Improvements for character transformations

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

6 files changed, 78 insertions, 63 deletions

diff --git a/common.h b/common.h
index 787ec68..d8c4a56 100644
--- a/common.h
+++ b/common.h
@@ -36,8 +36,10 @@ struct libskrift_context {
 	char                       subpixel_horizontally;
 	char                       subpixel_vertically;
 	char                       subpixel_bgr;
-	double                     x_advancement;
-	double                     y_advancement;
+	double                     char_x_advancement;
+	double                     char_y_advancement;
+	double                     text_x_advancement;
+	double                     text_y_advancement;
 	double                     transformation[6];
 	size_t                     nfonts;
 	LIBSKRIFT_FONT            *fonts[];
diff --git a/demo.c b/demo.c
index c1a6488..e7d4eec 100644
--- a/demo.c
+++ b/demo.c
@@ -19,6 +19,7 @@ USAGE("[-b background-colour] [-f foreground-colour] [-a opacity] [-t character-
       "[-S smoothing-method[:subpixel-order]] [-H hiniting] [-o flags] ... [-s font-size] [-F font-file] "
       "[-D dpi-x:dpi-y | -D dpi] [-w width] [-h height] [-x x-position] [-y y-position] [text]");
 
+
 static uint8_t
 decode_hexbyte(char hi, char lo)
 {
@@ -28,6 +29,7 @@ decode_hexbyte(char hi, char lo)
 	return (uint8_t)ret;
 }
 
+
 static void
 parse_colour(const char *s, uint8_t *redp, uint8_t *greenp, uint8_t *bluep, uint8_t *alphap)
 {
@@ -67,6 +69,7 @@ invalid:
 	exit(1);
 }
 
+
 _LIBSKRIFT_GCC_ONLY(__attribute__((__pure__)))
 static uint16_t
 parse_uint16(const char *s)
@@ -84,6 +87,7 @@ parse_uint16(const char *s)
 	return ret;
 }
 
+
 _LIBSKRIFT_GCC_ONLY(__attribute__((__pure__)))
 static int16_t
 parse_int16(const char *s, const char **end)
@@ -111,6 +115,7 @@ parse_int16(const char *s, const char **end)
 	return ret;
 }
 
+
 static void
 parse_transformation(char *s, double matrix[6])
 {
@@ -277,6 +282,26 @@ parse_transformation(char *s, double matrix[6])
 #undef S0
 }
 
+
+static double
+apply_unit(double size, const char *unit, const struct libskrift_rendering *rendering, const char *unit_for)
+{
+	if (!strcmp(unit, "px"))
+		return size;
+	if (!strcmp(unit, "pt"))
+		return libskrift_points_to_pixels(size, rendering);
+	if (!strcmp(unit, "in"))
+		return libskrift_inches_to_pixels(size, rendering);
+	if (!strcmp(unit, "mm"))
+		return libskrift_millimeters_to_pixels(size, rendering);
+	if (!strcmp(unit, "cm"))
+		return libskrift_millimeters_to_pixels(size * 10, rendering);
+
+	fprintf(stderr, "%s: valid %s units are: 'px', 'pt', 'in', 'mm', 'cm'", argv0, unit_for);
+	exit(1);
+}
+
+
 int
 main(int argc, char *argv[])
 {
@@ -289,7 +314,8 @@ main(int argc, char *argv[])
 	double font_size = 72;
 	const char *font_size_unit = "pt";
 	const char *x_unit = "", *y_unit = "";
-	double height, opacity = .80f, xf, yf;
+	const char *kerning_unit = "", *interletter_spacing_unit = "";
+	double height, opacity = .80f, f;
 	size_t size, i;
 	char *end, *arg;
 	const char *text = TEST_TEXT;
@@ -441,15 +467,17 @@ main(int argc, char *argv[])
 	case 'k':
 		errno = 0;
 		rendering.kerning = strtod(ARG(), &end);
-		if (errno || *end)
+		if (errno)
 			usage();
+		kerning_unit = end;
 		break;
 
 	case 'i':
 		errno = 0;
 		rendering.interletter_spacing = strtod(ARG(), &end);
-		if (errno || *end)
+		if (errno)
 			usage();
+		interletter_spacing_unit = end;
 		break;
 
