minor fixes and cleanups, and update to use new version of libgrapheme and add text length parameter instead of using NUL-termination

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

14 files changed, 74 insertions, 66 deletions

diff --git a/LICENSE b/LICENSE
index 38e536c..c97d5c1 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 ISC License
 
-© 2020 Mattias Andrée <maandree@kth.se>
+© 2020, 2021 Mattias Andrée <maandree@kth.se>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above
diff --git a/README b/README
index 0067bc2..c34edbc 100644
--- a/README
+++ b/README
@@ -13,7 +13,7 @@ Currently implemented:
 	Subpixel rendering (RGB, BGR, both horizontal and vertical).
 
 	DPI support. (Points, inches, and millimeters can be
-	exactly converted pixels.)
+	exactly converted to pixels.)
 	(Both horizonal and vertical resolution can be specified.)
 
 	Drawing coloured text with 3 primaries, alpha and opacity,
@@ -78,7 +78,7 @@ Things that require new features in libschrift
 
 Out of scope:
 
-	Bidirection text.
+	Bidirectional text.
 
 	Text justification.
 
@@ -89,3 +89,5 @@ Out of scope:
 	Underline, overline, strike-thought, ...
 
 	Superscript and subscript.
+
+	Mathematical formulae formating.
diff --git a/common.h b/common.h
index dc9bcbd..787ec68 100644
--- a/common.h
+++ b/common.h
@@ -19,6 +19,9 @@
 
 #define LEN(ARR) (sizeof(ARR) / sizeof(*(ARR)))
 
+#define FLEXSTRUCTSIZE(STRUCT, FLEXARRAY, FLEXARRAY_LENGTH)\
+	(offsetof(STRUCT, FLEXARRAY) + (FLEXARRAY_LENGTH) * sizeof(*((STRUCT *)NULL)->FLEXARRAY))
+
 struct libskrift_font {
 	SFT_Font *font;
 	void     *memory_free;
diff --git a/demo.c b/demo.c
index 063721c..4920de1 100644
--- a/demo.c
+++ b/demo.c
@@ -54,7 +54,7 @@ main(void)
 		((uint8_t *)image.image)[i + 3] = 250U;
 	}
 
-	if (libskrift_draw_text(ctx, "hello world", &colour, 0, 300, &image) < 0) {
+	if (libskrift_draw_text(ctx, "hello world", strlen("hello world"), &colour, 0, 300, &image) < 0) {
 		perror("libskrift_draw_text");
 		return -1;
 	}
diff --git a/libskrift.h b/libskrift.h
index d587294..fc99142 100644
--- a/libskrift.h
+++ b/libskrift.h
@@ -140,6 +140,7 @@ struct libskrift_glyph {
 };
 
 struct libskrift_saved_grapheme {
+	int have_saved;
 	libskrift_codepoint_t cp;
 	size_t len;
 };
@@ -185,7 +186,7 @@ struct libskrift_colour {
 	.text_transformation                = {1, 0, 0,   0, 1, 0},\
 }
 
-#define LIBSKRIFT_NO_SAVED_GRAPHEME {0, 0}
+#define LIBSKRIFT_NO_SAVED_GRAPHEME {0, 0, 0}
 
 #define LIBSKRIFT_PREMULTIPLY(OPACITY, ALPHA, RED, GREEN, BLUE)\
 	{(OPACITY),\
@@ -254,8 +255,8 @@ const struct libskrift_rendering *libskrift_get_rendering_settings(LIBSKRIFT_CON
 _LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
 int libskrift_get_grapheme_glyph(LIBSKRIFT_CONTEXT *, libskrift_codepoint_t, double, double, struct libskrift_glyph **);
 
-_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 6))))
-ssize_t libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *, const char *, struct libskrift_saved_grapheme *,
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 7))))
+ssize_t libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *, const char *, size_t, struct libskrift_saved_grapheme *,
                                     double, double, struct libskrift_glyph **);
 
 _LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
@@ -266,8 +267,8 @@ _LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 6))))
 int libskrift_apply_glyph(LIBSKRIFT_CONTEXT *, const struct libskrift_glyph *, const struct libskrift_colour *,
                           int16_t, int16_t, struct libskrift_image *);
 
-_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 6))))
-int libskrift_draw_text(LIBSKRIFT_CONTEXT *, const char *, const struct libskrift_colour *,
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 7))))
+int libskrift_draw_text(LIBSKRIFT_CONTEXT *, const char *, size_t, const struct libskrift_colour *,
                         int16_t, int16_t, struct libskrift_image *);
 
 
diff --git a/libskrift_apply_glyph.c b/libskrift_apply_glyph.c
index 85e4bd2..3fc3fc5 100644
--- a/libskrift_apply_glyph.c
+++ b/libskrift_apply_glyph.c
@@ -95,7 +95,7 @@ libskrift_apply_glyph(LIBSKRIFT_CONTEXT *ctx, const struct libskrift_glyph *glyp
 	startc = (uint16_t)((int16_t)x1 - sx1);
 	startr = (uint16_t)((int16_t)y1 - sy1);
 
