar y1 : values) {
                    exercise_cubicmap({ x0, y0 }, { x1, y1 }, r);
                }
            }
        }
    }
}

exercise_cubicmap()

static void exercise_cubicmap ( SkPoint  p1, SkPoint  p2, skiatest::Reporter *  reporter  )

static

Definition at line 40 of file CubicMapTest.cpp.

                                                                                  {
    const SkScalar MAX_SOLVER_ERR = 0.008f; // found by running w/ current impl
 
    SkCubicMap cmap(p1, p2);
 
    SkScalar prev_y = 0;
    SkScalar dx = 1.0f / 512;
    for (SkScalar x = dx; x < 1; x += dx) {
        SkScalar y = cmap.computeYFromX(x);
        // are we valid and (mostly) monotonic?
        if (!nearly_le(prev_y, y)) {
            cmap.computeYFromX(x);
            REPORTER_ASSERT(reporter, false);
        }
        prev_y = y;
 
        // are we close to the "correct" answer?
        SkScalar yy = accurate_solve(p1, p2, x);
        SkScalar diff = SkScalarAbs(yy - y);
        REPORTER_ASSERT(reporter, diff < MAX_SOLVER_ERR);
    }
}

nearly_le()

static bool nearly_le ( SkScalar  a, SkScalar  b  )

static

Definition at line 36 of file CubicMapTest.cpp.

                                              {
    return a <= b || SkScalarNearlyZero(a - b);
}