Fix two trivial errors in draw_linear_bezier_reference and add some tests

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

1 files changed, 398 insertions, 3 deletions

diff --git a/draw_linear_bezier_reference.c b/draw_linear_bezier_reference.c
index 6066946..c288781 100644
--- a/draw_linear_bezier_reference.c
+++ b/draw_linear_bezier_reference.c
@@ -31,7 +31,7 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub
 	prevX = x1;
 	prevY = y1;
 
-	for (; prevX != x2 && prevY != y2; prevX = x, prevY = y) {
+	for (; prevX != x2 || prevY != y2; prevX = x, prevY = y) {
 		/* Find next vertical and next hozitonal grid line */
 		x = xdir < 0 ? floor(prevX) : xdir > 0 ? ceil(prevX) : prevX;
 		y = ydir < 0 ? floor(prevY) : ydir > 0 ? ceil(prevY) : prevY;
@@ -92,7 +92,7 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub
 			/* If inside the raster, just draw the line */
 			cell = (size_t)cellY * raster->width + (size_t)cellX;
 			raster->cells[cell].opposite_coverage += y - prevY;
-			raster->cells[cell].cell_coverage += (y - prevY) * fabs(fmax(ceil(x), ceil(prevX)) - (x + prevX) / 2.0);
+			raster->cells[cell].cell_coverage += (y - prevY) * fabs(xfloor + 1.0 - (x + prevX) / 2.0);
 		}
 	}
 }
@@ -100,11 +100,406 @@ draw_linear_bezier_reference(RASTER *restrict raster, double x1, double y1, doub
 
