ass_render.c

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// -*- c-basic-offset: 8; indent-tabs-mode: t -*-
// vim:ts=8:sw=8:noet:ai:
/*
  Copyright (C) 2006 Evgeniy Stepanov <[e-mail]>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/

#include "config.h"

#include <assert.h>
#include <math.h>
#include <inttypes.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_STROKER_H
#include FT_GLYPH_H
#include FT_SYNTHESIS_H

#include "mputils.h"

#include "ass.h"
#include "ass_font.h"
#include "ass_bitmap.h"
#include "ass_cache.h"
#include "ass_utils.h"
#include "ass_fontconfig.h"
#include "ass_library.h"

#define MAX_GLYPHS 1000
#define MAX_LINES 100

static int last_render_id = 0;

typedef struct ass_settings_s {
	int frame_width;
	int frame_height;
	double font_size_coeff; // font size multiplier
	double line_spacing; // additional line spacing (in frame pixels)
	int top_margin; // height of top margin. Everything except toptitles is shifted down by top_margin.
	int bottom_margin; // height of bottom margin. (frame_height - top_margin - bottom_margin) is original video height.
	int left_margin;
	int right_margin;
	int use_margins; // 0 - place all subtitles inside original frame
	                 // 1 - use margins for placing toptitles and subtitles
	double aspect; // frame aspect ratio, d_width / d_height.
	ass_hinting_t hinting;

	char* default_font;
	char* default_family;
} ass_settings_t;

// a rendered event
typedef struct event_images_s {
	ass_image_t* imgs;
	int top, height;
	int detect_collisions;
	int shift_direction;
	ass_event_t* event;
} event_images_t;

struct ass_renderer_s {
	ass_library_t* library;
	FT_Library ftlibrary;
	fc_instance_t* fontconfig_priv;
	ass_settings_t settings;
	int render_id;
	ass_synth_priv_t* synth_priv;

	ass_image_t* images_root; // rendering result is stored here
	ass_image_t* prev_images_root;

	event_images_t* eimg; // temporary buffer for sorting rendered events
	int eimg_size; // allocated buffer size
};

typedef enum {EF_NONE = 0, EF_KARAOKE, EF_KARAOKE_KF, EF_KARAOKE_KO} effect_t;

// describes a glyph
// glyph_info_t and text_info_t are used for text centering and word-wrapping operations
typedef struct glyph_info_s {
	unsigned symbol;
	FT_Glyph glyph;
	FT_Glyph outline_glyph;
	bitmap_t* bm; // glyph bitmap
	bitmap_t* bm_o; // outline bitmap
	bitmap_t* bm_s; // shadow bitmap
	FT_BBox bbox;
	FT_Vector pos;
	char linebreak; // the first (leading) glyph of some line ?
	uint32_t c[4]; // colors
	FT_Vector advance; // 26.6
	effect_t effect_type;
	int effect_timing; // time duration of current karaoke word
	                   // after process_karaoke_effects: distance in pixels from the glyph origin.
	                   // part of the glyph to the left of it is displayed in a different color.
	int effect_skip_timing; // delay after the end of last karaoke word
	int asc, desc; // font max ascender and descender
//	int height;
	int be; // blur edges
	int shadow;
	double frx, fry, frz; // rotation
	
	bitmap_hash_key_t hash_key;
} glyph_info_t;

typedef struct line_info_s {
	int asc, desc;
} line_info_t;

typedef struct text_info_s {
	glyph_info_t* glyphs;
	int length;
	line_info_t lines[MAX_LINES];
	int n_lines;
	int height;
} text_info_t;


// Renderer state.
// Values like current font face, color, screen position, clipping and so on are stored here.
typedef struct render_context_s {
	ass_event_t* event;
	ass_style_t* style;
	
	ass_font_t* font;
	char* font_path;
	double font_size;
	
	FT_Stroker stroker;
	int alignment; // alignment overrides go here; if zero, style value will be used
	double frx, fry, frz;
	enum {	EVENT_NORMAL, // "normal" top-, sub- or mid- title
		EVENT_POSITIONED, // happens after pos(,), margins are ignored
		EVENT_HSCROLL, // "Banner" transition effect, text_width is unlimited
		EVENT_VSCROLL // "Scroll up", "Scroll down" transition effects
		} evt_type;
	int pos_x, pos_y; // position
	int org_x, org_y; // origin
	char have_origin; // origin is explicitly defined; if 0, get_base_point() is used
	double scale_x, scale_y;
	double hspacing; // distance between letters, in pixels
	double border; // outline width
	uint32_t c[4]; // colors(Primary, Secondary, so on) in RGBA
	int clip_x0, clip_y0, clip_x1, clip_y1;
	char detect_collisions;
	uint32_t fade; // alpha from \fad
	char be; // blur edges
	int shadow;

	effect_t effect_type;
	int effect_timing;
	int effect_skip_timing;

	enum { SCROLL_LR, // left-to-right
	       SCROLL_RL,
	       SCROLL_TB, // top-to-bottom
	       SCROLL_BT
	       } scroll_direction; // for EVENT_HSCROLL, EVENT_VSCROLL
	int scroll_shift;

