Test rtgrpblib_draw_linear_bezier

Signed-off-by: Mattias Andrée <maandree@kth.se>

2 files changed, 119 insertions, 20 deletions

diff --git a/common.h b/common.h
index 2e8b8bc..80f807c 100644
--- a/common.h
+++ b/common.h
@@ -159,4 +159,25 @@ intolerant_eq(double a, double b)
 		}\
 	} while (0)
 
+# if 0
+static void
+print_raster(const RASTER *r) {
+	size_t y, x;
+	fprintf(stderr, "\nOutline (area)\n");
+	for (y = 0; y < r->height; y++) {
+		for (x = 0; x < r->width; x++)
+			fprintf(stderr, r->cells[y * r->width + x].cell_coverage ? "%+.4lf " : " 0      ",
+			                r->cells[y * r->width + x].cell_coverage);
+		printf("\n");
+	}
+	fprintf(stderr, "\nOutline (shadow)\n");
+	for (y = 0; y < r->height; y++) {
+		for (x = 0; x < r->width; x++)
+			fprintf(stderr, r->cells[y * r->width + x].opposite_coverage ? "%+.4lf " : " 0      ",
+			                r->cells[y * r->width + x].opposite_coverage);
+		printf("\n");
+	}
+}
+# endif
+
 #endif
diff --git a/rtgrpblib_draw_linear_bezier.c b/rtgrpblib_draw_linear_bezier.c
index ba8dc48..8cefcb1 100644
--- a/rtgrpblib_draw_linear_bezier.c
+++ b/rtgrpblib_draw_linear_bezier.c
@@ -7,19 +7,21 @@ void
 rtgrpblib_draw_linear_bezier(RASTER *restrict raster, double x1, double y1, double x2, double y2)
 {
 	double w, h, dx, dy, x, y;
-	int xdir, ydir;
 
 	if (raster->draftness <= 0) {
 		draw_linear_bezier_reference(raster, x1, y1, x2, y2);
 		return;
 	}
 
-	dx = x2 - x1;
-	dy = y2 - y1;
-	xdir = SIGNUM(dx);
-	ydir = SIGNUM(dy);
+#define CALC_SLOPE()\
+	do {\
+		dx = x2 - x1;\
+		dy = y2 - y1;\
+	} while (0)
 
-	if (!ydir) {
+	CALC_SLOPE();
+
+	if (!dy) {
 		/* For horizontal lines, it is enough that we have the
 		 * corners mapped onto the raster, which we must have
 		 * since a glyph cannot just contain a line, but outlines:
@@ -32,23 +34,27 @@ rtgrpblib_draw_linear_bezier(RASTER *restrict raster, double x1, double y1, doub
 	/* We cut of everything above and below the raster,
 	 * as these do not contribute to the result */
 	h = (double)raster->height;
-	if (y1 < 0 && y2 < 0)
+	if (y1 <= 0 && y2 <= 0)
 		return;
 	if (y1 >= h && y2 >= h)
 		return;
 	if (y1 < 0 && y2 >= 0) {
 		x1 = x1 + (0 - y1) * dx / dy;
 		y1 = 0;
+		CALC_SLOPE();
 	} else if (y2 < 0 && y1 >= 0) {
 		x2 = x1 + (0 - y1) * dx / dy;
 		y2 = 0;
+		CALC_SLOPE();
 	}
-	if (y1 < h && y2 >= h) {
+	if (y1 <= h && y2 > h) {
 		x2 = x1 + (h - y1) * dx / dy;
 		y2 = h;
-	} else if (y2 < h && y1 >= h) {
+		CALC_SLOPE();
+	} else if (y2 <= h && y1 > h) {
 		x1 = x1 + (h - y1) * dx / dy;
 		y1 = h;
+		CALC_SLOPE();
 	}
 
