img.c

ELinks is an advanced and well-established feature-rich text mode web (HTTP/FTP/..) browser. ELinks

/* img.c
 * Generic image decoding and PNG and JPG decoders.
 * (c) 2002 Karel 'Clock' Kulhavy
 * This is a part of the Links program, released under GPL.
 
 * Used in graphics mode of Links only
 TODO: odstranit zbytecne ditherovani z strip_optimized header_dimensions_known,
       protoze pozadi obrazku musi byt stejne jako pozadi stranky, a to se nikdy
       neditheruje, protoze je to vzdy jednolita barva. Kdyz uz to nepujde
       odstranit tak tam aspon dat fixne zaokrouhlovani.
 TODO: pouzit get_filled_bitmap az bude napsany k optimalizaci zadavani
       grafickych dat do X serveru z hlediska zaalokovane pameti.
 TODO: dodelat stripy do jpegu a png a tiff.
 */

#include "links.h"

#ifdef G

#ifdef HAVE_ENDIAN_H
/* Max von Sydow */
#include <endian.h>
#endif

#ifdef HAVE_JPEG
#include <jpeglib.h>
#endif

struct decoded_image {
	int bla;
};

#define RESTART_SIZE 8192
/* Size of biggest chunk of compressed data that is processed in one run */


/* End of decoder structs */

struct g_object_image *global_goi;
struct cached_image *global_cimg;
int end_callback_hit;
#endif /* #ifdef G */
int dither_images=1;
#ifdef G

/* prototypes */
int is_image_size_sane(int x, int y);
void destroy_decoder (struct cached_image *);
void img_destruct_image(struct g_object *);
int img_scale_h(unsigned scale, int);
int img_scale_v(unsigned scale, int);
unsigned short *buffer_to_16(unsigned short *, struct cached_image *, unsigned char *, int);
void r3l0ad(struct cached_image *, struct g_object_image *);
void type(struct cached_image *, unsigned char *);
int img_process_download(struct g_object_image *, struct f_data_c *);
int get_foreground(int);
void draw_frame_mark (struct graphics_driver *, struct graphics_device *, int, int, int, int, long, long, int);
void update_bitmap(struct cached_image *);
void img_draw_image (struct f_data_c *, struct g_object_image *, int, int);
void find_or_make_cached_image(struct g_object_image *, unsigned char *, int);
void buffer_to_bitmap(struct cached_image *);

int is_image_size_sane(int x, int y)
{
	unsigned a = (unsigned)x * (unsigned)y * 6;
	if (y && a / (unsigned)y / 6 != (unsigned)x) return 0;
	return a < MAXINT;
}

/* This is a dummy */
void img_draw_decoded_image(struct graphics_device *dev, struct decoded_image *d, int x, int y, int xw, int yw, int xo, int yo)
{
}

/* This is a dummy */
void img_release_decoded_image(struct decoded_image *d)
{
	mem_free(d);
}

/* mem_free(cimg->decoder) */
void destroy_decoder (struct cached_image *cimg)
{
#ifdef HAVE_JPEG
	struct jpg_decoder *jd;
#endif /* #ifdef HAVE_JPEG */
	struct png_decoder *pd;
#ifdef HAVE_TIFF
	struct tiff_decoder *td;
#endif /* #ifdef HAVE_TIFF */

	if (cimg->decoder){
		switch(cimg->image_type){
		case IM_PNG:
			pd=(struct png_decoder *)cimg->decoder;
			png_destroy_read_struct(
				&pd->png_ptr,
				&pd->info_ptr,
				NULL);
			break;
#ifdef HAVE_JPEG
		case IM_JPG:
			jd=(struct jpg_decoder *)cimg->decoder;

			jpeg_destroy_decompress(jd->cinfo);
			mem_free(jd->cinfo);
			mem_free(jd->jerr);
			if (jd->jdata) mem_free(jd->jdata);
			break;
#endif /* #ifdef HAVE_JPEG */
		case IM_GIF:
			gif_destroy_decoder(cimg);
			break;
		case IM_XBM:
			/* do nothing */
			break;
#ifdef HAVE_TIFF
		case IM_TIFF:
			td=(struct tiff_decoder *)cimg->decoder;
			if (td->tiff_open)
			{
				if (td->tiff_data)mem_free(td->tiff_data);
				td->tiff_open=0;
			}
			break;
#endif
		}
		mem_free(cimg->decoder);
	}
}