-	/* Post-last pixel in glyph to draw*/
+	/* Post-last pixel in glyph to draw */
 	endc = (uint16_t)((int16_t)x2 - sx1);
 	endr = (uint16_t)((int16_t)y2 - sy1);
 
diff --git a/libskrift_create_context.c b/libskrift_create_context.c
index 18cf961..db6f8a4 100644
--- a/libskrift_create_context.c
+++ b/libskrift_create_context.c
@@ -71,7 +71,7 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_
 		}
 	}
 
-	*ctxp = calloc(1, offsetof(LIBSKRIFT_CONTEXT, fonts) + nfonts * sizeof(*(*ctxp)->fonts));
+	*ctxp = calloc(1, FLEXSTRUCTSIZE(LIBSKRIFT_CONTEXT, fonts, nfonts));
 	if (!*ctxp)
 		return -1;
 
@@ -97,13 +97,13 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_
 		memcpy(&(*ctxp)->rendering, &default_rendering, sizeof(default_rendering));
 	}
 
-	(*ctxp)->rendering.struct_version      = LIBSKRIFT_RENDERING_STRUCT_VERSION;
-	(*ctxp)->rendering.hinting             = LIBSKRIFT_NONE;
-	(*ctxp)->rendering.flags              &= IMPLEMENTED_FLAGS;
-	(*ctxp)->rendering.flags              |= FORCED_FLAGS;
-	(*ctxp)->rendering.flags              |= LIBSKRIFT_REMOVE_GAMMA; /* libschrift does not add gamma */
-	(*ctxp)->rendering.grid_fineness       = 1;
-	(*ctxp)->rendering.kerning             = 0;
+	(*ctxp)->rendering.struct_version = LIBSKRIFT_RENDERING_STRUCT_VERSION;
+	(*ctxp)->rendering.hinting        = LIBSKRIFT_NONE;
+	(*ctxp)->rendering.flags         &= IMPLEMENTED_FLAGS;
+	(*ctxp)->rendering.flags         |= FORCED_FLAGS;
+	(*ctxp)->rendering.flags         |= LIBSKRIFT_REMOVE_GAMMA; /* libschrift does not add gamma */
+	(*ctxp)->rendering.grid_fineness  = 1;
+	(*ctxp)->rendering.kerning        = 0;
 
 	if (!(*ctxp)->rendering.smoothing)
 		(*ctxp)->rendering.smoothing = LIBSKRIFT_GREYSCALE;
@@ -113,17 +113,17 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_
 	(*ctxp)->schrift_ctx.hook_data = (*ctxp);
 	if (((*ctxp)->rendering.flags & TRANSFORMING_FLAGS) ||
 	    fpclassify((*ctxp)->rendering.char_transformation[0] - 1) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.char_transformation[1]) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.char_transformation[2]) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.char_transformation[3]) != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.char_transformation[1])     != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.char_transformation[2])     != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.char_transformation[3])     != FP_ZERO ||
 	    fpclassify((*ctxp)->rendering.char_transformation[4] - 1) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.char_transformation[5]) != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.char_transformation[5])     != FP_ZERO ||
 	    fpclassify((*ctxp)->rendering.text_transformation[0] - 1) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.text_transformation[1]) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.text_transformation[2]) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.text_transformation[3]) != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.text_transformation[1])     != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.text_transformation[2])     != FP_ZERO ||
+	    fpclassify((*ctxp)->rendering.text_transformation[3])     != FP_ZERO ||
 	    fpclassify((*ctxp)->rendering.text_transformation[4] - 1) != FP_ZERO ||
-	    fpclassify((*ctxp)->rendering.text_transformation[5]) != FP_ZERO) {
+	    fpclassify((*ctxp)->rendering.text_transformation[5])     != FP_ZERO) {
 		memcpy((*ctxp)->transformation, (*ctxp)->rendering.char_transformation, sizeof((*ctxp)->transformation));
 		libskrift_add_transformation((*ctxp)->transformation, (*ctxp)->rendering.text_transformation);
 		(*ctxp)->x_advancement = (*ctxp)->rendering.text_transformation[0];
diff --git a/libskrift_draw_text.c b/libskrift_draw_text.c
index 356468d..75645ba 100644
--- a/libskrift_draw_text.c
+++ b/libskrift_draw_text.c
@@ -2,45 +2,42 @@
 #include "common.h"
 
