First commit

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

1 files changed, 183 insertions, 0 deletions

diff --git a/libskrift.h b/libskrift.h
new file mode 100644
index 0000000..5c2e937
--- /dev/null
+++ b/libskrift.h
@@ -0,0 +1,183 @@
+/* See LICENSE file for copyright and license details. */
+#ifndef LIBSKRIFT_H
+#define LIBSKRIFT_H 1
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#if defined(__GNUC__)
+# define _LIBSKRIFT_GCC_ONLY(...) __VA_ARGS__
+#else
+# define _LIBSKRIFT_GCC_ONLY(...)
+#endif
+
+
+#define LIBSKRIFT_RENDERING_STRUCT_VERSION 0
+
+#define LIBSKRIFT_NONE 0
+
+typedef struct libskrift_context LIBSKRIFT_CONTEXT;
+typedef struct libskrift_font LIBSKRIFT_FONT;
+typedef uint_least32_t libskrift_codepoint_t;
+
+
+enum libskrift_subpixel_order {
+	LIBSKRIFT_OTHER, /* LIBSKRIFT_NONE */
+	LIBSKRIFT_RGB,
+	LIBSKRIFT_BGR,
+	LIBSKRIFT_VRGB,
+	LIBSKRIFT_VBGR
+};
+
+enum libskrift_smoothing {
+	LIBSKRIFT_MONOCHROME, /* LIBSKRIFT_NONE */
+	LIBSKRIFT_GREYSCALE,
+	LIBSKRIFT_SUBPIXEL
+};
+
+enum libskrift_hinting {
+	LIBSKRIFT_UNHINTED = 0, /* LIBSKRIFT_NONE */
+	LIBSKRIFT_SLIGHT   = 25,
+	LIBSKRIFT_MEDIUM   = 50,
+	LIBSKRIFT_FULL     = 100
+};
+
+enum libskrift_rendering_flags {
+	LIBSKRIFT_CORRECT_GAMMA       = 0x0001,
+	LIBSKRIFT_REMOVE_GAMMA        = 0x0002,
+	LIBSKRIFT_Y_INCREASES_UPWARDS = 0x0004, /* SFT_DOWNWARD_Y otherwise */
+	LIBSKRIFT_FLIP_TEXT           = 0x0008,
+	LIBSKRIFT_MIRROR_TEXT         = 0x0010,
+	LIBSKRIFT_MIRROR_CHARS        = 0x0020,
+	LIBSKRIFT_TRANSPOSE_TEXT      = 0x0040,
+	LIBSKRIFT_TRANSPOSE_CHARS     = 0x0080,
+	LIBSKRIFT_NO_LIGATURES        = 0x0100,
+	LIBSKRIFT_ADVANCE_TO_GRID     = 0x0200,
+	LIBSKRIFT_REGRESS_TO_GRID     = 0x0400, /* Combine with LIBSKRIFT_ADVANCE_TO_GRID for closest alternative */
+	LIBSKRIFT_USE_SUBPIXEL_GRID   = 0x0800
+};
+
+struct libskrift_rendering {
+	int struct_version;
+	enum libskrift_subpixel_order  subpixel_order;
+	enum libskrift_smoothing       smoothing;
+	enum libskrift_hinting         hinting;
+	enum libskrift_rendering_flags flags;
+	double horizontal_dpi;
+	double vertical_dpi;
+	double kerning;
+	double interletter_spacing;
+	double prestroke_transformation_rotation[4];
+	double left_transformation[6];
+	double right_transformation[6];
+	double top_transformation[6];
+	double bottom_transformation[6];
+	double poststroke_transformation_rotation[4];
+	double char_transformation[6];
+	double text_transformation[6];
+};
+
+struct libskrift_glyph {
+	double   advance;
+	int16_t  x;
+	int16_t  y;
+	uint16_t width;
+	uint16_t height;
+	size_t   size;
+	uint8_t  image[];
+};
+
+struct libskrift_saved_grapheme {
+	libskrift_codepoint_t cp;
+	size_t len;
+};
+
+
+#define LIBSKRIFT_DEFAULT_RENDERING {\
+	.struct_version                     = LIBSKRIFT_RENDERING_STRUCT_VERSION,\
+	.subpixel_order                     = LIBSKRIFT_NONE,\
+	.smoothing                          = LIBSKRIFT_GREYSCALE,\
+	.hinting                            = LIBSKRIFT_FULL,\
+	.flags                              = 0,\
+	.horizontal_dpi                     = (double)1920 * 254 / 5180,\
+	.vertical_dpi                       = (double)1200 * 254 / 3240,\
+	.kerning                            = 1,\
+	.interletter_spacing                = 0,\
+	.prestroke_transformation_rotation  = {1, 0,      0, 1},\
+	.left_transformation                = {1, 0, 0,   0, 1, 0},\
+	.right_transformation               = {1, 0, 0,   0, 1, 0},\
+	.top_transformation                 = {1, 0, 0,   0, 1, 0},\
+	.bottom_transformation              = {1, 0, 0,   0, 1, 0},\
+	.poststroke_transformation_rotation = {1, 0,      0, 1},\
+	.char_transformation                = {1, 0, 0,   0, 1, 0},\
+	.text_transformation                = {1, 0, 0,   0, 1, 0},\
+}
+
+#define LIBSKRIFT_NO_SAVED_GRAPHEME {0, 0}
+
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__)))
+inline double
+libskrift_calculate_dpi(double pixels, double millimeters)
+{
+	return pixels * 254 / 10 / millimeters;
+}
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__)))
+inline double
+libskrift_inches_to_pixels(double inches, const struct libskrift_rendering *rendering)
+{
+	return inches * rendering->vertical_dpi;
+}
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__)))
+inline double
+libskrift_millimeters_to_pixels(double millimeters, const struct libskrift_rendering *rendering)
+{
+	return millimeters * 10 / 254 * rendering->vertical_dpi;
+}
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__)))
+inline double
+libskrift_points_to_pixels(double points, const struct libskrift_rendering *rendering)
+{
+	return points / 72 * rendering->vertical_dpi;
+}
+
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
+int libskrift_open_font_file(LIBSKRIFT_FONT **, const char *);
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
+int libskrift_open_font_mem(LIBSKRIFT_FONT **, const void *, size_t);
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
+int libskrift_open_font_fd(LIBSKRIFT_FONT **, int);
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
+int libskrift_open_font(LIBSKRIFT_FONT **, FILE *);
+
+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);
+
+void libskrift_free_context(LIBSKRIFT_CONTEXT *);
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__, __returns_nonnull__, __warn_unused_result__, __const__)))
+const struct libskrift_rendering *libskrift_get_rendering_settings(LIBSKRIFT_CONTEXT *);
+
+
+_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 *,
+                                    double, double, struct libskrift_glyph **);
+
+_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__)))
+int libskrift_merge_glyphs(LIBSKRIFT_CONTEXT *, struct libskrift_glyph *, struct libskrift_glyph *, struct libskrift_glyph **);
+
+#endif