dip.c

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	}else{
		if (x && (unsigned)x * (unsigned)oy / (unsigned)x != (unsigned)oy) overalloc();
		if ((unsigned)x * (unsigned)oy > MAXINT) overalloc();
		outptr=mem_alloc(oy*x);
		inptr=in;
		*out=outptr;
		total=(iy-1)*(oy-1);
		if ((unsigned)x > MAXINT / sizeof(*row_buf)) overalloc();
		row_buf=mem_alloc(x*sizeof(*row_buf));
		bias_buf_gray(row_buf, x, half);
		out_pos=0;
		in_pos=0;
		again:
		in_begin=in_pos;
		in_end=in_pos+oy-1;
		add_row_gray(row_buf, inptr, x, in_end-out_pos);
		add_row_gray(row_buf, inptr+x, x, out_pos-in_begin);
		emit_and_bias_row_gray(row_buf, outptr, x, oy-1);
		outptr+=x;
		out_pos+=iy-1;
		if (out_pos>in_end){
			in_pos=in_end;
			inptr+=x;
		}
		if (out_pos>total){
			mem_free(in);
			mem_free(row_buf);
			return;
		}
		goto again;
	}	
}

/* For magnification only. Does linear filtering */
/* We assume unsigned holds at least 32 bits */
inline static void enlarge_color_vertical(unsigned short *ina, int x, int iy,
	unsigned short **outa ,int oy)
{
	unsigned *row_buf;
	int total,out_pos,in_pos,in_begin,in_end;
	int half=(oy-1)>>1;
	unsigned short *out, *in;

	if (iy==oy){
		*outa=ina;
		return;
	}
	/* Rivendell */
	if (x && (unsigned)x * (unsigned)oy / (unsigned)x != (unsigned)oy) overalloc();
	if ((unsigned)x * (unsigned)oy > MAXINT / 3 / sizeof(*out)) overalloc();
	out=mem_alloc(sizeof(*out)*3*oy*x);
	*outa=out;
	in=ina;
	if (iy==1){
		for (;oy;oy--){
	       		memcpy(out,in,3*x*sizeof(*out));
	       		out+=3*x;
		}
		mem_free(ina);
		return;
	}
	total=(iy-1)*(oy-1);
	if ((unsigned)x > MAXINT / 3 / sizeof(*row_buf)) overalloc();
	row_buf=mem_alloc(x*3*sizeof(*row_buf));
	bias_buf_color(row_buf,x,half);
	out_pos=0;
	in_pos=0;
	again:
	in_begin=in_pos;
	in_end=in_pos+oy-1;
	add_row_color(row_buf,in,x
		,in_end-out_pos);
	add_row_color(row_buf,in+3*x,x
		,out_pos-in_begin);
	emit_and_bias_row_color(row_buf,out,x,oy-1);
	out+=3*x;
	out_pos+=iy-1;
	if (out_pos>in_end){
		in_pos=in_end;
		in+=3*x;
	}
	if (out_pos>total){
		mem_free(ina);
		mem_free(row_buf);
		return;
	}
	goto again;
	
}	

/* Both enlarges and diminishes. Linear filtering.
 * Automatically allocates output and frees input.
 * We assume unsigned holds at least 32 bits */
inline static void scale_gray_vertical(unsigned char *in, int x, int iy,
	unsigned char ** out ,int oy)
{
	unsigned *row_buf;
	int total=iy*oy;
	int out_pos,in_pos,in_begin,in_end,out_end;
	unsigned char *outptr;
	unsigned char *inptr;