 static void
-reverse_text(const char *restrict text, char *restrict s, size_t off)
+reverse_text(const char *restrict text, size_t text_length, char *restrict s)
 {
-	size_t n;
-	s[off] = '\0';
-	for (; *text; text += n) {
-		off -= n = grapheme_len(text);
+	size_t n, off = text_length;
+	for (; text_length; text += n, text_length -= n) {
+		off -= n = grapheme_bytelen(text);
 		memcpy(&s[off], text, n);
 	}
 }
 
 int
-libskrift_draw_text(LIBSKRIFT_CONTEXT *ctx, const char *text, const struct libskrift_colour *colour,
-                    int16_t x, int16_t y, struct libskrift_image *image)
+libskrift_draw_text(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t text_length,
+                    const struct libskrift_colour *colour, int16_t x, int16_t y, struct libskrift_image *image)
 {
 	struct libskrift_saved_grapheme saved = LIBSKRIFT_NO_SAVED_GRAPHEME;
 	struct libskrift_glyph *glyph;
 	char *buffer = NULL;
 	double xpos = 0, ypos = 0;
 	ssize_t len;
-	size_t n;
 	int r;
 
 	if (ctx->rendering.flags & LIBSKRIFT_MIRROR_TEXT) {
-		n = strlen(text);
-		if (n < 1024) {
-			buffer = alloca(n + 1);
+		if (text_length < 1024) {
+			buffer = alloca(text_length + 1);
 		} else {
-			buffer = malloc(n + 1);
+			buffer = malloc(text_length + 1);
 			if (!buffer)
 				return -1;
 		}
-		reverse_text(text, buffer, n);
+		reverse_text(text, text_length, buffer);
 		text = buffer;
-		if (n < 1024)
+		if (text_length < 1024)
 			buffer = NULL;
 	}
 
-	for (; *text; text += len) {
-		len = libskrift_get_cluster_glyph(ctx, text, &saved, xpos, ypos, &glyph);
+	for (; text_length; text += len, text_length -= (size_t)len) {
+		len = libskrift_get_cluster_glyph(ctx, text, text_length, &saved, xpos, ypos, &glyph);
 		if (len < 0) {
 			free(buffer);
 			return -1;
diff --git a/libskrift_format_settings.c b/libskrift_format_settings.c
index aaa8255..fba2eed 100644
--- a/libskrift_format_settings.c
+++ b/libskrift_format_settings.c
@@ -32,5 +32,4 @@ const struct format_settings libskrift_format_settings[] = {
 	[LIBSKRIFT_RGB_LONG_DOUBLE]  = {3,  RGB,  sizeof(long double)},
 	[LIBSKRIFT_ARGB_LONG_DOUBLE] = {3, ARGB,  sizeof(long double)},
 	[LIBSKRIFT_RGBA_LONG_DOUBLE] = {3,  RGBA, sizeof(long double)}
-	/* REMEMBER that element count is specified in common.h */
 };
diff --git a/libskrift_get_cluster_glyph.c b/libskrift_get_cluster_glyph.c
index e8d5724..fbc3a18 100644
--- a/libskrift_get_cluster_glyph.c
+++ b/libskrift_get_cluster_glyph.c
@@ -4,8 +4,8 @@
 /* TODO try normalisation if not found, then try fallback fonts */
 
 ssize_t
-libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, struct libskrift_saved_grapheme *saved,
-                            double x, double y, struct libskrift_glyph **glyphp)
+libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t text_length,
+                            struct libskrift_saved_grapheme *saved, double x, double y, struct libskrift_glyph **glyphp)
 {
 	struct libskrift_glyph *glyph0, *glyph1, *glyph2;
 	uint32_t cp0, cp1;
@@ -14,36 +14,31 @@ libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, struct lib
 
 	*glyphp = NULL;
 
-	if (saved && saved->cp) {
+	if (!text_length) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (saved && saved->have_saved) {
 		cp0 = saved->cp;
 		len = saved->len;
 	} else {
-		len = grapheme_decode(text, &cp0);
-		if (!len) {
-			errno = EINVAL;
-			return -1;
-		}
+		len = grapheme_cp_decode(&cp0, (const void *)text, text_length);
 	}
 
 	if (libskrift_get_grapheme_glyph(ctx, cp0, x, y, &glyph0))
 		return -1;
 
