draw_linear_bezier_reference: fix bounds checking error

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

2 files changed, 49 insertions, 20 deletions

diff --git a/common.h b/common.h
index 67a1c62..805ba0b 100644
--- a/common.h
+++ b/common.h
@@ -123,6 +123,7 @@ PURE_FUNCTION int doublepcmp(const void *avp, const void *bvp);
 
 
 #ifdef TEST
+#include <unistd.h>
 
 #if defined(__GNUC__) && !defined(__clang__)
 # pragma GCC diagnostic ignored "-Wunsuffixed-float-constants"
diff --git a/draw_linear_bezier_reference.c b/draw_linear_bezier_reference.c
index c288781..451eb3a 100644
--- a/draw_linear_bezier_reference.c
+++ b/draw_linear_bezier_reference.c
@@ -56,10 +56,11 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub
 				x = cx;
 
 			/* Make sure loop will exit when we reach the end */
-			if ((xdir < 0 && x < x2) || (xdir > 0 && x > x2))
+			if ((xdir < 0 && x <= x2) || (xdir > 0 && x >= x2) ||
+			    (ydir < 0 && y <= y2) || (ydir > 0 && y >= y2)) {
 				x = x2;
-			if ((ydir < 0 && y < y2) || (ydir > 0 && y > y2))
 				y = y2;
+			}
 		}
 
 		/* Select cell to draw in */
@@ -153,6 +154,17 @@ print_raster(void)
 
 
 static void
+draw(double x1, double y1, double x2, double y2)
+{
+	alarm(5);
+	draw_linear_bezier_reference(raster, x1, y1, x2, y2);
+	alarm(0);
+}
+#undef draw_linear_bezier_reference
+#define draw_linear_bezier_reference "use draw(double, double, double, double) instead"
+
+
+static void
 check_horizontal(void)
 {
 	ssize_t y, x1, x2;
@@ -160,16 +172,16 @@ check_horizontal(void)
 	for (y = -2; y < 12; y++) {
 		for (x1 = -2; x1 < 12; x1++) {
 			for (x2 = -2; x2 < 12; x2++) {
-				draw_linear_bezier_reference(raster, x1, y, x2, y);
+				draw(x1, y, x2, y);
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x1 + 0.25, y, x2 + 0.25, y);
+				draw(x1 + 0.25, y, x2 + 0.25, y);
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x1, y + 0.25, x2, y + 0.25);
+				draw(x1, y + 0.25, x2, y + 0.25);
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x1 + 0.25, y + 0.25, x2 + 0.25, y + 0.25);
+				draw(x1 + 0.25, y + 0.25, x2 + 0.25, y + 0.25);
 				CHECK_ZEROED();
 			}
 		}
@@ -188,7 +200,7 @@ check_vertical(void)
 			for (y2 = -2; y2 < 12; y2++) {
 				ydir = SIGNUM(y2 - y1);
 
-				draw_linear_bezier_reference(raster, x, y1, x, y2);
+				draw(x, y1, x, y2);
 				for (i = 0; i < 10; i++) {
 					if (i < y1 && i < y2)
 						continue;
@@ -201,7 +213,7 @@ check_vertical(void)
 				}
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x + 0.25, y1, x + 0.25, y2);
+				draw(x + 0.25, y1, x + 0.25, y2);
 				for (i = 0; i < 10; i++) {
 					if (i < y1 && i < y2)
 						continue;
@@ -214,7 +226,7 @@ check_vertical(void)
 				}
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x, y1 + 0.25, x, y2 + 0.25);
+				draw(x, y1 + 0.25, x, y2 + 0.25);
 				for (i = 0; i < 10; i++) {
 					if (i < y1 + (y1 > y2) && i < y2 + (y2 > y1))
 						continue;
@@ -228,7 +240,7 @@ check_vertical(void)
 				}
 				CHECK_ZEROED();
 