	/* Snow White, Snow White... */
	if (iy<oy){
		enlarge_gray_vertical(in,x,iy,out,oy);
		return;
	}
	if (iy==oy){
		*out=in;
		return;
	}
	if (x && (unsigned)x * (unsigned)oy / (unsigned)x != (unsigned)oy) overalloc();
	if ((unsigned)x * (unsigned)oy > MAXINT) overalloc();
	outptr=mem_alloc(x*oy);
	inptr=in;
	*out=outptr;
	if ((unsigned)x > MAXINT / sizeof(*row_buf)) overalloc();
	row_buf=mem_calloc(x*sizeof(*row_buf));
	bias_buf_gray(row_buf, x, iy>>1);
	out_pos=0;
	in_pos=0;
	again:
	in_begin=in_pos;
	in_end=in_pos+oy;
	out_end=out_pos+iy;
	if (in_begin<out_pos)in_begin=out_pos;
	if (in_end>out_end)in_end=out_end;
	add_row_gray(row_buf,inptr,x,in_end-in_begin);
	in_end=in_pos+oy;
	if (out_end>=in_end){
		in_pos=in_end;
		inptr+=x;
	}
	if (out_end<=in_end){
			emit_and_bias_row_gray(row_buf,outptr,x,iy);
			out_pos=out_pos+iy;
			outptr+=x;
	}
	if (out_pos==total){
		mem_free(in);
		mem_free(row_buf);
		return;
	}
	goto again;
}

/* Both enlarges and diminishes. Linear filtering. Sizes are
   in pixels. Sizes are not in bytes. 1 pixel=3 unsigned shorts.
   We assume unsigned short can hold at least 16 bits.
   We assume unsigned holds at least 32 bits.
 */
inline static void scale_color_vertical(unsigned short *ina, int x, int iy
	,unsigned short **outa, int oy)
{
	unsigned *row_buf;
	int total=iy*oy;
	int out_pos,in_pos,in_begin,in_end,out_end;
	unsigned short *in, *out;

	if (iy==oy){
		*outa=ina;
		return;
	}
	if (iy<oy){
		enlarge_color_vertical(ina,x,iy,outa,oy);
		return;
	}
	if (x && (unsigned)x * (unsigned)oy / (unsigned)x != (unsigned)oy) overalloc();
	if ((unsigned)x * (unsigned)oy > MAXINT / 3 / sizeof(*out)) overalloc();
	out=mem_alloc(sizeof(*out)*3*oy*x);
	*outa=out;
	in=ina;
	if ((unsigned)x > MAXINT / 3 / sizeof(*row_buf)) overalloc();
	row_buf=mem_alloc(x*3*sizeof(*row_buf));
	bias_buf_color(row_buf,x,iy>>1);
	out_pos=0;
	in_pos=0;
	again:
	in_begin=in_pos;
	in_end=in_pos+oy;
	out_end=out_pos+iy;
	if (in_begin<out_pos)in_begin=out_pos;
	if (in_end>out_end)in_end=out_end;
	add_row_color(row_buf,in,x,in_end-in_begin);
	in_end=in_pos+oy;
	if (out_end>=in_end){
		in_pos=in_end;
		in+=3*x;
	}
	if (out_end<=in_end){
			emit_and_bias_row_color(row_buf,out,x,iy);
			out_pos=out_pos+iy;
			out+=3*x;
	}
	if (out_pos==total){
		mem_free(ina);
		mem_free(row_buf);
		return;
	}
	goto again;
}


/* Scales grayscale 8-bit map. Both enlarges and diminishes. Uses either low
 * pass or bilinear filtering. Automatically mem_frees the "in".
 * Automatically allocates "out".
 */
inline static void scale_gray(unsigned char *in, int ix, int iy, unsigned char **out
	,int ox, int oy)
{
	unsigned char *intermediate_buffer;

	if (!ix||!iy){
		if (in) mem_free(in);
		if (ox && (unsigned)ox * (unsigned)oy / (unsigned)ox != (unsigned)oy) overalloc();
		if ((unsigned)ox * (unsigned)oy > MAXINT) overalloc();
		*out=mem_calloc(ox*oy);
		return;
	}
	if (ix*oy<ox*iy){
		scale_gray_vertical(in,ix,iy,&intermediate_buffer,oy);
		scale_gray_horizontal(intermediate_buffer,ix,oy,out,ox);
	}else{
		scale_gray_horizontal(in,ix,iy,&intermediate_buffer,ox);
		scale_gray_vertical(intermediate_buffer,ox,iy,out,oy);
	}
}