 	x += glyph0->advance;
-	for (; cp0; cp0 = cp1, len += r) {
-		r = grapheme_decode(&text[len], &cp1);
-		if (!r) {
-			if (saved) {
-				saved->cp = 0;
-				saved->len = 0;
-			}
-			break;
-		}
+	for (; len < text_length; cp0 = cp1, len += r) {
+		r = grapheme_cp_decode(&cp1, (const void *)&text[len], text_length - len);
 		if (grapheme_boundary(cp0, cp1, &state)) {
 			if (saved) {
+				saved->have_saved = 1;
 				saved->cp = cp1;
 				saved->len = r;
 			}
-			break;
+			goto out;
 		}
 
 		if (libskrift_get_grapheme_glyph(ctx, cp1, x, y, &glyph1)) {
@@ -62,7 +57,13 @@ libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, struct lib
 		free(glyph1);
 		glyph0 = glyph2;
 	}
+	if (saved) {
+		saved->have_saved = 0;
+		saved->cp = 0;
+		saved->len = 0;
+	}
 
+out:
 	*glyphp = glyph0;
 
 	return (ssize_t)len;
diff --git a/libskrift_merge_glyphs.c b/libskrift_merge_glyphs.c
index 4df6f7a..820d0d4 100644
--- a/libskrift_merge_glyphs.c
+++ b/libskrift_merge_glyphs.c
@@ -20,7 +20,7 @@ libskrift_merge_glyphs(LIBSKRIFT_CONTEXT *ctx, const struct libskrift_glyph *gly
 		glyph2 = t;
 	}
 	if (!(glyph2->width | glyph2->height)) {
-		size = offsetof(struct libskrift_glyph, image) + glyph1->size;
+		size = FLEXSTRUCTSIZE(struct libskrift_glyph, image, glyph1->size);
 		*glyphp = calloc(1, size);
 		if (!*glyphp)
 			return -1;
@@ -47,7 +47,7 @@ libskrift_merge_glyphs(LIBSKRIFT_CONTEXT *ctx, const struct libskrift_glyph *gly
 	size *= width  = (uint16_t)(x2 - x1);
 	size *= height = (uint16_t)(y2 - y1);
 
-	*glyphp = calloc(1, offsetof(struct libskrift_glyph, image) + size);
+	*glyphp = calloc(1, FLEXSTRUCTSIZE(struct libskrift_glyph, image, size));
 	if (!*glyphp)
 		return -1;
 
diff --git a/libskrift_open_font.c b/libskrift_open_font.c
index 1eb8ff9..d829a66 100644
--- a/libskrift_open_font.c
+++ b/libskrift_open_font.c
@@ -43,8 +43,8 @@ libskrift_open_font(LIBSKRIFT_FONT **fontp, FILE *fp)
 		return -1;
 	}
 
-	(*fontp)->memory_free  = mem;
-	(*fontp)->memory_size  = size;
+	(*fontp)->memory_free = mem;
+	(*fontp)->memory_size = size;
 
 	return 0;
 }
diff --git a/libskrift_open_font_at.c b/libskrift_open_font_at.c
index 2927dea..8745991 100644
--- a/libskrift_open_font_at.c
+++ b/libskrift_open_font_at.c
@@ -4,7 +4,7 @@
 int
 libskrift_open_font_at(LIBSKRIFT_FONT **fontp, int dirfd, const char *path)
 {
-	int fd, ret;
+	int fd, ret, saved_errno;
 	if (!*path) {
 		return libskrift_open_font_fd(fontp, dirfd);
 	} else {
@@ -12,7 +12,9 @@ libskrift_open_font_at(LIBSKRIFT_FONT **fontp, int dirfd, const char *path)
 		if (fd < 0)
 			return -1;
 		ret = libskrift_open_font_fd(fontp, fd);
+		saved_errno = errno;
 		close(fd);
+		errno = saved_errno;
 		return ret;
 	}
 }
diff --git a/libskrift_open_font_fd.c b/libskrift_open_font_fd.c
index c00422e..e134cd8 100644
--- a/libskrift_open_font_fd.c
+++ b/libskrift_open_font_fd.c
@@ -13,6 +13,7 @@ libskrift_open_font_fd(LIBSKRIFT_FONT **fontp, int fd)
 
 	saved_errno = errno;
 	if (fstat(fd, &st) < 0 || !st.st_size || !S_ISREG(st.st_mode)) {
+	fallback:
 		for (;;) {
 			if (off + 2048 > size) {
 				size += 8192;
@@ -39,6 +40,8 @@ libskrift_open_font_fd(LIBSKRIFT_FONT **fontp, int fd)
 		errno = saved_errno;
 	} else {
 		mem = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+		if (mem == MAP_FAILED || !mem)
+			goto fallback;
 		size = (size_t)st.st_size;
 		mmapped = 1;
 	}