 #else
 
+#define CHECK_ZEROED()\
+	do {\
+		size_t i__;\
+		for (i__ = 0; i__ < 100; i__++) {\
+			ASSERT(!raster->cells[i__].cell_coverage);\
+			ASSERT(!raster->cells[i__].opposite_coverage);\
+		}\
+	} while (0)
+
+#define CHECK_CELL(X, Y, AREA, SHADOW)\
+	do {\
+		size_t i__ = (Y) * raster->width + (X);\
+		ASSERT(raster->cells[i__].cell_coverage == (AREA));\
+		ASSERT(raster->cells[i__].opposite_coverage == (SHADOW));\
+		raster->cells[i__].cell_coverage = 0;\
+		raster->cells[i__].opposite_coverage = 0;\
+	} while (0)
+
+#define SUB_CELL(X, Y, AREA, SHADOW)\
+	do {\
+		size_t i__ = (Y) * raster->width + (X);\
+		raster->cells[i__].cell_coverage -= (AREA);\
+		raster->cells[i__].opposite_coverage -= (SHADOW);\
+	} while (0)
+
+
+static RASTER *raster;
+
+
+#if 0
+static void
+print_raster(void)
+{
+	size_t y, x;
+	printf("\nOutline (area)\n");
+	for (y = 0; y < raster->height; y++) {
+		for (x = 0; x < raster->width; x++)
+			printf(raster->cells[y * raster->width + x].cell_coverage ? "%+.4lf " : " 0      ",
+			       raster->cells[y * raster->width + x].cell_coverage);
+		printf("\n");
+	}
+	printf("\nOutline (shadow)\n");
+	for (y = 0; y < raster->height; y++) {
+		for (x = 0; x < raster->width; x++)
+			printf(raster->cells[y * raster->width + x].opposite_coverage ? "%+.4lf " : " 0      ",
+			       raster->cells[y * raster->width + x].opposite_coverage);
+		printf("\n");
+	}
+}
+#endif
+
+
+static void
+check_horizontal(void)
+{
+	ssize_t y, x1, x2;
+
+	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);
+				CHECK_ZEROED();
+
+				draw_linear_bezier_reference(raster, x1 + 0.25, y, x2 + 0.25, y);
+				CHECK_ZEROED();
+
+				draw_linear_bezier_reference(raster, 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);
+				CHECK_ZEROED();
+			}
+		}
+	}
+}
+
+
+static void
+check_vertical(void)
+{
+	ssize_t x, y1, y2, i, ydir;
+	double yhit;
+
+	for (x = -2; x < 12; x++) {
+		for (y1 = -2; y1 < 12; y1++) {
+			for (y2 = -2; y2 < 12; y2++) {
+				ydir = SIGNUM(y2 - y1);
+
+				draw_linear_bezier_reference(raster, x, y1, x, y2);
+				for (i = 0; i < 10; i++) {
+					if (i < y1 && i < y2)
+						continue;
+					if (i >= y1 && i >= y2)
+						continue;
+					CHECK_CELL(x < 0 ? 0 : x < 10 ? x : 9,
+					           i,
+						   x < 0 ? (double)ydir : x < 10 ? (double)ydir : 0,
+					           (double)ydir);
+				}
+				CHECK_ZEROED();
+
+				draw_linear_bezier_reference(raster, x + 0.25, y1, x + 0.25, y2);
+				for (i = 0; i < 10; i++) {
+					if (i < y1 && i < y2)
+						continue;
+					if (i >= y1 && i >= y2)
+						continue;
+					CHECK_CELL(x < 0 ? 0 : x < 10 ? x : 9,
+					           i,
+						   x < 0 ? (double)ydir : x < 10 ? (double)ydir * 0.75 : 0,
+					           (double)ydir);
+				}
+				CHECK_ZEROED();
+
+				draw_linear_bezier_reference(raster, x, y1 + 0.25, x, y2 + 0.25);
+				for (i = 0; i < 10; i++) {
+					if (i < y1 + (y1 > y2) && i < y2 + (y2 > y1))
+						continue;
+					if (i >= y1 + (y1 > y2) && i >= y2 + (y2 > y1))
+						continue;
+					yhit = i == (y1 < y2 ? y1 : y2) ? 0.75 : i == (y2 > y1 ? y2 : y1) ? 0.25 : 1.0;
+					CHECK_CELL(x < 0 ? 0 : x < 10 ? x : 9,
+					           i,
+						   (x < 0 ? (double)ydir : x < 10 ? (double)ydir : 0) * yhit,
+					           (double)ydir * yhit);
+				}
+				CHECK_ZEROED();
+
+				draw_linear_bezier_reference(raster, 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;
+					if (i >= y1 + (y1 > y2) && i >= y2 + (y2 > y1))
+						continue;
+					yhit = i == (y1 < y2 ? y1 : y2) ? 0.75 : i == (y2 > y1 ? y2 : y1) ? 0.25 : 1.0;
+					CHECK_CELL(x < 0 ? 0 : x < 10 ? x : 9,
+					           i,
+						   (x < 0 ? (double)ydir : x < 10 ? (double)ydir * 0.75 : 0) * yhit,
+					           (double)ydir * yhit);
+				}
+				CHECK_ZEROED();
+			}
+		}
+	}
+}
+
+
+static void
+check_11_diagonal(ssize_t xshift, ssize_t yshift)
+{
+	ssize_t i1, i2, i, imin, imax, idir, x, y;
+
+	for (i1 = -2; i1 < 12; i1++) {
+		for (i2 = -2; i2 < 12; i2++) {
+			imin = i1 < i2 ? i1 : i2;
+			imax = i1 > i2 ? i1 : i2;
+			idir = SIGNUM(i2 - i1);
+
+			draw_linear_bezier_reference(raster, i1 + xshift, i1 + yshift, i2 + xshift, i2 + yshift);
+			for (i = imin; i < imax; i++) {
+				x = i + xshift;
+				y = i + yshift;
+				if (y < 0 || y >= 10)
+					continue;
+				if (x >= 10)
+					CHECK_CELL(9, y, 0, idir);
+				else if (x >= 0)
+					CHECK_CELL(x, y, 0.5 * idir, idir);
+				else
+					CHECK_CELL(0, y, idir, idir);
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, i1 + xshift, i1 + yshift + 0.25, i2 + xshift, i2 + yshift + 0.25);
+			for (i = imin; i < imax; i++) {
+				x = i + xshift;
+				y = i + yshift;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.75);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * (0.75 - 0.75 * 0.75 / 2), idir * 0.75);
+					else