/* To be called only when global variable display_optimize is 1 or 2.
 * Performs a decimation according to this variable. Data shrink to 1/3
 * and x is the smaller width.
 * There must be 9*x*y unsigned shorts of data.
 * x must be >=1.
 * Performs realloc onto the buffer after decimation to save memory.
 */
void decimate_3(unsigned short **data0, int x, int y)
{
	unsigned short *data=*data0;
	unsigned short *ahead=data;
	int i, futuresize;
	if (x && (unsigned)x * (unsigned)y / (unsigned)x != (unsigned)y) overalloc();
	if ((unsigned)x * (unsigned)y > MAXINT / 3 / sizeof(**data0)) overalloc();
	futuresize=x*y*3*sizeof(**data0);
	
#ifdef DEBUG
	if (!(x>0&&y>0)) internal("zero width or height in decimate_3");
#endif /* #Ifdef DEBUG */
	if (display_optimize==1){
		if (x==1){
			for (;y;y--,ahead+=9,data+=3){
				data[0]=(ahead[0]+ahead[0]+ahead[3])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[5]+ahead[8]+ahead[8])/3;
			}
		}else{
			for (;y;y--){
				data[0]=(ahead[0]+ahead[0]+ahead[3])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[5]+ahead[8]+ahead[11])/3;
				for (ahead+=9,data+=3,i=x-2;i;i--,ahead+=9,data+=3){
					data[0]=(ahead[-3]+ahead[0]+ahead[3])/3;
					data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
					data[2]=(ahead[5]+ahead[8]+ahead[11])/3;
				}
				data[0]=(ahead[-3]+ahead[0]+ahead[3])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[5]+ahead[8]+ahead[8])/3;
				ahead+=9,data+=3;
			}
		}
	}else{
		/* display_optimize==2 */
		if (x==1){
			for (;y;y--,ahead+=9,data+=3){
				data[0]=(ahead[3]+ahead[6]+ahead[6])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[2]+ahead[2]+ahead[5])/3;
			}
		}else{
			for (;y;y--){
				data[0]=(ahead[3]+ahead[6]+ahead[9])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[2]+ahead[2]+ahead[5])/3;
				for (ahead+=9,data+=3,i=x-2;i;i--,ahead+=9,data+=3){
					data[0]=(ahead[3]+ahead[6]+ahead[9])/3;
					data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
					data[2]=(ahead[-1]+ahead[2]+ahead[5])/3;
				}
				data[0]=(ahead[3]+ahead[6]+ahead[6])/3;
				data[1]=(ahead[1]+ahead[4]+ahead[7])/3;
				data[2]=(ahead[-1]+ahead[2]+ahead[5])/3;
				ahead+=9,data+=3;
			}
		}
	}	
	*data0=mem_realloc(*data0,futuresize);
}

/* Scales color 48-bits-per-pixel bitmap. Both enlarges and diminishes. Uses
 * either low pass or bilinear filtering. The memory organization for both
 * input and output are red, green, blue. All three of them are unsigned shorts 0-65535.
 * Allocates output and frees input
 * We assume unsigned short holds at least 16 bits.
 */
void scale_color(unsigned short *in, int ix, int iy, unsigned short **out,
	int ox, int oy)
{
	unsigned short *intermediate_buffer;
	int do_optimize;
	int ox0=ox;

