Add tests and documentation

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

7 files changed, 271 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index 370c2fe..300fb5f 100644
--- a/Makefile
+++ b/Makefile
@@ -16,19 +16,20 @@ LIB_VERSION = $(LIB_MAJOR).$(LIB_MINOR)
 LIB_NAME = rifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket
 
 
+# OBJ is sorted in testing order
 OBJ =\
 	equations.o\
-	lines.o\
 	sorting.o\
-	draw_linear_bezier_reference.o\
 	rtgrpblib_create_raster.o\
+	rtgrpblib_reset_raster.o\
+	rtgrpblib_set_draftness.o\
+	draw_linear_bezier_reference.o\
+	lines.o\
 	rtgrpblib_draw_circular_arc.o\
 	rtgrpblib_draw_linear_bezier.o\
 	rtgrpblib_draw_quadratic_bezier.o\
 	rtgrpblib_draw_cubic_bezier.o\
-	rtgrpblib_fill_shapes.o\
-	rtgrpblib_reset_raster.o\
-	rtgrpblib_set_draftness.o
+	rtgrpblib_fill_shapes.o
 
 HDR =\
 	lib$(LIB_NAME).h\
diff --git a/common.h b/common.h
index 2436a6a..67a1c62 100644
--- a/common.h
+++ b/common.h
@@ -29,6 +29,8 @@
 
 #define SIGNUM(X) (((X) > 0) - ((X) < 0))
 
+#define DEFAULT_DRAFTNESS 0.5
+
 #define draw_vertical_line_opposite_only(...)
 
 
@@ -66,6 +68,7 @@ typedef struct rtgrpblib_cell {
 typedef struct rtgrpblib_raster {
 	size_t height;
 	size_t width;
+	size_t size;
 	double draftness; /* TODO support 0 */
 	CELL cells[];
 } RASTER;
diff --git a/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h b/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h
index fffeae7..97d57c3 100644
--- a/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h
+++ b/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h
@@ -5,36 +5,133 @@
 #include <stddef.h>
 
 
+/**
+ * Object that the library draws on, is converted to
+ * an ink-level image using the `rtgrpblib_fill_shapes`
+ * function. This object also contain drawing
+ * configurations.
+ */
 typedef struct rtgrpblib_raster RTGRPBLIB_RASTER;
 
 
+/**
+ * Create a buffer that the library can use for drawing
+ *
+ * @param   width   The width of the buffer
+ * @param   height  The height of the buffer
+ * @return          Drawing buffer, which can be deallocated with (3),
+ *                  or `NULL` on failure
+ * 
+ * @throws  EINVAL  `width` or `height` is zero
+ * @throws  ENOMEM  Cannot allocate enough memory
+ * 
+ * @seealso  rtgrpblib_reset_raster
+ */
 RTGRPBLIB_RASTER *rtgrpblib_create_raster(size_t width, size_t height);
+
+/**
+ * Reshape and clear a drawing buffer
+ * 
+ * @param   raster  The buffer to reshape and clear
+ * @param   width   The new width of the buffer
+ * @param   height  The new height of the buffer
+ * @return          0 on success, -1 on failure
+ * 
+ * @throws  EINVAL  `width` or `height` is zero
+ * @throws  EINVAL  The buffers new area size exceeds its original area size
+ */
 int rtgrpblib_reset_raster(RTGRPBLIB_RASTER *raster, size_t width, size_t height);
 
+
+/**
+ * Reconfigure a drawing buffer with a new draftness value
+ * 
+ * When drawing a curve, the size of each step the library
+ * takes will be proportional to the draftness value, but
+ * will also depend on other factors. Doubling the draftness
+ * value with halve (disregarind overheads) the time it takes
+ * to draw any given curve.
+ * 
+ * @param  raster     The drawing buffer to reconfigure
+ * @param  draftness  The new draftness value, must be positive
+ */
 void rtgrpblib_set_draftness(RTGRPBLIB_RASTER *raster, double draftness);
 
+
+/**
+ * Create an image of the drawings applied to a drawing buffer
+ * 
+ * All drawn shapes must be closed
+ * 
+ * Shapes that are drawn in the same angular direction add to
+ * each other, shapes that are drawn in opposite angular
+ * directions subtract from each other
+ * 
+ * @param  image    Output buffer, need not be initialised, but
+ *                  shall have an allocation size of `rowsize`
+ *                  multiplied by the height of `raster` and
+ *                  by `sizeof(double)`
+ * @param  rowsize  The number of elements in `image` per row,
+ *                  must be at least the width of `raster`
+ * @param  raster   The drawing buffer
+ * 
+ * @seealso  rtgrpblib_reset_raster
+ */
 void rtgrpblib_fill_shapes(double *restrict image, size_t rowsize, const RTGRPBLIB_RASTER *raster);
 