+						SUB_CELL(0, y, idir * 0.75, idir * 0.75);
+				}
+				x = i + xshift;
+				y = i + yshift + 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * 0.25 * 0.25 / 2, idir * 0.25);
+					else
+						SUB_CELL(0, y, idir * 0.25, idir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, i1 + xshift + 0.25, i1 + yshift, i2 + xshift + 0.25, i2 + yshift);
+			for (i = imin; i < imax; i++) {
+				x = i + xshift;
+				y = i + yshift;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.75);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * 0.75 * 0.75 / 2, idir * 0.75);
+					else
+						SUB_CELL(0, y, idir * 0.75, idir * 0.75);
+				}
+				x = i + xshift + 1;
+				y = i + yshift;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * (0.25 - 0.25 * 0.25 / 2), idir * 0.25);
+					else
+						SUB_CELL(0, y, idir * 0.25, idir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, 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;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.75);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * 0.75 * 0.75 / 2, idir * 0.75);
+					else
+						SUB_CELL(0, y, idir * 0.75, idir * 0.75);
+				}
+				x = i + xshift + 1;
+				y = i + yshift + 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, idir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, idir * (0.25 - 0.25 * 0.25 / 2), idir * 0.25);
+					else
+						SUB_CELL(0, y, idir * 0.25, idir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+		}
+	}
+}
+
+
+static void
+check_11_antidiagonal(ssize_t xshift, ssize_t yshift)
+{
+	ssize_t i1, i2, i, imin, imax, ydir, x, y;
+
+	for (i1 = -2; i1 < 12; i1++) {
+		for (i2 = -2; i2 < 12; i2++) {
+			imin = i1 < i2 ? i1 : i2;
+			imax = i1 > i2 ? i1 : i2;
+			ydir = -SIGNUM(i2 - i1);
+
+			draw_linear_bezier_reference(raster, i1 + xshift, i2 + yshift, i2 + xshift, i1 + yshift);
+			for (i = imin; i < imax; i++) {
+				x = i + xshift;
+				y = imax - i + imin + yshift - 1;
+				if (y < 0 || y >= 10)
+					continue;
+				if (x >= 10)
+					CHECK_CELL(9, y, 0, ydir);
+				else if (x >= 0)
+					CHECK_CELL(x, y, 0.5 * ydir, ydir);
+				else
+					CHECK_CELL(0, y, ydir, ydir);
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, 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;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.75);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * 0.75 * 0.75 / 2, ydir * 0.75);
+					else
+						SUB_CELL(0, y, ydir * 0.75, ydir * 0.75);
+				}
+				x = i + xshift;
+				y = imax - i + imin + yshift - 1 + 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * (0.25 - 0.25 * 0.25 / 2), ydir * 0.25);
+					else
+						SUB_CELL(0, y, ydir * 0.25, ydir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, 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;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.75);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * 0.75 * 0.75 / 2, ydir * 0.75);
+					else
+						SUB_CELL(0, y, ydir * 0.75, ydir * 0.75);
+				}
+				x = i + xshift + 1;
+				y = imax - i + imin + yshift - 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * (0.25 - 0.25 * 0.25 / 2), ydir * 0.25);
+					else
+						SUB_CELL(0, y, ydir * 0.25, ydir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+
+			draw_linear_bezier_reference(raster, 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;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.5);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir / 8.0, ydir * 0.5);
+					else
+						SUB_CELL(0, y, ydir * 0.5, ydir * 0.5);
+				}
+				x = i + xshift;
+				y = imax - i + imin + yshift - 1 + 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * (2.5 / 16.0), ydir * 0.25);
+					else
+						SUB_CELL(0, y, ydir * 0.25, ydir * 0.25);
+				}
+				x = i + xshift + 1;
+				y = imax - i + imin + yshift - 1;
+				if (0 <= y && y < 10) {
+					if (x >= 10)
+						SUB_CELL(9, y, 0, ydir * 0.25);
+					else if (x >= 0)
+						SUB_CELL(x, y, ydir * (3.5 / 16.0), ydir * 0.25);
+					else
+						SUB_CELL(0, y, ydir * 0.25, ydir * 0.25);
+				}
+			}
+			CHECK_ZEROED();
+		}
+	}
+}
+
 
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	raster = rtgrpblib_create_raster(10, 10);
+	ASSERT(raster);
+
+	check_horizontal();
+	check_vertical();
+
+	check_11_diagonal(0, 0);
+	check_11_diagonal(0, 2);
+	check_11_diagonal(0, -2);
+	check_11_diagonal(2, 0);
+	check_11_diagonal(2, 2);
+	check_11_diagonal(2, -2);
+	check_11_diagonal(-2, 0);
+	check_11_diagonal(-2, 2);
+	check_11_diagonal(-2, -2);
+
+	check_11_antidiagonal(0, 0);
+	check_11_antidiagonal(0, 2);
+	check_11_antidiagonal(0, -2);
+	check_11_antidiagonal(2, 0);
+	check_11_antidiagonal(2, 2);
+	check_11_antidiagonal(2, -2);
+	check_11_antidiagonal(-2, 0);
+	check_11_antidiagonal(-2, 2);
+	check_11_antidiagonal(-2, -2);
+
+	free(raster);
+	return 0;
 }