From 743a7dea11ffabf7a6d76dc15a8423b116d1c8c3 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Thu, 9 Feb 2023 13:59:41 +0100 Subject: Test and fix rtgrpblib_draw_quadratic_bezier for perfect lines MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- rtgrpblib_draw_quadratic_bezier.c | 206 +++++++++++++++++++++++++++++++++++--- 1 file changed, 194 insertions(+), 12 deletions(-) (limited to 'rtgrpblib_draw_quadratic_bezier.c') diff --git a/rtgrpblib_draw_quadratic_bezier.c b/rtgrpblib_draw_quadratic_bezier.c index 8aae11e..e2202c6 100644 --- a/rtgrpblib_draw_quadratic_bezier.c +++ b/rtgrpblib_draw_quadratic_bezier.c @@ -90,23 +90,22 @@ rtgrpblib_draw_quadratic_bezier(RASTER *restrict raster, double x1, double y1, size_t nts = 0; size_t i; -#ifdef TODO /* untested */ /* Can we downgrade the curve to a linear Bézier curve? * * (y2 - y1)/(x2 - x1) = (y3 - y2)/(x3 - x2) = (y3 - y1)/(x3 - x1) * (y2 - y1)/(x2 - x1) = (y3 - y2)/(x3 - x2) * (y2 - y1)(x3 - x2) = (y3 - y2)(x2 - x1) */ - if ((y3 - y1) * (x3 - x2) == (y3 - y2) * (x2 - x1)) { - if (x1 <= x2 && x2 <= x3 && y1 <= y2 && y2 <= y3) - rtgrpblib_draw_linear_bezier(raster, x1, y1, x3, y3); - else if (x1 <= x3 && x3 <= x2 && y1 <= y3 && y3 <= y2) - rtgrpblib_draw_linear_bezier(raster, x1, y1, x2, y2); - else - rtgrpblib_draw_linear_bezier(raster, x2, y2, x3, y3); + if ((y2 - y1) * (x3 - x2) == (y3 - y2) * (x2 - x1)) { + /* Drawing (x1, y1)--(x2, y2) plus (x2, y2)--(x3, y3) + * is equivalent to drawing (x1, y1)--(x3, y3) because + * the result is signed and if (x2, y2) is outside the + * (x1, y1)--(x3, y3) line (x2, y2)--(x3, y3) erases + * the part that (x1, y1)--(x2, y2) extends to + * (x1, y1)--(x3, y3) */ + rtgrpblib_draw_linear_bezier(raster, x1, y1, x3, y3); return; } -#endif /* Beginning and end of curve */ ts[nts++] = 0.0; @@ -126,12 +125,12 @@ rtgrpblib_draw_quadratic_bezier(RASTER *restrict raster, double x1, double y1, /* Remove any segments above or below the raster */ y = evaluate_quadratic_bezier(t, y1, y2, y3); - if (y < 0 || y >= (double)raster->height) + if (y < 0 || y > (double)raster->height) continue; /* If the segment is inside the raster, draw it, */ x = evaluate_quadratic_bezier(t, x1, x2, x3); - if (0 <= x && x < (double)raster->width) { + if (0 <= x && x <= (double)raster->width) { draw_bounded_quadratic_bezier(raster, x1, y1, x2, y2, x3, y3, t1, t2); continue; } @@ -157,10 +156,193 @@ rtgrpblib_draw_quadratic_bezier(RASTER *restrict raster, double x1, double y1, #else +static RASTER *raster; +static RASTER *refraster; + + +static double +frand(double a, double b) +{ + int i = rand(); + double f = (double)i / (double)RAND_MAX; + double max = fmax(a, b); + double min = fmin(a, b); + return fma(f, max - min, min); +} + + +static void +check_line(double x1, double y1, double x2, double y2, double x3, double y3, int exact) +{ + size_t i; + + alarm(5); + rtgrpblib_draw_quadratic_bezier(raster, x1, y1, x2, y2, x3, y3); + + alarm(5); + rtgrpblib_draw_linear_bezier(refraster, x1, y1, x3, y3); + + alarm(0); + + if (exact) { + ASSERT(!memcmp(raster->cells, refraster->cells, 100 * sizeof(*raster->cells))); + } else { + for (i = 0; i < 100; i++) { + if (!eq(raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage)) + fprintf(stderr, "c%02zu: %la ref: %la; diff: %lg=%la (tol: %la)\n", i, raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage, refraster->cells[i].cell_coverage - raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage - raster->cells[i].cell_coverage, TOLERANCE); + if (!eq(raster->cells[i].opposite_coverage, refraster->cells[i].opposite_coverage)) + fprintf(stderr, "o%02zu: %la ref: %la; diff: %lg=%la (tol: %la)\n", i, raster->cells[i].opposite_coverage, refraster->cells[i].opposite_coverage, raster->cells[i].opposite_coverage - refraster->cells[i].opposite_coverage, raster->cells[i].opposite_coverage - refraster->cells[i].opposite_coverage, TOLERANCE); + } + for (i = 0; i < 100; i++) { + if (!eq(raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage) || + !eq(raster->cells[i].opposite_coverage, refraster->cells[i].opposite_coverage)) { + print_raster(refraster); + print_raster(raster); + } + ASSERT(eq(raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage)); + ASSERT(eq(raster->cells[i].opposite_coverage, refraster->cells[i].opposite_coverage)); + } + } + rtgrpblib_reset_raster(raster, 10, 10); + rtgrpblib_reset_raster(refraster, 10, 10); +} + + +static void +check_simple_lines(void) +{ + check_line(1, 1, 2, 2, 3, 3, 1); + check_line(1, 1, 3, 3, 2, 2, 1); + check_line(2, 2, 1, 1, 3, 3, 1); + check_line(2, 2, 3, 3, 1, 1, 1); + check_line(3, 3, 1, 1, 2, 2, 1); + check_line(3, 3, 2, 2, 1, 1, 1); + check_line(1, 1, 3, 3, 3, 3, 1); + check_line(1, 1, 1, 1, 3, 3, 1); + + check_line(1, 4, 2, 4, 3, 4, 1); + check_line(1, 4, 3, 4, 2, 4, 1); + check_line(2, 4, 1, 4, 3, 4, 1); + check_line(2, 4, 3, 4, 1, 4, 1); + check_line(3, 4, 1, 4, 2, 4, 1); + check_line(3, 4, 2, 4, 1, 4, 1); + check_line(1, 4, 3, 4, 3, 4, 1); + check_line(1, 4, 1, 4, 3, 4, 1); + + check_line(4, 1, 4, 2, 4, 3, 1); + check_line(4, 1, 4, 3, 4, 2, 1); + check_line(4, 2, 4, 1, 4, 3, 1); + check_line(4, 2, 4, 3, 4, 1, 1); + check_line(4, 3, 4, 1, 4, 2, 1); + check_line(4, 3, 4, 2, 4, 1, 1); + check_line(4, 1, 4, 3, 4, 3, 1); + check_line(4, 1, 4, 1, 4, 3, 1); +} + + +static void +check_random_bounded_lines(int exact) +{ + double x1, x2, x3; + double y1, y2, y3; + double mid; + size_t i; + + for (i = 0; i < 100000UL; i++) { + x1 = floor(frand(0, 11)); + y1 = floor(frand(0, 11)); + x3 = floor(frand(0, 11)); + y3 = floor(frand(0, 11)); + x1 -= (double)(x1 > 10); + x2 -= (double)(x2 > 10); + y1 -= (double)(y1 > 10); + y2 -= (double)(y2 > 10); + mid = frand(0, 1); + + if (x3 - x1) { + x2 = floor(mid * (x3 - x1) + x1); + y2 = y1 + (x2 - x1) * (y3 - y1) / (x3 - x1); + } else if (y3 - y1) { + x2 = x1; + y2 = floor(mid * (y3 - y1) + y1); + } else { + x2 = x1; + y2 = y1; + } + + if (!exact) + check_line(x1, y1, x2, y2, x3, y3, x2 == floor(x2) && y2 == floor(y2)); + else if (x2 == floor(x2) && y2 == floor(y2)) + check_line(x1, y1, x2, y2, x3, y3, 1); + } +} + + +static void +check_random_unbounded_lines(int exact) +{ + double x1, x2, x3; + double y1, y2, y3; + double mid; + size_t i; + + for (i = 0; i < 100000UL; i++) { + x1 = floor(frand(-5, 15)); + y1 = floor(frand(-5, 15)); + x3 = floor(frand(-5, 15)); + y3 = floor(frand(-5, 15)); + mid = frand(-2, 2); + + if (x3 - x1) { + x2 = floor(mid * (x3 - x1) + x1); + y2 = y1 + (x2 - x1) * (y3 - y1) / (x3 - x1); + } else if (y3 - y1) { + x2 = x1; + y2 = floor(mid * (y3 - y1) + y1); + } else { + x2 = x1; + y2 = y1; + } + + if (!exact) + check_line(x1, y1, x2, y2, x3, y3, x2 == floor(x2) && y2 == floor(y2)); + else if (x2 == floor(x2) && y2 == floor(y2)) + check_line(x1, y1, x2, y2, x3, y3, 1); + } +} + + int main(void) { - return 0; /* TODO add test */ + raster = rtgrpblib_create_raster(10, 10); + ASSERT(raster); + refraster = rtgrpblib_create_raster(10, 10); + ASSERT(refraster); + srand((unsigned)(uintptr_t)raster); + + check_simple_lines(); + check_random_bounded_lines(1); + check_random_unbounded_lines(1); + //TODO check_random_bounded_lines(0); + //TODO check_random_unbounded_lines(0); + raster->draftness = -1; + refraster->draftness = -1; + check_simple_lines(); + check_random_bounded_lines(1); + check_random_unbounded_lines(1); +#ifdef TODO_NOT_IMPLEMENTED + check_random_bounded_lines(0); + check_random_unbounded_lines(0); +#endif + raster->draftness = 0.5; + refraster->draftness = 0.5; + + /* TODO add tests */ + + free(raster); + free(refraster); + return 0; } -- cgit v1.2.3-70-g09d2