	if (!ix||!iy){
		if (in) mem_free(in);
		if (ox && (unsigned)ox * (unsigned)oy / (unsigned)ox != (unsigned)oy) overalloc();
		if ((unsigned)ox * (unsigned)oy > MAXINT / 3 / sizeof(**out)) overalloc();
		*out=mem_calloc(ox*oy*sizeof(**out)*3);
		return;
	}
	if (display_optimize&&ox*3<=ix){
		do_optimize=1;
		ox0=ox;
		ox*=3;
	}else do_optimize=0;
	if (ix*oy<ox*iy){
		scale_color_vertical(in,ix,iy,&intermediate_buffer,oy);
		scale_color_horizontal(intermediate_buffer,ix,oy,out,ox);
	}else{
		scale_color_horizontal(in,ix,iy,&intermediate_buffer,ox);
		scale_color_vertical(intermediate_buffer,ox,iy,out,oy);
	}
	if (do_optimize) decimate_3(out, ox0, oy);
}

/* Fills a block with given color. length is number of pixels. pixel is a
 * tribyte. 24 bits per pixel.
 */
void mix_one_color_24(unsigned char *dest, int length,
		   unsigned char r, unsigned char g, unsigned char b)
{
	for (;length;length--){
		dest[0]=r;
		dest[1]=g;
		dest[2]=b;
		dest+=3;
	}
}

/* Fills a block with given color. length is number of pixels. pixel is a
 * tribyte. 48 bits per pixel.
 * We assume unsigned short holds at least 16 bits.
 */
void mix_one_color_48(unsigned short *dest, int length,
		   unsigned short r, unsigned short g, unsigned short b)
{
	for (;length;length--){
		dest[0]=r;
		dest[1]=g;
		dest[2]=b;
		dest+=3;
	}
}

/* Mixes ink and paper of a letter, using alpha as alpha mask.
 * Only mixing in photon space makes physical sense so that the input values
 * must always be equivalent to photons and not to electrons!
 * length is number of pixels. pixel is a tribyte
 * alpha is 8-bit, rgb are all 16-bit
 * We assume unsigned short holds at least 16 bits.
 */
inline static void mix_two_colors(unsigned short *dest, unsigned char *alpha, int length
	,unsigned short r0, unsigned short g0, unsigned short b0,
	unsigned short r255, unsigned short g255, unsigned short b255)
{
	unsigned mask,cmask;
	
	for (;length;length--){
		mask=*alpha++;
		if (((unsigned char)(mask+1))>=2){
			cmask=255-mask;
			dest[0]=(mask*r255+cmask*r0+127)/255;
			dest[1]=(mask*g255+cmask*g0+127)/255;
			dest[2]=(mask*b255+cmask*b0+127)/255;
		}else{
			if (mask){
				dest[0]=r255;
				dest[1]=g255;
				dest[2]=b255;
			}else{
				dest[0]=r0;
				dest[1]=g0;
				dest[2]=b0;
			}
		}
		dest+=3;
	}
}

/* We assume unsigned short holds at least 16 bits. */
void apply_gamma_exponent_and_undercolor_32_to_48_table(unsigned short *dest,
		unsigned char *src, int lenght, unsigned short *table
		,unsigned short rb, unsigned short gb, unsigned short bb)
{
	unsigned alpha, ri, gi, bi, calpha;

	for (;lenght;lenght--)
	{
		ri=table[src[0]];
		gi=table[src[1]+256];
		bi=table[src[2]+512];
		alpha=src[3];
		src+=4;
		if (((unsigned char)(alpha+1))>=2){
			calpha=255U-alpha;
			dest[0]=(ri*alpha+calpha*rb+127)/255;
			dest[1]=(gi*alpha+calpha*gb+127)/255;
			dest[2]=(bi*alpha+calpha*bb+127)/255;
		}else{
			if (alpha){
				dest[0]=ri;
				dest[1]=gi;
				dest[2]=bi;
			}else{
				dest[0]=rb;
				dest[1]=gb;
				dest[2]=bb;
			}
		}
		dest+=3;
	}
}