	// face properties
	char* family;
	unsigned bold;
	unsigned italic;
	
} render_context_t;

// frame-global data
typedef struct frame_context_s {
	ass_renderer_t* ass_priv;
	int width, height; // screen dimensions
	int orig_height; // frame height ( = screen height - margins )
	int orig_width; // frame width ( = screen width - margins )
	ass_track_t* track;
	long long time; // frame's timestamp, ms
	double font_scale;
	double font_scale_x; // x scale applied to all glyphs to preserve text aspect ratio
	double border_scale;
} frame_context_t;

static ass_renderer_t* ass_renderer;
static ass_settings_t* global_settings;
static text_info_t text_info;
static render_context_t render_context;
static frame_context_t frame_context;

struct render_priv_s {
	int top, height;
	int render_id;
};

static void ass_lazy_track_init(void)
{
	ass_track_t* track = frame_context.track;
	if (track->PlayResX && track->PlayResY)
		return;
	if (!track->PlayResX && !track->PlayResY) {
		mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_NeitherPlayResXNorPlayResYDefined);
		track->PlayResX = 384;
		track->PlayResY = 288;
	} else {
		double orig_aspect = (global_settings->aspect * frame_context.height * frame_context.orig_width) /
			frame_context.orig_height / frame_context.width;
		if (!track->PlayResY) {
			track->PlayResY = track->PlayResX / orig_aspect + .5;
			mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_PlayResYUndefinedSettingY, track->PlayResY);
		} else if (!track->PlayResX) {
			track->PlayResX = track->PlayResY * orig_aspect + .5;
			mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_PlayResXUndefinedSettingX, track->PlayResX);
		}
	}
}

ass_renderer_t* ass_renderer_init(ass_library_t* library)
{
	int error;
	FT_Library ft;
	ass_renderer_t* priv = 0;
	
	memset(&render_context, 0, sizeof(render_context));
	memset(&frame_context, 0, sizeof(frame_context));
	memset(&text_info, 0, sizeof(text_info));

	error = FT_Init_FreeType( &ft );
	if ( error ) { 
		mp_msg(MSGT_ASS, MSGL_FATAL, MSGTR_LIBASS_FT_Init_FreeTypeFailed);
		goto ass_init_exit;
	}

	priv = calloc(1, sizeof(ass_renderer_t));
	if (!priv) {
		FT_Done_FreeType(ft);
		goto ass_init_exit;
	}

	priv->synth_priv = ass_synth_init();

	priv->library = library;
	priv->ftlibrary = ft;
	// images_root and related stuff is zero-filled in calloc
	
	ass_font_cache_init();
	ass_bitmap_cache_init();
	ass_glyph_cache_init();

	text_info.glyphs = calloc(MAX_GLYPHS, sizeof(glyph_info_t));
	
ass_init_exit:
	if (priv) mp_msg(MSGT_ASS, MSGL_INFO, MSGTR_LIBASS_Init);
	else mp_msg(MSGT_ASS, MSGL_ERR, MSGTR_LIBASS_InitFailed);

	return priv;
}

void ass_renderer_done(ass_renderer_t* priv)
{
	ass_font_cache_done();
	ass_bitmap_cache_done();
	ass_glyph_cache_done();
	if (render_context.stroker) {
		FT_Stroker_Done(render_context.stroker);
		render_context.stroker = 0;
	}
	if (priv && priv->ftlibrary) FT_Done_FreeType(priv->ftlibrary);
	if (priv && priv->fontconfig_priv) fontconfig_done(priv->fontconfig_priv);
	if (priv && priv->synth_priv) ass_synth_done(priv->synth_priv);
	if (priv && priv->eimg) free(priv->eimg);
	if (priv) free(priv);
	if (text_info.glyphs) free(text_info.glyphs);
}

/**
 * \brief Create a new ass_image_t
 * Parameters are the same as ass_image_t fields.
 */
static ass_image_t* my_draw_bitmap(unsigned char* bitmap, int bitmap_w, int bitmap_h, int stride, int dst_x, int dst_y, uint32_t color)
{
	ass_image_t* img = calloc(1, sizeof(ass_image_t));
	
	img->w = bitmap_w;
	img->h = bitmap_h;
	img->stride = stride;
	img->bitmap = bitmap;
	img->color = color;
	img->dst_x = dst_x;
	img->dst_y = dst_y;

	return img;
}

/**
 * \brief convert bitmap glyph into ass_image_t struct(s)
 * \param bit freetype bitmap glyph, FT_PIXEL_MODE_GRAY
 * \param dst_x bitmap x coordinate in video frame
 * \param dst_y bitmap y coordinate in video frame
 * \param color first color, RGBA
 * \param color2 second color, RGBA
 * \param brk x coordinate relative to glyph origin, color is used to the left of brk, color2 - to the right
 * \param tail pointer to the last image's next field, head of the generated list should be stored here
 * \return pointer to the new list tail
 * Performs clipping. Uses my_draw_bitmap for actual bitmap convertion.
 */
static ass_image_t** render_glyph(bitmap_t* bm, int dst_x, int dst_y, uint32_t color, uint32_t color2, int brk, ass_image_t** tail)
{
	// brk is relative to dst_x
	// color = color left of brk
	// color2 = color right of brk
	int b_x0, b_y0, b_x1, b_y1; // visible part of the bitmap
	int clip_x0, clip_y0, clip_x1, clip_y1;
	int tmp;
	ass_image_t* img;

	dst_x += bm->left;
	dst_y += bm->top;
	brk -= bm->left;
	