void img_destruct_image(struct g_object *object)
{
	struct g_object_image *goi=(struct g_object_image *)object;
	
	if (goi->orig_src)mem_free(goi->orig_src);
	if (goi->alt)mem_free(goi->alt);
	if (goi->name)mem_free(goi->name);
	if (goi->src)mem_free(goi->src);
	release_image_map(goi->map);
	if (goi->image_list.next)del_from_list(&goi->image_list);
	if (goi->xw&&goi->yw){
		 /* At least one dimension is zero */
		goi->cimg->refcount--;
	}
	mem_free(goi);
}

/* Frees all data allocated by cached_image including cached image itself */
void img_destruct_cached_image(struct cached_image *cimg)
{
	switch (cimg->state){
		case 0:
		case 1:
		case 2:
		case 3:
		case 9:
		case 11:
		break;
		
		case 12:
		case 14:
		if (cimg->gamma_table) mem_free(cimg->gamma_table);
		if (cimg->bmp.user){
			drv->unregister_bitmap(&(cimg->bmp));
		}
		if (cimg->strip_optimized){
			if (cimg->dregs) mem_free(cimg->dregs);
		}else{
			mem_free(cimg->buffer);
		}
		case 8:
		case 10:
		destroy_decoder(cimg);
		break;

		case 13:
		case 15:
		drv->unregister_bitmap(&(cimg->bmp));
		break;
		
#ifdef DEBUG
		default:
		fprintf(stderr,"img_destruct_cached_image: state=%d\n",cimg->state);
		internal("Invalid state in struct cached_image");
#endif /* #ifdef DEBUG */
	}
	mem_free(cimg->url);
	mem_free(cimg);
}

/* You throw in a vertical dimension of image and it returns
 * new dimension according to the aspect ratio and user-set image
 * scaling factor. When scaling factor is 100% and screen pixels
 * are non-square, the picture will be always in one dimension
 * untouched and in the second _ENLARGED_. So that no information
 * in the picture will be lost.
 * Input may be <0. In this case output=input
 * Input may be 0. In this case output=0.
 * If input is >0 the output is also >0.
 */
int img_scale_h(unsigned scale, int in){
	int out;
	/* We assume unsigned long holds at least 32 bits */
	unsigned long pre;

	if (in<=0) return in;
	pre=((unsigned long)(aspect<65536UL?65536UL:aspect)*scale+128)>>8;
	out=((unsigned long)in*pre+12800UL)/25600UL;
	if (out<1) out=1;
	return out;
}

int img_scale_v(unsigned scale, int in){
	int out;
	unsigned long divisor;

	if (in<=0) return in;
	divisor=(100*(aspect>=65536UL?65536UL:aspect)+128)>>8;
	out=((unsigned long)in*(scale*256)+(divisor>>1))/divisor;
	if (out<1) out=1;
	return out;
}

/* Returns height (pixels) for prescribed width (pixels). Honours aspect. */
static int width2height(float width_px, float width_mm, float height_mm)
{
	int height_px;

	if (width_px<=0) return width_px;
	height_px=(height_mm*width_px*65536)/(aspect*width_mm);
	if (height_px<1) height_px=1;
	return height_px;

}

/* Returns width (pixels) for prescribed height (pixels). Honours aspect. */
static int height2width(float height_px, float width_mm, float height_mm)
{
	int width_px;

	if (height_px<=0) return height_px;
	width_px=(width_mm*height_px*aspect)/(65536*height_mm);
	if (width_px<1) width_px=1;
	return width_px;

}

/* Compute 8-bit background for filling buffer with cimg->*_gamma
 * (performs rounding) */
void compute_background_8(unsigned char *rgb, struct cached_image *cimg)
{
	unsigned short red, green, blue;

	round_color_sRGB_to_48(&red, &green, &blue
		, cimg->background_color);
	rgb[0]=apply_gamma_single_16_to_8(red
		,cimg->red_gamma/user_gamma);
	rgb[1]=apply_gamma_single_16_to_8(green
		,cimg->green_gamma/user_gamma);
	rgb[2]=apply_gamma_single_16_to_8(blue
		,cimg->blue_gamma/user_gamma);
}