 	case 'g':
@@ -562,64 +590,41 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
+	if (*x_unit && strcmp(x_unit, "px")) {
+		f = (double)x;
+		f = apply_unit(f, x_unit, &rendering, "position");
+		x = (int16_t)f;
+	}
+
+	if (*y_unit && strcmp(y_unit, "px")) {
+		f = (double)y;
+		f = apply_unit(f, y_unit, &rendering, "position");
+		y = (int16_t)f;
+	}
+
+	if (*kerning_unit && strcmp(kerning_unit, "px")) {
+		f = rendering.kerning;
+		f = apply_unit(f, kerning_unit, &rendering, "spacing");
+		rendering.kerning = f;
+	}
+
+	if (*interletter_spacing_unit && strcmp(interletter_spacing_unit, "px")) {
+		f = rendering.interletter_spacing;
+		f = apply_unit(f, interletter_spacing_unit, &rendering, "spacing");
+		rendering.interletter_spacing = f;
+	}
+
 	if (libskrift_open_font_file(&font, font_file)) {
 		perror("libskrift_open_font_file");
 		return 1;
 	}
-	if (!strcmp(font_size_unit, "pt")) {
-		height = libskrift_points_to_pixels(font_size, &rendering);
-	} else if (!strcmp(font_size_unit, "px")) {
-		height = font_size;
-	} else if (!strcmp(font_size_unit, "in")) {
-		height = libskrift_inches_to_pixels(font_size, &rendering);
-	} else if (!strcmp(font_size_unit, "mm")) {
-		height = libskrift_millimeters_to_pixels(font_size, &rendering);
-	} else if (!strcmp(font_size_unit, "cm")) {
-		height = libskrift_millimeters_to_pixels(font_size * 10, &rendering);
-	} else {
-		fprintf(stderr, "%s: valid font size units are: 'pt', 'px', 'in', 'mm', 'cm'", argv0);
-		return 1;
-	}
+	height = apply_unit(font_size, font_size_unit, &rendering, "font size");
 	if (libskrift_create_context(&ctx, &font, 1, height, &rendering, NULL)) {
 		perror("libskrift_create_context");
 		return 1;
 	}
 	libskrift_close_font(font);
 
-	if (*x_unit && strcmp(x_unit, "px")) {
-		xf = (double)x;
-		if (!strcmp(x_unit, "pt")) {
-			xf = (int16_t)libskrift_points_to_pixels(xf, &rendering);
-		} else if (!strcmp(x_unit, "in")) {
-			xf = (int16_t)libskrift_inches_to_pixels(xf, &rendering);
-		} else if (!strcmp(x_unit, "mm")) {
-			xf = (int16_t)libskrift_millimeters_to_pixels(xf, &rendering);
-		} else if (!strcmp(x_unit, "cm")) {
-			xf = (int16_t)libskrift_millimeters_to_pixels(xf * 10, &rendering);
-		} else {
-			fprintf(stderr, "%s: valid position units are: 'pt', 'px', 'in', 'mm', 'cm'", argv0);
-			return 1;
-		}
-		x = (int16_t)xf;
-	}
-
-	if (*y_unit && strcmp(y_unit, "px")) {
-		yf = (double)y;
-		if (!strcmp(y_unit, "pt")) {
-			yf = libskrift_points_to_pixels(yf, &rendering);
-		} else if (!strcmp(y_unit, "in")) {
-			yf = libskrift_inches_to_pixels(yf, &rendering);
-		} else if (!strcmp(y_unit, "mm")) {
-			yf = libskrift_millimeters_to_pixels(yf, &rendering);
-		} else if (!strcmp(y_unit, "cm")) {
-			yf = libskrift_millimeters_to_pixels(yf * 10, &rendering);
-		} else {
-			fprintf(stderr, "%s: valid position units are: 'pt', 'px', 'in', 'mm', 'cm'", argv0);
-			return 1;
-		}
-		y = (int16_t)yf;
-	}
-
 	size = 4;
 	size *= (size_t)image.width;
 	size *= (size_t)image.height;
diff --git a/libskrift_create_context.c b/libskrift_create_context.c
index db6f8a4..a1d01e0 100644
--- a/libskrift_create_context.c
+++ b/libskrift_create_context.c
@@ -77,8 +77,10 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_
 