/* src is a block of four-bytes RGBA. All bytes are gamma corrected. length is
 * number of pixels. output is input powered to the given gamma, passed into
 * dest. src and dest may be identical and it will work. rb, gb, bb are 0-65535
 * in linear monitor output photon space
 */
/* We assume unsigned short holds at least 16 bits. */
void apply_gamma_exponent_and_undercolor_32_to_48(unsigned short *dest,
		unsigned char *src, int lenght, float red_gamma
		,float green_gamma, float blue_gamma, unsigned short rb, unsigned
		short gb, unsigned short bb)
{
	float r,g,b;
	unsigned alpha, calpha;
	unsigned ri,gi,bi;
	const float inv_255=1/255.0;

	for (;lenght;lenght--)
	{
		r=src[0];
		g=src[1];
		b=src[2];
		alpha=src[3];
		src+=4;
		r*=inv_255;
		g*=inv_255;
		b*=inv_255;
		r=pow(r,red_gamma);
		g=pow(g,green_gamma);
		b=pow(b,blue_gamma);
		ri=(r*65535)+0.5;
		gi=(g*65535)+0.5;
		bi=(b*65535)+0.5;
#if SIZEOF_UNSIGNED_SHORT > 2
		/* To prevent segfaults in case of crappy floating arithmetics
		 */
		if (ri>=65536) ri=65535;
		if (gi>=65536) gi=65535;
		if (bi>=65536) bi=65535;
#endif /* #if SIZEOF_UNSIGNED_SHORT > 2 */
		if (((alpha+1U)&0xffU)>=2U){
			calpha=255U-alpha;
			*dest=(ri*alpha+calpha*rb+127U)/255U;
			dest[1]=(gi*alpha+calpha*gb+127U)/255U;
			dest[2]=(bi*alpha+calpha*bb+127U)/255U;
		}else{
			if (alpha){
				*dest=ri;
				dest[1]=gi;
				dest[2]=bi;
			}else{
				*dest=rb;
				dest[1]=gb;
				dest[2]=bb;
			}
		}
		dest+=3;
	}
}

/* src is a block of four-bytes RGBA. All bytes are gamma corrected. length is
 * number of pixels. output is input powered to the given gamma, passed into
 * dest. src and dest may be identical and it will work. rb, gb, bb are 0-65535
 * in linear monitor output photon space. alpha 255 means full image no background.
 */
/* We assume unsigned short holds at least 16 bits. */
void apply_gamma_exponent_and_undercolor_64_to_48(unsigned short *dest,
		unsigned short *src, int lenght, float red_gamma
		,float green_gamma, float blue_gamma, unsigned short rb, unsigned
		short gb, unsigned short bb)
{
	float r,g,b;
	unsigned alpha, calpha;
	unsigned short ri,gi,bi;
	const float inv_65535=1/((float)65535);

	for (;lenght;lenght--)
	{
		r=src[0];
		g=src[1];
		b=src[2];
		alpha=src[3];
		src+=4;
		r*=inv_65535;
		g*=inv_65535;
		b*=inv_65535;
		r=pow(r,red_gamma);
		g=pow(g,green_gamma);
		b=pow(b,blue_gamma);
		ri=r*65535+0.5;
		gi=g*65535+0.5;
		bi=b*65535+0.5;
#if SIZEOF_UNSIGNED_SHORT > 2
		/* To prevent segfaults in case of crappy floating arithmetics
		 */
		if (ri>=65536) ri=65535;
		if (gi>=65536) gi=65535;
		if (bi>=65536) bi=65535;
#endif /* #if SIZEOF_UNSIGNED_SHORT > 2 */
		if (((alpha+1U)&255U)>=2U){
			calpha=65535U-alpha;
			*dest=(ri*alpha+calpha*rb+32767U)/65535U;
			dest[1]=(gi*alpha+calpha*gb+32767U)/65535U;
			dest[2]=(bi*alpha+calpha*bb+32767U)/65535U;
		}else{
			if (alpha){
				*dest=ri;
				dest[1]=gi;
				dest[2]=bi;
			}else{