/* updates cimg state when header dimensions are know. Only allowed to be called
 * in state 8 and 10.
 * Allocates right amount of memory into buffer, formats it (with background or
 * zeroes, depens on buffer_bytes_per_pixel). Updates dimensions (xww and yww)
 * according to newly known header dimensions. Fills in gamma_stamp, bmp.user
 * (NULL because we not bother with generating bitmap here)
 * and rows_added.
 * Resets strip_optimized if image will be scaled or 
 * Allocates dregs if on exit strip_optimized is nonzero.
 * Allocates and computes gamma_table, otherwise
 * 	sets gamma_table to NULL. Also doesn't make gamma table if image contains less
 * 	than 1024 pixels (it would be probably a waste of time).
 * Output state is always 12 (from input state 8) or 14 (from input state 10).
 *
 * The caller must have set the following elements of cimg:
 *	width
 *	height
 *	buffer_bytes_per_pixel
 *	red_gamma
 *	green_gamma
 *	blue_gamma
 *	strip_optimized
 */
void header_dimensions_known(struct cached_image *cimg)
{
	unsigned short red, green, blue;

#ifdef DEBUG
	if ((cimg->state^8)&13){
		fprintf(stderr,"cimg->state=%d\n",cimg->state);
		internal("Invalid state in header_dimensions_known");
	}
	if (cimg->width<1||cimg->height<1){
		fprintf(stderr,"width=%d height=%d\n",cimg->width, cimg->height);
		internal("Zero dimensions in header_dimensions_known");
	}
#endif /* #ifdef DEBUG */
	if (cimg->wanted_xw<0){
		/* Unspecified width */
		if (cimg->wanted_yw<0){
			/* Unspecified neither width nor height */
			cimg->xww=img_scale_h(cimg->scale, cimg->width);
			cimg->yww=img_scale_v(cimg->scale, cimg->height);
		}else{
			/* Unspecified width specified height */
			cimg->xww=height2width(cimg->yww,
					cimg->width, cimg->height);
			if (cimg->xww<=0) cimg->xww=1;
			
		}
	}else{
		/* Specified width */
		if (cimg->wanted_yw<0){
			/* Unspecified height, specified width */
			cimg->yww=width2height(cimg->xww,
					cimg->width, cimg->height);
			if (cimg->yww<=0) cimg->yww=1;
		}else if (cimg->wanted_xyw_meaning==MEANING_AUTOSCALE){
			/* Specified height and width and autoscale meant */
			/* Try first to nail the height */
			cimg->yww=cimg->wanted_yw;
			cimg->xww=height2width(cimg->yww,
					cimg->width, cimg->height);
			if (cimg->xww>cimg->wanted_xw)
			{
				/* Width too much, we nail the width */
				cimg->xww=cimg->wanted_xw;
				cimg->yww=width2height(cimg->xww,
						cimg->width, cimg->height);
			}
			
			/* Some sanity checks */
			if (cimg->xww<=0) cimg->xww=1;
			if (cimg->yww<=0) cimg->yww=1;
		}
	}
	if (!is_image_size_sane(cimg->xww, cimg->yww)) {
		cimg->xww = cimg->width;
		cimg->yww = cimg->height;
	}
	if (cimg->width!=cimg->xww||cimg->height!=cimg->yww) cimg->strip_optimized=0;
	cimg->gamma_stamp=gamma_stamp;
	if (cimg->strip_optimized){
		struct bitmap tmpbmp;
		unsigned short *buf_16;
		int i;