+
+/**
+ * Draw a line between two points
+ * 
+ * @param  raster  The drawing buffer
+ * @param  x1, y1  The starting point
+ * @param  x2, y2  The end point
+ */
 void rtgrpblib_draw_linear_bezier(RTGRPBLIB_RASTER *restrict raster,
                                   double x1, double y1,
                                   double x2, double y2);
 
+/**
+ * Draw a quadratic bézier curve
+ * 
+ * @param  raster  The drawing buffer
+ * @param  x1, y1  The starting point
+ * @param  x2, y2  The control point
+ * @param  x3, y3  The end point
+ */
 void rtgrpblib_draw_quadratic_bezier(RTGRPBLIB_RASTER *restrict raster,
                                      double x1, double y1,
                                      double x2, double y2,
                                      double x3, double y3);
 
-void rtgrpblib_draw_cubic_bezier(RTGRPBLIB_RASTER *restrict raster,
+/**
+ * Draw a cubic bézier curve
+ * 
+ * @param  raster  The drawing buffer
+ * @param  x1, y1  The starting point
+ * @param  x2, y2  The first control point
+ * @param  x3, y3  The second control point
+ * @param  x4, y4  The end point
+ */
+void rtgrpblib_draw_cubic_bezier(RTGRPBLIB_RASTER *restrict raster, /* needed for OpenType */
                                  double x1, double y1,
                                  double x2, double y2,
                                  double x3, double y3,
                                  double x4, double y4);
 
-void rtgrpblib_draw_circular_arc(RTGRPBLIB_RASTER *restrict raster,
+/**
+ * Draw a cricular arc
+ * 
+ * @param  raster      The drawing buffer
+ * @param  x0, y0      The midpoint of the ellipse
+ * @param  semiwidth   Half the width of the ellipse
+ * @param  semiheight  Half the height of the ellipse
+ * @param  start       The angular starting point of the arc, in radians
+ * @param  end         The angular end point of the arc, in radians
+ */
+void rtgrpblib_draw_circular_arc(RTGRPBLIB_RASTER *restrict raster, /* needed for outline stoking */
                                  double x0, double y0,
                                  double semiwidth, double semiheight,
                                  double start, double end);
 
-/* TODO add support for outlining */
-
 #endif
diff --git a/rtgrpblib_create_raster.c b/rtgrpblib_create_raster.c
index 89ebad6..cbc69f2 100644
--- a/rtgrpblib_create_raster.c
+++ b/rtgrpblib_create_raster.c
@@ -7,6 +7,7 @@ RASTER *
 rtgrpblib_create_raster(size_t width, size_t height)
 {
 	RASTER *raster;
+	size_t size;
 
 	if (!width || !height) {
 		errno = EINVAL;
@@ -15,7 +16,8 @@ rtgrpblib_create_raster(size_t width, size_t height)
 
 	if (width > (SIZE_MAX - offsetof(RASTER, cells)) / sizeof(*raster->cells) / height)
 		goto enomem;
-	raster = calloc(1, offsetof(RASTER, cells) + height * width * sizeof(*raster->cells));
+	size = width * height;
+	raster = calloc(1, offsetof(RASTER, cells) + size * sizeof(*raster->cells));
 	if (!raster) {
 	enomem:
 		errno = ENOMEM;
@@ -24,7 +26,8 @@ rtgrpblib_create_raster(size_t width, size_t height)
 
 	raster->width = width;
 	raster->height = height;
-	raster->draftness = 0.5;
+	raster->size = size;
+	raster->draftness = DEFAULT_DRAFTNESS;
 	return raster;
 }
 
@@ -34,7 +37,43 @@ rtgrpblib_create_raster(size_t width, size_t height)
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	RASTER *raster;
+	size_t i, n;
+
+	errno = 0;
+	ASSERT(!rtgrpblib_create_raster(0, 1));
+	ASSERT(errno == EINVAL);
+
+	errno = 0;
+	ASSERT(!rtgrpblib_create_raster(1, 0));
+	ASSERT(errno == EINVAL);
+
+	errno = 0;
+	ASSERT(!rtgrpblib_create_raster(0, 0));
+	ASSERT(errno == EINVAL);
+
+	errno = 0;
+	ASSERT(!rtgrpblib_create_raster(SIZE_MAX - offsetof(RASTER, cells) + 1, 1));
+	ASSERT(errno == ENOMEM);
+
+	errno = 0;
+	ASSERT(!rtgrpblib_create_raster(1, SIZE_MAX - offsetof(RASTER, cells) + 1));
+	ASSERT(errno == ENOMEM);
+
+	raster = rtgrpblib_create_raster(10, 20);
+	ASSERT(raster);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == raster->width * raster->height);
+	ASSERT(raster->draftness == DEFAULT_DRAFTNESS);
+	n = raster->width * raster->height;
+	for (i = 0; i < n; i++) {
+		ASSERT(!raster->cells[i].cell_coverage);
+		ASSERT(!raster->cells[i].opposite_coverage);
+	}
+
+	free(raster);
+	return 0;
 }
 