-				draw_linear_bezier_reference(raster, x + 0.25, y1 + 0.25, x + 0.25, y2 + 0.25);
+				draw(x + 0.25, y1 + 0.25, x + 0.25, y2 + 0.25);
 				for (i = 0; i < 10; i++) {
 					if (i < y1 + (y1 > y2) && i < y2 + (y2 > y1))
 						continue;
@@ -258,7 +270,7 @@ check_11_diagonal(ssize_t xshift, ssize_t yshift)
 			imax = i1 > i2 ? i1 : i2;
 			idir = SIGNUM(i2 - i1);
 
-			draw_linear_bezier_reference(raster, i1 + xshift, i1 + yshift, i2 + xshift, i2 + yshift);
+			draw(i1 + xshift, i1 + yshift, i2 + xshift, i2 + yshift);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = i + yshift;
@@ -273,7 +285,7 @@ check_11_diagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift, i1 + yshift + 0.25, i2 + xshift, i2 + yshift + 0.25);
+			draw(i1 + xshift, i1 + yshift + 0.25, i2 + xshift, i2 + yshift + 0.25);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = i + yshift;
@@ -298,7 +310,7 @@ check_11_diagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift + 0.25, i1 + yshift, i2 + xshift + 0.25, i2 + yshift);
+			draw(i1 + xshift + 0.25, i1 + yshift, i2 + xshift + 0.25, i2 + yshift);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = i + yshift;
@@ -323,8 +335,7 @@ check_11_diagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift + 0.25, i1 + yshift + 0.25,
-			                                     i2 + xshift + 0.25, i2 + yshift + 0.25);
+			draw(i1 + xshift + 0.25, i1 + yshift + 0.25, i2 + xshift + 0.25, i2 + yshift + 0.25);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = i + yshift;
@@ -364,7 +375,7 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
 			imax = i1 > i2 ? i1 : i2;
 			ydir = -SIGNUM(i2 - i1);
 
-			draw_linear_bezier_reference(raster, i1 + xshift, i2 + yshift, i2 + xshift, i1 + yshift);
+			draw(i1 + xshift, i2 + yshift, i2 + xshift, i1 + yshift);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = imax - i + imin + yshift - 1;
@@ -379,7 +390,7 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift, i2 + yshift + 0.25, i2 + xshift, i1 + yshift + 0.25);
+			draw(i1 + xshift, i2 + yshift + 0.25, i2 + xshift, i1 + yshift + 0.25);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = imax - i + imin + yshift - 1;
@@ -404,7 +415,7 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift + 0.25, i2 + yshift, i2 + xshift + 0.25, i1 + yshift);
+			draw(i1 + xshift + 0.25, i2 + yshift, i2 + xshift + 0.25, i1 + yshift);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = imax - i + imin + yshift - 1;
@@ -429,8 +440,7 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
 			}
 			CHECK_ZEROED();
 
-			draw_linear_bezier_reference(raster, i1 + xshift + 0.25, i2 + yshift + 0.25,
-			                                     i2 + xshift + 0.25, i1 + yshift + 0.25);
+			draw(i1 + xshift + 0.25, i2 + yshift + 0.25, i2 + xshift + 0.25, i1 + yshift + 0.25);
 			for (i = imin; i < imax; i++) {
 				x = i + xshift;
 				y = imax - i + imin + yshift - 1;
@@ -469,11 +479,25 @@ check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
 }
 
 
+static void
+try_random_line(void)
+{
+	double x1 = (double)rand() / (double)RAND_MAX;
+	double y1 = (double)rand() / (double)RAND_MAX;
+	double x2 = (double)rand() / (double)RAND_MAX;
+	double y2 = (double)rand() / (double)RAND_MAX;
+	draw(x1, y1, x2, y2);
+}
+
+
 int
 main(void)
 {
+	size_t i;
+
 	raster = rtgrpblib_create_raster(10, 10);
 	ASSERT(raster);
+	srand((unsigned)(uintptr_t)raster);
 
 	check_horizontal();
 	check_vertical();
@@ -498,6 +522,10 @@ main(void)
 	check_11_antidiagonal(-2, 2);
 	check_11_antidiagonal(-2, -2);
 
+	for (i = 0; i < 100000UL; i++)
+		try_random_line();
+	rtgrpblib_reset_raster(raster, 10, 10);
+
 	free(raster);
 	return 0;
 }