		tmpbmp.x=cimg->width;
		tmpbmp.y=1;
		/* No buffer, bitmap is valid from the very beginning */
		cimg->bmp.x=cimg->width;
		cimg->bmp.y=cimg->height;
		drv->get_empty_bitmap(&(cimg->bmp));
		if ((unsigned)cimg->width > MAXINT / sizeof(*buf_16) / 3) overalloc();
		buf_16=mem_alloc(sizeof(*buf_16)*3*cimg->width);
		round_color_sRGB_to_48(&red, &green, &blue
			, cimg->background_color);
		mix_one_color_48(buf_16,cimg->width, red, green, blue);
#ifdef DEBUG
		if (cimg->height<=0){
			fprintf(stderr,"cimg->height=%d\n",cimg->height);
			internal("Invalid cimg->height in strip_optimized section of\
 header_dimensions_known");
		}
#endif /* #ifdef DEBUG */
		/* The skip is uninitialized here and is read by dither_start
		 * but is not used in any malicious way so it doesn't matter
		 */
		tmpbmp.data=cimg->bmp.data;
		cimg->dregs=dither_images?dither_start(buf_16,&tmpbmp):NULL;
		tmpbmp.data=(unsigned char *)tmpbmp.data+cimg->bmp.skip;
		if (cimg->dregs)
			for (i=cimg->height-1;i;i--){
				dither_restart(buf_16,&tmpbmp,cimg->dregs);
				tmpbmp.data=(unsigned char *)tmpbmp.data+cimg->bmp.skip;
			}
		else
			for (i=cimg->height-1;i;i--){
				(*round_fn)(buf_16,&tmpbmp);
				tmpbmp.data=(unsigned char *)tmpbmp.data+cimg->bmp.skip;
			}
		mem_free(buf_16);
		drv->register_bitmap(&(cimg->bmp));
		if(cimg->dregs) memset(cimg->dregs,0,cimg->width*sizeof(*cimg->dregs)*3);
		cimg->bmp.user=(void *)&end_callback_hit; /* Nonzero value */
		/* This ensures the dregs are none and because strip
		 * optimization is unusable in interlaced pictures,
		 * this saves the zeroing out at the beginning of the
		 * decoder itself.
		 */
	}else {
		cimg->rows_added=1;
		cimg->bmp.user=NULL;
		if (cimg->width && (unsigned)cimg->width * (unsigned)cimg->height / (unsigned)cimg->width != (unsigned)cimg->height) overalloc();
		if ((unsigned)cimg->width * (unsigned)cimg->height > (unsigned)MAXINT / cimg->buffer_bytes_per_pixel) overalloc();
		cimg->buffer=mem_alloc(cimg->width*cimg->height
			*cimg->buffer_bytes_per_pixel);
		if (cimg->buffer_bytes_per_pixel==4
			 	||cimg->buffer_bytes_per_pixel==4
				*sizeof(unsigned short))
			{	
			/* Make the buffer contain full transparency */
			memset(cimg->buffer,0,cimg->width*cimg->height
				*cimg->buffer_bytes_per_pixel);
		}else{
			/* Fill the buffer with background color */
			if (cimg->buffer_bytes_per_pixel>4){
				/* 16-bit */
				unsigned short red, green, blue;

				round_color_sRGB_to_48(&red, &green, &blue
					, cimg->background_color);

				red=apply_gamma_single_16_to_16(red
					,cimg->red_gamma/user_gamma);
				green=apply_gamma_single_16_to_16(green
					,cimg->green_gamma/user_gamma);
				blue=apply_gamma_single_16_to_16(blue
					,cimg->blue_gamma / user_gamma);
				mix_one_color_48((unsigned short *)cimg->buffer
					,cimg->width*cimg->height,red
					,green, blue);
			}else{
				unsigned char rgb[3];
				
				/* 8-bit */
				compute_background_8(rgb,cimg);
				mix_one_color_24(cimg->buffer
					,cimg->width*cimg->height
					,rgb[0],rgb[1],rgb[2]);
			}
		}
	}
	if (cimg->buffer_bytes_per_pixel<=4&&cimg->width*cimg->height>=1024){
		make_gamma_table(cimg);
	}else if (cimg->buffer_bytes_per_pixel>=6&&cimg->width*cimg->height>=262144){
		make_gamma_table(cimg);
	}else cimg->gamma_table=NULL;
	cimg->state|=4; /* Update state */
}

/* Fills "tmp" buffer with the resulting data and does not free the input
 * buffer. May be called only in states 12 and 14 of cimg
 */
unsigned short *buffer_to_16(unsigned short *tmp, struct cached_image *cimg
	,unsigned char *buffer, int height)
{
	unsigned short red, green,blue;