#include <fitz.h>

typedef unsigned char byte;

/*
 * Blend pixmap regions
 */

/* dst = src over dst */
static void
duff_non(byte *sp0, int sw, int sn, byte *dp0, int dw, int w0, int h)
{
	int k;
	while (h--)
	{
		byte *sp = sp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte sa = sp[0];
			byte ssa = 255 - sa;
			for (k = 0; k < sn; k++)
			{
				dp[k] = sp[k] + fz_mul255(dp[k], ssa);
			}
			sp += sn;
			dp += sn;
		}
		sp0 += sw;
		dp0 += dw;
	}
}

/* dst = src in msk */
static void
duff_nimcn(byte *sp0, int sw, int sn, byte *mp0, int mw, int mn, byte *dp0, int dw, int w0, int h)
{
	int k;
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte ma = mp[0];
			for (k = 0; k < sn; k++)
				dp[k] = fz_mul255(sp[k], ma);
			sp += sn;
			mp += mn;
			dp += sn;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

/* dst = src in msk over dst */
static void
duff_nimon(byte *sp0, int sw, int sn, byte *mp0, int mw, int mn, byte *dp0, int dw, int w0, int h)
{
	int k;
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			/* TODO: validate this */
			byte ma = mp[0];
			byte sa = fz_mul255(sp[0], ma);
			byte ssa = 255 - sa;
			for (k = 0; k < sn; k++)
			{
				dp[k] = fz_mul255(sp[k], ma) + fz_mul255(dp[k], ssa);
			}
			sp += sn;
			mp += mn;
			dp += sn;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

static void duff_1o1(byte *sp0, int sw, byte *dp0, int dw, int w0, int h)
{
	/* duff_non(sp0, sw, 1, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			dp[0] = sp[0] + fz_mul255(dp[0], 255 - sp[0]);
			sp ++;
			dp ++;
		}
		sp0 += sw;
		dp0 += dw;
	}
}

static void duff_4o4(byte *sp0, int sw, byte *dp0, int dw, int w0, int h)
{
	/* duff_non(sp0, sw, 4, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte ssa = 255 - sp[0];
			dp[0] = sp[0] + fz_mul255(dp[0], ssa);
			dp[1] = sp[1] + fz_mul255(dp[1], ssa);
			dp[2] = sp[2] + fz_mul255(dp[2], ssa);
			dp[3] = sp[3] + fz_mul255(dp[3], ssa);
			sp += 4;
			dp += 4;
		}
		sp0 += sw;
		dp0 += dw;
	}
}

static void duff_1i1c1(byte *sp0, int sw, byte *mp0, int mw, byte *dp0, int dw, int w0, int h)
{
	/* duff_nimcn(sp0, sw, 1, mp0, mw, 1, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			dp[0] = fz_mul255(sp[0], mp[0]);
			sp ++;
			mp ++;
			dp ++;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

static void duff_4i1c4(byte *sp0, int sw, byte *mp0, int mw, byte *dp0, int dw, int w0, int h)
{
	/* duff_nimcn(sp0, sw, 4, mp0, mw, 1, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte ma = mp[0];
			dp[0] = fz_mul255(sp[0], ma);
			dp[1] = fz_mul255(sp[1], ma);
			dp[2] = fz_mul255(sp[2], ma);
			dp[3] = fz_mul255(sp[3], ma);
			sp += 4;
			mp += 1;
			dp += 4;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

static void duff_1i1o1(byte *sp0, int sw, byte *mp0, int mw, byte *dp0, int dw, int w0, int h)
{
	/* duff_nimon(sp0, sw, 1, mp0, mw, 1, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte ma = mp[0];
			byte sa = fz_mul255(sp[0], ma);
			byte ssa = 255 - sa;
			dp[0] = fz_mul255(sp[0], ma) + fz_mul255(dp[0], ssa);
			sp ++;
			mp ++;
			dp ++;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