 	(*ctxp)->schrift_ctx.font   = fonts[0]->font;
 	(*ctxp)->schrift_ctx.yScale = height;
-	(*ctxp)->x_advancement      = 1;
-	(*ctxp)->y_advancement      = 0;
+	(*ctxp)->char_x_advancement = 1;
+	(*ctxp)->char_y_advancement = 0;
+	(*ctxp)->text_x_advancement = 1;
+	(*ctxp)->text_y_advancement = 0;
 	(*ctxp)->nfonts             = nfonts;
 	for (i = 0; i < nfonts; i++) {
 		(*ctxp)->fonts[i] = fonts[i];
@@ -126,8 +128,10 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_
 	    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];
-		(*ctxp)->y_advancement = (*ctxp)->rendering.text_transformation[3];
+		(*ctxp)->char_x_advancement = (*ctxp)->rendering.char_transformation[0];
+		(*ctxp)->char_y_advancement = (*ctxp)->rendering.char_transformation[3];
+		(*ctxp)->text_x_advancement = (*ctxp)->rendering.text_transformation[0];
+		(*ctxp)->text_y_advancement = (*ctxp)->rendering.text_transformation[3];
 		(*ctxp)->schrift_ctx.transformation_hook = transformation_hook;
 	}
 
diff --git a/libskrift_draw_text.c b/libskrift_draw_text.c
index 75645ba..e827159 100644
--- a/libskrift_draw_text.c
+++ b/libskrift_draw_text.c
@@ -18,7 +18,7 @@ libskrift_draw_text(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t text_length
 	struct libskrift_saved_grapheme saved = LIBSKRIFT_NO_SAVED_GRAPHEME;
 	struct libskrift_glyph *glyph;
 	char *buffer = NULL;
-	double xpos = 0, ypos = 0;
+	double xpos = 0, ypos = 0, advance;
 	ssize_t len;
 	int r;
 
@@ -44,8 +44,10 @@ libskrift_draw_text(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t text_length
 		}
 
 		r = libskrift_apply_glyph(ctx, glyph, colour, x, y, image);
-		xpos += (glyph->advance + ctx->rendering.interletter_spacing) * ctx->x_advancement;
-		ypos += (glyph->advance + ctx->rendering.interletter_spacing) * ctx->y_advancement;
+		advance = glyph->advance * ctx->char_x_advancement;
+		advance += ctx->rendering.interletter_spacing;
+		xpos += advance * ctx->text_x_advancement;
+		ypos += advance * ctx->text_y_advancement;
 		free(glyph);
 		if (r) {
 			free(buffer);
diff --git a/libskrift_get_cluster_glyph.c b/libskrift_get_cluster_glyph.c
index fbc3a18..6b3abaa 100644
--- a/libskrift_get_cluster_glyph.c
+++ b/libskrift_get_cluster_glyph.c
@@ -29,7 +29,8 @@ libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t tex
 	if (libskrift_get_grapheme_glyph(ctx, cp0, x, y, &glyph0))
 		return -1;
 
-	x += glyph0->advance;
+	x += glyph0->advance * ctx->char_x_advancement;
+	y += glyph0->advance * ctx->char_y_advancement;
 	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)) {
@@ -45,7 +46,8 @@ libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *ctx, const char *text, size_t tex
 			free(glyph0);
 			return -1;
 		}
-		x += glyph1->advance;
+		x += glyph1->advance * ctx->char_x_advancement;
+		y += glyph1->advance * ctx->char_y_advancement;
 
 		if (libskrift_merge_glyphs(ctx, glyph0, glyph1, &glyph2)) {
 			free(glyph0);
diff --git a/libskrift_get_grapheme_glyph.c b/libskrift_get_grapheme_glyph.c
index fa7a8c5..515e81d 100644
--- a/libskrift_get_grapheme_glyph.c
+++ b/libskrift_get_grapheme_glyph.c
@@ -38,7 +38,7 @@ libskrift_get_grapheme_glyph(LIBSKRIFT_CONTEXT *ctx, libskrift_codepoint_t codep
 	height = (uint16_t)(sft_chr.height + top + bottom) / vmul;
 	size  *= (size_t)width * (size_t)height;
 
-	*glyphp = malloc(offsetof(struct libskrift_glyph, image) + size);
+	*glyphp = malloc(FLEXSTRUCTSIZE(struct libskrift_glyph, image, size));
 	if (!*glyphp) {
 		free(sft_chr.image);
 		return -1;