	// clipping
	clip_x0 = render_context.clip_x0;
	clip_y0 = render_context.clip_y0;
	clip_x1 = render_context.clip_x1;
	clip_y1 = render_context.clip_y1;
	b_x0 = 0;
	b_y0 = 0;
	b_x1 = bm->w;
	b_y1 = bm->h;
	
	tmp = dst_x - clip_x0;
	if (tmp < 0) {
		mp_msg(MSGT_ASS, MSGL_DBG2, "clip left\n");
		b_x0 = - tmp;
	}
	tmp = dst_y - clip_y0;
	if (tmp < 0) {
		mp_msg(MSGT_ASS, MSGL_DBG2, "clip top\n");
		b_y0 = - tmp;
	}
	tmp = clip_x1 - dst_x - bm->w;
	if (tmp < 0) {
		mp_msg(MSGT_ASS, MSGL_DBG2, "clip right\n");
		b_x1 = bm->w + tmp;
	}
	tmp = clip_y1 - dst_y - bm->h;
	if (tmp < 0) {
		mp_msg(MSGT_ASS, MSGL_DBG2, "clip bottom\n");
		b_y1 = bm->h + tmp;
	}
	
	if ((b_y0 >= b_y1) || (b_x0 >= b_x1))
		return tail;

	if (brk > b_x0) { // draw left part
		if (brk > b_x1) brk = b_x1;
		img = my_draw_bitmap(bm->buffer + bm->w * b_y0 + b_x0, 
			brk - b_x0, b_y1 - b_y0, bm->w,
			dst_x + b_x0, dst_y + b_y0, color);
		*tail = img;
		tail = &img->next;
	}
	if (brk < b_x1) { // draw right part
		if (brk < b_x0) brk = b_x0;
		img = my_draw_bitmap(bm->buffer + bm->w * b_y0 + brk, 
			b_x1 - brk, b_y1 - b_y0, bm->w,
			dst_x + brk, dst_y + b_y0, color2);
		*tail = img;
		tail = &img->next;
	}
	return tail;
}

/**
 * \brief Convert text_info_t struct to ass_image_t list
 * Splits glyphs in halves when needed (for \kf karaoke).
 */
static ass_image_t* render_text(text_info_t* text_info, int dst_x, int dst_y)
{
	int pen_x, pen_y;
	int i;
	bitmap_t* bm;
	ass_image_t* head;
	ass_image_t** tail = &head;

	for (i = 0; i < text_info->length; ++i) {
		glyph_info_t* info = text_info->glyphs + i;
		if ((info->symbol == 0) || (info->symbol == '\n') || !info->bm_s || (info->shadow == 0))
			continue;

		pen_x = dst_x + info->pos.x + info->shadow;
		pen_y = dst_y + info->pos.y + info->shadow;
		bm = info->bm_s;

		tail = render_glyph(bm, pen_x, pen_y, info->c[3], 0, 1000000, tail);
	}

	for (i = 0; i < text_info->length; ++i) {
		glyph_info_t* info = text_info->glyphs + i;
		if ((info->symbol == 0) || (info->symbol == '\n') || !info->bm_o)
			continue;

		pen_x = dst_x + info->pos.x;
		pen_y = dst_y + info->pos.y;
		bm = info->bm_o;
		
		if ((info->effect_type == EF_KARAOKE_KO) && (info->effect_timing <= info->bbox.xMax)) {
			// do nothing
		} else
			tail = render_glyph(bm, pen_x, pen_y, info->c[2], 0, 1000000, tail);
	}
	for (i = 0; i < text_info->length; ++i) {
		glyph_info_t* info = text_info->glyphs + i;
		if ((info->symbol == 0) || (info->symbol == '\n') || !info->bm)
			continue;

		pen_x = dst_x + info->pos.x;
		pen_y = dst_y + info->pos.y;
		bm = info->bm;

		if ((info->effect_type == EF_KARAOKE) || (info->effect_type == EF_KARAOKE_KO)) {
			if (info->effect_timing > info->bbox.xMax)
				tail = render_glyph(bm, pen_x, pen_y, info->c[0], 0, 1000000, tail);
			else
				tail = render_glyph(bm, pen_x, pen_y, info->c[1], 0, 1000000, tail);
		} else if (info->effect_type == EF_KARAOKE_KF) {
			tail = render_glyph(bm, pen_x, pen_y, info->c[0], info->c[1], info->effect_timing, tail);
		} else
			tail = render_glyph(bm, pen_x, pen_y, info->c[0], 0, 1000000, tail);
	}