 	/* Dealing with the left and the right section
@@ -61,60 +67,132 @@ rtgrpblib_draw_linear_bezier(RASTER *restrict raster, double x1, double y1, doub
 	 * edge, or rather their show on the edges are
 	 * used. */
 	w = (double)raster->width;
-	if (x1 <= 0 && x2 <= 0) {
-		draw_vertical_line(raster, 0, y1, y2, ydir);
+	if (x1 < 0 && x2 < 0) {
+		draw_vertical_line(raster, 0, y1, y2, SIGNUM(dy));
 		return;
 	}
 	if (x1 >= w && x2 >= w) {
-		draw_vertical_line_opposite_only(raster, raster->width - 1, y1, y2, ydir);
+		draw_vertical_line_opposite_only(raster, raster->width - 1, y1, y2, SIGNUM(dy));
 		return;
 	}
 	if (x1 < 0 && x2 >= 0) {
 		y = y1 + (0 - x1) * dy / dx;
 		x = 0;
-		draw_vertical_line(raster, 0, y1, y, ydir);
+		draw_vertical_line(raster, 0, y1, y, SIGNUM(y - y1));
 		x1 = x;
 		y1 = y;
+		CALC_SLOPE();
 	} else if (x2 < 0 && x1 >= 0) {
 		y = y1 + (0 - x1) * dy / dx;
 		x = 0;
-		draw_vertical_line(raster, 0, y, y2, ydir);
+		draw_vertical_line(raster, 0, y, y2, SIGNUM(y2 - y));
 		x2 = x;
 		y2 = y;
+		CALC_SLOPE();
 	}
 	if (x1 < w && x2 >= w) {
 		y = y1 + (w - x1) * dy / dx;
 		x = w;
-		draw_vertical_line_opposite_only(raster, raster->width - 1, y, y2, ydir);
+		draw_vertical_line_opposite_only(raster, raster->width - 1, y, y2, SIGNUM(y2 - y));
 		x2 = x;
 		y2 = y;
+		CALC_SLOPE();
 	} else if (x2 < w && x1 >= w) {
 		y = y1 + (w - x1) * dy / dx;
 		x = w;
-		draw_vertical_line_opposite_only(raster, raster->width - 1, y1, y, ydir);
+		draw_vertical_line_opposite_only(raster, raster->width - 1, y1, y, SIGNUM(y - y1));
 		x1 = x;
 		y1 = y;
+		CALC_SLOPE();
 	}
 
 	/* Now we can finally draw the part of the
 	 * line that is inside the raster */
-	if (!xdir) {
+	if (!dx) {
 		/* Optimisation for vertical lines. It also serves
 		 * to illustrate how the algorithm is designed. */
-		draw_vertical_line(raster, x1, y1, y2, ydir);
+		draw_vertical_line(raster, x1, y1, y2, SIGNUM(dy));
 	} else {
-		draw_diagonal_line(raster, x1, y1, x2, y2, dx, dy, xdir, ydir);
+		draw_diagonal_line(raster, x1, y1, x2, y2, dx, dy, SIGNUM(dx), SIGNUM(dy));
 	}
+
+#undef CALC_SLOPE
 }
 
 
 #else
 
 
+static RASTER *raster;
+static RASTER *refraster;
+
+
+static void
+check_draw_linear_bezier(double x1, double y1, double x2, double y2)
+{
+	size_t i;
+	alarm(5);
+	rtgrpblib_draw_linear_bezier(raster, x1, y1, x2, y2);
+	alarm(5);
+	draw_linear_bezier_reference(refraster, x1, y1, x2, y2);
+	alarm(0);
+	for (i = 0; i < 100; i++) {
+		ASSERT(intolerant_eq(raster->cells[i].cell_coverage, refraster->cells[i].cell_coverage));
+		ASSERT(intolerant_eq(raster->cells[i].opposite_coverage, refraster->cells[i].opposite_coverage));
+	}
+	rtgrpblib_reset_raster(raster, 10, 10);
+	rtgrpblib_reset_raster(refraster, 10, 10);
+}
+
+
+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);
+}
+
+
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	double x1, x2;
+	double y1, y2;
+	size_t i;
+
+	raster = rtgrpblib_create_raster(10, 10);
+	ASSERT(raster);
+	refraster = rtgrpblib_create_raster(10, 10);
+	ASSERT(refraster);
+	srand((unsigned)(uintptr_t)raster);
+
+	for (i = 0; i < 10000UL; i++) {
+#ifndef ROWWISE_RESET_INKLEVEL
+		x1 = frand(-5, 15);
+		y1 = frand(-5, 15);
+		x2 = frand(-5, 15);
+		y2 = frand(-5, 15);
+#else
+		x1 = frand(0, 10);
+		y1 = frand(-5, 15);
+		x2 = frand(-5, 10);
+		y2 = frand(-5, 15);
+#endif
+
+		check_draw_linear_bezier(x1, y1, x2, y2);
+		check_draw_linear_bezier(x1, x1, x2, x2);
+		check_draw_linear_bezier(x1, x2, x2, x1);
+		check_draw_linear_bezier(x1, y1, x2, y1);
+		check_draw_linear_bezier(x1, y1, x1, y2);
+		/* TODO test with zero draftness */
+	}
+
+	free(raster);
+	free(refraster);
+	return 0;
 }