Add autohinting and autokerning renders flags and prepare for fallback fonts

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

5 files changed, 40 insertions, 19 deletions

diff --git a/common.h b/common.h
index fdc17f5..615e9c2 100644
--- a/common.h
+++ b/common.h
@@ -14,15 +14,6 @@
 #define MIN(A, B) ((A) < (B) ? (A) : (B))
 #define MAX(A, B) ((A) > (B) ? (A) : (B))
 
-struct libskrift_context {
-	LIBSKRIFT_FONT            *font;
-	struct libskrift_rendering rendering;
-	struct SFT                 schrift_ctx;
-	char                       subpixel_horizontally;
-	char                       subpixel_vertically;
-	char                       subpixel_bgr;
-};
-
 struct libskrift_font {
 	SFT_Font *font;
 	void     *memory_free;
@@ -30,3 +21,13 @@ struct libskrift_font {
 	size_t    memory_size;
 	size_t    refcount;
 };
+
+struct libskrift_context {
+	struct libskrift_rendering rendering;
+	struct SFT                 schrift_ctx;
+	char                       subpixel_horizontally;
+	char                       subpixel_vertically;
+	char                       subpixel_bgr;
+	size_t                     nfonts;
+	LIBSKRIFT_FONT            *fonts[];
+};
diff --git a/demo.c b/demo.c
index 79cf920..70708c7 100644
--- a/demo.c
+++ b/demo.c
@@ -25,7 +25,7 @@ main(void)
 		return -1;
 	}
 	height = libskrift_points_to_pixels(72, &rendering);
-	if (libskrift_create_context(&ctx, font, &rendering, height)) {
+	if (libskrift_create_context(&ctx, &font, 1, height, &rendering)) {
 		perror("libskrift_create_context");
 		return -1;
 	}
diff --git a/libskrift.h b/libskrift.h
index 0ec54fe..1fa0085 100644
--- a/libskrift.h
+++ b/libskrift.h
@@ -56,7 +56,10 @@ enum libskrift_hinting {
 #define LIBSKRIFT_REGRESS_TO_GRID     0x00000400U /* Combine with LIBSKRIFT_ADVANCE_TO_GRID for closest alternative */
 #define LIBSKRIFT_USE_SUBPIXEL_GRID   0x00000800U
 #define LIBSKRIFT_VERTICAL_TEXT       0x00001000U
-#define LIBSKRIFT_AUTOHINTING         0x00002000U
+#define LIBSKRIFT_AUTOHINTING         0x00002000U /* Use autohinter even if hint information exists */
+#define LIBSKRIFT_NO_AUTOHINTING      0x00004000U /* Use autohinter if no hint information exist */
+#define LIBSKRIFT_AUTOKERNING         0x00008000U /* Use autokerner even if kerning information exists */
+#define LIBSKRIFT_NO_AUTOKERNING      0x00010000U /* Use autokerner if no kerning information exist */
 
 struct libskrift_rendering {
 	int struct_version;
@@ -164,7 +167,7 @@ void libskrift_close_font(LIBSKRIFT_FONT *);
 
 
 _LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2))))
-int libskrift_create_context(LIBSKRIFT_CONTEXT **, LIBSKRIFT_FONT *, const struct libskrift_rendering *, double);
+int libskrift_create_context(LIBSKRIFT_CONTEXT **, LIBSKRIFT_FONT **, size_t, double, const struct libskrift_rendering *);
 
 void libskrift_free_context(LIBSKRIFT_CONTEXT *);
 
diff --git a/libskrift_create_context.c b/libskrift_create_context.c
index 9ebec24..4adf179 100644
--- a/libskrift_create_context.c
+++ b/libskrift_create_context.c
@@ -1,8 +1,13 @@
 /* See LICENSE file for copyright and license details. */
 #include "common.h"
 
+#define FORCED_FLAGS (LIBSKRIFT_NO_LIGATURES   |\
+                      LIBSKRIFT_NO_AUTOHINTING |\
+                      LIBSKRIFT_NO_AUTOKERNING)
+
 #define IMPLEMENTED_FLAGS (LIBSKRIFT_CORRECT_GAMMA |\
-                           LIBSKRIFT_REMOVE_GAMMA) /* libschrift does not add gamma, so not handling is required */
+                           LIBSKRIFT_REMOVE_GAMMA  |\
+                           FORCED_FLAGS) /* libschrift does not add gamma, so not handling is required */
 
 #define HAVE_MULTIPLE_FLAGS(HAVE, CHECK) (((HAVE) & (CHECK)) & (((HAVE) & (CHECK)) - 1))
 
@@ -12,8 +17,16 @@
 static const struct libskrift_rendering default_rendering = LIBSKRIFT_DEFAULT_RENDERING;
 
 int
-libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT *font, const struct libskrift_rendering *rendering, double height)
+libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT **fonts, size_t nfonts, double height,
+                         const struct libskrift_rendering *rendering)
 {
+	size_t i;
+
+	if (!nfonts) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	if (rendering) {
 		if (HAVE_MULTIPLE_FLAGS(rendering->flags, LIBSKRIFT_CORRECT_GAMMA | LIBSKRIFT_REMOVE_GAMMA) ||
 		    !rendering->grid_fineness) {
@@ -22,13 +35,16 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT *font, const s
 		}
 	}
 
-	*ctxp = calloc(1, sizeof(**ctxp));
+	*ctxp = calloc(1, offsetof(LIBSKRIFT_CONTEXT, fonts) + nfonts * sizeof(*(*ctxp)->fonts));
 	if (!*ctxp)
 		return -1;
 
-	(*ctxp)->font               = font;
-	(*ctxp)->schrift_ctx.font   = font->font;
+	(*ctxp)->schrift_ctx.font   = fonts[0]->font;
 	(*ctxp)->schrift_ctx.yScale = height;
+	for (i = 0; i < nfonts; i++) {
+		(*ctxp)->fonts[i] = fonts[i];
+		fonts[i]->refcount += 1;
+	}
 
 	if (rendering) {
 		memcpy(&(*ctxp)->rendering, rendering, sizeof(*rendering));
@@ -47,6 +63,7 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT *font, const s
 	(*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.grid_fineness       = 1;
 	(*ctxp)->rendering.kerning             = 0;
 	(*ctxp)->rendering.interletter_spacing = 0;
@@ -78,6 +95,5 @@ libskrift_create_context(LIBSKRIFT_CONTEXT **ctxp, LIBSKRIFT_FONT *font, const s
 		}
 	}
 
-	font->refcount += 1;
 	return 0;
 }
diff --git a/libskrift_free_context.c b/libskrift_free_context.c
index 2375c05..68ac14d 100644
--- a/libskrift_free_context.c
+++ b/libskrift_free_context.c
@@ -5,7 +5,8 @@ void
 libskrift_free_context(LIBSKRIFT_CONTEXT *ctx)
 {
 	if (ctx) {
-		libskrift_close_font(ctx->font);
+		while (ctx->nfonts--)
+			libskrift_close_font(ctx->fonts[ctx->nfonts]);
 		free(ctx);
 	}
 }