static void duff_4i1o4(byte *sp0, int sw, byte *mp0, int mw, byte *dp0, int dw, int w0, int h)
{
	/* duff_nimon(sp0, sw, 4, mp0, mw, 1, dp0, dw, w0, h); */
	while (h--)
	{
		byte *sp = sp0;
		byte *mp = mp0;
		byte *dp = dp0;
		int w = w0;
		while (w--)
		{
			byte ma = mp[0];
			byte sa = fz_mul255(sp[0], ma);
			byte ssa = 255 - sa;
			dp[0] = fz_mul255(sp[0], ma) + fz_mul255(dp[0], ssa);
			dp[1] = fz_mul255(sp[1], ma) + fz_mul255(dp[1], ssa);
			dp[2] = fz_mul255(sp[2], ma) + fz_mul255(dp[2], ssa);
			dp[3] = fz_mul255(sp[3], ma) + fz_mul255(dp[3], ssa);
			sp += 4;
			mp += 1;
			dp += 4;
		}
		sp0 += sw;
		mp0 += mw;
		dp0 += dw;
	}
}

/*
 * Path and text masks
 */

static void path_1c1(byte *src, byte *dst, int w)
{
	memcpy(dst, src, w);
}

static void path_1o1(byte *src, byte *dst, int w)
{
	while (w--)
	{
		dst[0] = src[0] + fz_mul255(dst[0], 255 - src[0]);
		src++;
		dst++;
	}
}

static void path_w3i1o4(byte *rgb, byte *src, byte *dst, int n)
{
	byte rgb0 = rgb[0];
	byte rgb1 = rgb[1];
	byte rgb2 = rgb[2];
	byte sa, ssa;
	while (n--)
	{
		sa = src[0];
		ssa = 255 - sa;
		dst[0] = sa + fz_mul255(dst[0], ssa);
		dst[1] = rgb0 + fz_mul255((short)dst[1] - rgb0, ssa);
		dst[2] = rgb1 + fz_mul255((short)dst[2] - rgb1, ssa);
		dst[3] = rgb2 + fz_mul255((short)dst[3] - rgb2, ssa);
		src ++;
		dst += 4;
	}
}

static void text_1c1(byte *src, int srcw, byte *dst, int dstw, int w0, int h)
{
	while (h--)
	{
		path_1c1(src, dst, w0);
		src += srcw;
		dst += dstw;
	}
}

static void text_1o1(byte *src, int srcw, byte *dst, int dstw, int w0, int h)
{
	while (h--)
	{
		path_1o1(src, dst, w0);
		src += srcw;
		dst += dstw;
	}
}

static void text_w3i1o4(byte *rgb, byte *src, int srcw, byte *dst, int dstw, int w0, int h)
{
	while (h--)
	{
		path_w3i1o4(rgb, src, dst, w0);
		src += srcw;
		dst += dstw;
	}
}

/*
 * ... and the function pointers
 */

void (*fz_duff_non)(byte*,int,int,byte*,int,int,int) = duff_non;
void (*fz_duff_nimcn)(byte*,int,int,byte*,int,int,byte*,int,int,int) = duff_nimcn;
void (*fz_duff_nimon)(byte*,int,int,byte*,int,int,byte*,int,int,int) = duff_nimon;
void (*fz_duff_1o1)(byte*,int,byte*,int,int,int) = duff_1o1;
void (*fz_duff_4o4)(byte*,int,byte*,int,int,int) = duff_4o4;
void (*fz_duff_1i1c1)(byte*,int,byte*,int,byte*,int,int,int) = duff_1i1c1;
void (*fz_duff_4i1c4)(byte*,int,byte*,int,byte*,int,int,int) = duff_4i1c4;
void (*fz_duff_1i1o1)(byte*,int,byte*,int,byte*,int,int,int) = duff_1i1o1;
void (*fz_duff_4i1o4)(byte*,int,byte*,int,byte*,int,int,int) = duff_4i1o4;

void (*fz_path_1c1)(byte*,byte*,int) = path_1c1;
void (*fz_path_1o1)(byte*,byte*,int) = path_1o1;
void (*fz_path_w3i1o4)(byte*,byte*,byte*,int) = path_w3i1o4;

void (*fz_text_1c1)(byte*,int,byte*,int,int,int) = text_1c1;
void (*fz_text_1o1)(byte*,int,byte*,int,int,int) = text_1o1;
void (*fz_text_w3i1o4)(byte*,byte*,int,byte*,int,int,int) = text_w3i1o4;