diff options
| -rw-r--r-- | draw_linear_bezier_reference.c | 141 |
1 files changed, 131 insertions, 10 deletions
diff --git a/draw_linear_bezier_reference.c b/draw_linear_bezier_reference.c index a395c18..271e0a8 100644 --- a/draw_linear_bezier_reference.c +++ b/draw_linear_bezier_reference.c @@ -101,6 +101,7 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub #else + #define CHECK_ZEROED()\ do {\ size_t i__;\ @@ -130,7 +131,7 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub static RASTER *raster; -#if 0 +#if 1 static void print_raster(void) { @@ -497,21 +498,134 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift) static double -frand(void) +frand(double a, double b) { int i = rand(); - return (double)i / (double)RAND_MAX; + 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 +try_random_line(double xmin, double xmax, double ymin, double ymax) +{ + double x1 = frand(xmin, xmax); + double y1 = frand(ymin, ymax); + double x2 = frand(xmin, xmax); + double y2 = frand(ymin, ymax); + draw(x1, y1, x2, y2); } static void -try_random_line(void) +check_random_line(double rand_xmin, double rand_xmax, double rand_ymin, double rand_ymax) { - double x1 = frand(); - double y1 = frand(); - double x2 = frand(); - double y2 = frand(); + double x1 = frand(rand_xmin, rand_xmax); + double y1 = frand(rand_ymin, rand_ymax); + double x2 = frand(rand_xmin, rand_xmax); + double y2 = frand(rand_ymin, rand_ymax); + double dx = x2 - x1; + double dy = y2 - y1; + double ymin = fmin(y1, y2); + double ymax = fmax(y1, y2); + double xmin = fmin(x1, x2); + double xmax = fmax(x1, x2); + double ydir = SIGNUM(y2 - y1); + double inklevel, area, expected_area, inkdir, dist; + size_t y, x, jumps; + int hit; + draw(x1, y1, x2, y2); + + area = 0; + for (y = 0; y < 10; y++) { + inklevel = 0; + jumps = 0; + inkdir = 0; + for (x = 0; x < 10; x++) { + area += raster->cells[y * 10 + x].cell_coverage + inklevel; + inklevel += raster->cells[y * 10 + x].opposite_coverage; + + if (inkdir == 0) { + inkdir = raster->cells[y * 10 + x].opposite_coverage; + } else if (inkdir < 0 && raster->cells[y * 10 + x].opposite_coverage > 0) { + ASSERT(!jumps); + jumps += 1; + inkdir = raster->cells[y * 10 + x].opposite_coverage; + } else if (inkdir > 0 && raster->cells[y * 10 + x].opposite_coverage < 0) { + ASSERT(!jumps); + jumps += 1; + inkdir = raster->cells[y * 10 + x].opposite_coverage; + } + + if (!dy) + continue; + + hit = x >= floor(xmin) && x <= ceil(xmax); + hit |= !x && xmin < 0; + hit &= y >= floor(ymin) && y <= ceil(ymax); + ASSERT(hit || !raster->cells[y * 10 + x].cell_coverage); + + hit = x >= floor(xmin) && x <= ceil(xmax); + hit &= y >= floor(ymin) && y <= ceil(ymax); + if (!hit || !dx || !x) + continue; + + dist = ((double)x+0.5)*dy/dx - ((double)y+0.5) + (y1 - x1*dy/dx); + dist /= hypot(dy/dx, 1); + dist = fabs(dist); + if (dist > 0.708) + ASSERT(!raster->cells[y * 10 + x].cell_coverage); + } + + if ((double)y < floor(ymin) || (double)y >= ceil(ymax)) + ASSERT(inklevel == 0.0); + else if ((double)y == floor(ymin)) + ASSERT(eq(inklevel, ydir * (fmin(ymax, (double)y + 1.0) - ymin))); + else if ((double)y == floor(ymax)) + ASSERT(eq(inklevel, ydir * fmod(ymax, 1.0))); + else + ASSERT(eq(inklevel, ydir)); + } + + if (ymax <= 0 || ymin >= 10 || !dy || fmin(x1, x2) >= 10) { + expected_area = 0; + } else if (fmax(x1, x2) < 0) { + expected_area = ydir * 10 * (fmin(10, ymax) - fmax(ymin, 0)); + } else if (!dx) { + expected_area = ydir * (10 - fmin(fmax(0, x1), 10)) * (fmin(10, ymax) - fmax(ymin, 0)); + } else { +#define y(x) (y1 + ((x) - x1) * k) +#define x(y) (x1 + ((y) - y1) / k) + double k = dy / dx; + double a = xmin; + double b = xmax; + double mid; + + a = y(a) > 10 ? x(10) : y(a) < 0 ? x(0) : a; + b = y(b) > 10 ? x(10) : y(b) < 0 ? x(0) : b; + b = fmin(b, 10); + a = fmin(a, 10); + mid = (a + b) / 2; + + if (mid < 0) { + expected_area = (10 - 0) * fabs(y(b) - y(a)); + if (b > 0) + expected_area -= fabs(y(b) - y(0)) * (b - 0) / 2; + } else { + expected_area = (10 - mid) * fabs(y(b) - y(a)); + if (a < 0) + expected_area -= fabs(y(0) - y(a)) * (0 - a) / 2; + } + expected_area *= ydir; +#undef y +#undef x + } + ASSERT(eq(area, expected_area)); + + rtgrpblib_reset_raster(raster, 10, 10); } @@ -547,10 +661,17 @@ main(void) check_11_antidiagonal(-2, 2); check_11_antidiagonal(-2, -2); - for (i = 0; i < 100000UL; i++) - try_random_line(); + for (i = 0; i < 100000UL; i++) { + try_random_line(0., 1., 0., 1.); + try_random_line(-5., 15., -5., 15.); + } rtgrpblib_reset_raster(raster, 10, 10); + for (i = 0; i < 10000UL; i++) { + check_random_line(0., 1., 0., 1.); + check_random_line(-5., 15., -5., 15.); + } + free(raster); return 0; } |