 #endif
diff --git a/rtgrpblib_reset_raster.c b/rtgrpblib_reset_raster.c
index 2cfef42..a3b81df 100644
--- a/rtgrpblib_reset_raster.c
+++ b/rtgrpblib_reset_raster.c
@@ -6,7 +6,7 @@
 int
 rtgrpblib_reset_raster(RASTER *raster, size_t width, size_t height)
 {
-	if (!width || !height || width > raster->width * raster->height / height) {
+	if (!width || !height || width > raster->size / height) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -23,7 +23,96 @@ rtgrpblib_reset_raster(RASTER *raster, size_t width, size_t height)
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	
+	RASTER *raster;
+	size_t i, n, size;
+
+	raster = rtgrpblib_create_raster(10, 20);
+	ASSERT(raster);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	raster->draftness = 10;
+	size = raster->width * raster->height;
+	ASSERT(raster->size == size);
+
+	errno = 0;
+	ASSERT(rtgrpblib_reset_raster(raster, 10, 21) == -1);
+	ASSERT(errno == EINVAL);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+
+	errno = 0;
+	ASSERT(rtgrpblib_reset_raster(raster, 11, 20) == -1);
+	ASSERT(errno == EINVAL);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+
+	errno = 0;
+	ASSERT(rtgrpblib_reset_raster(raster, 1, 0) == -1);
+	ASSERT(errno == EINVAL);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+
+	errno = 0;
+	ASSERT(rtgrpblib_reset_raster(raster, 0, 1) == -1);
+	ASSERT(errno == EINVAL);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+
+	errno = 0;
+	ASSERT(rtgrpblib_reset_raster(raster, 0, 0) == -1);
+	ASSERT(errno == EINVAL);
+	ASSERT(raster->width == 10);
+	ASSERT(raster->height == 20);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+
+	memset(raster->cells, 100, raster->size * sizeof(*raster->cells));
+	ASSERT(!rtgrpblib_reset_raster(raster, 5, 10));
+	ASSERT(raster->width == 5);
+	ASSERT(raster->height == 10);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+	n = raster->width * raster->height;
+	for (i = 0; i < n; i++) {
+		ASSERT(!raster->cells[i].cell_coverage);
+		ASSERT(!raster->cells[i].opposite_coverage);
+	}
+
+	memset(raster->cells, 100, raster->size * sizeof(*raster->cells));
+	ASSERT(!rtgrpblib_reset_raster(raster, 5, 30));
+	ASSERT(raster->width == 5);
+	ASSERT(raster->height == 30);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+	n = raster->width * raster->height;
+	for (i = 0; i < n; i++) {
+		ASSERT(!raster->cells[i].cell_coverage);
+		ASSERT(!raster->cells[i].opposite_coverage);
+	}
+
+	memset(raster->cells, 100, raster->size * sizeof(*raster->cells));
+	ASSERT(!rtgrpblib_reset_raster(raster, 15, 10));
+	ASSERT(raster->width == 15);
+	ASSERT(raster->height == 10);
+	ASSERT(raster->size == size);
+	ASSERT(raster->draftness == 10);
+	n = raster->width * raster->height;
+	for (i = 0; i < n; i++) {
+		ASSERT(!raster->cells[i].cell_coverage);
+		ASSERT(!raster->cells[i].opposite_coverage);
+	}
+
+	free(raster);
+	return 0;
 }
 
 #endif
diff --git a/rtgrpblib_set_draftness.c b/rtgrpblib_set_draftness.c
index dbdeed0..d35222f 100644
--- a/rtgrpblib_set_draftness.c
+++ b/rtgrpblib_set_draftness.c
@@ -15,7 +15,7 @@ rtgrpblib_set_draftness(RTGRPBLIB_RASTER *raster, double draftness)
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	return 0; /* why test something this trivial */
 }
 
 #endif
diff --git a/sorting.c b/sorting.c
index e4bfdaf..2738081 100644
--- a/sorting.c
+++ b/sorting.c
@@ -18,7 +18,33 @@ doublepcmp(const void *avp, const void *bvp)
 int
 main(void)
 {
-	return 0; /* TODO add test */
+	double a, b;
+
+	a = 1.0, b = 1.0;
+	ASSERT(doublepcmp(&a, &b) == 0);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	a = -1.0, b = 1.0;
+	ASSERT(doublepcmp(&a, &b) == -1);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	a = 1.0, b = -1.0;
+	ASSERT(doublepcmp(&a, &b) == +1);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	a = 0.0, b = 0.0;
+	ASSERT(doublepcmp(&a, &b) == 0);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	a = -1.0, b = 2.5;
+	ASSERT(doublepcmp(&a, &b) == -1);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	a = 1.0, b = -2.5;
+	ASSERT(doublepcmp(&a, &b) == +1);
+	ASSERT(doublepcmp(&b, &a) == -doublepcmp(&a, &b));
+
+	return 0;
 }