/* raster.c - main and other misc stuff
 *
 * Raster graphics library
 *
 * Copyright (c) 1997-2003 Alfredo K. Kojima
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *  MA 02110-1301, USA.
 */

#include <config.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include "wraster.h"

#include <assert.h>

char *WRasterLibVersion = "0.9";

int RErrorCode = RERR_NONE;

#define HAS_ALPHA(I)	((I)->format == RRGBAFormat)

#define MAX_WIDTH 20000
#define MAX_HEIGHT 20000
/* 20000^2*4 < 2G */

RImage *RCreateImage(unsigned width, unsigned height, int alpha)
{
	RImage *image = NULL;

	assert(width > 0 && height > 0);

	if (width > MAX_WIDTH || height > MAX_HEIGHT) {
		RErrorCode = RERR_NOMEMORY;
		return NULL;
	}

	image = malloc(sizeof(RImage));
	if (!image) {
		RErrorCode = RERR_NOMEMORY;
		return NULL;
	}

	memset(image, 0, sizeof(RImage));
	image->width = width;
	image->height = height;
	image->format = alpha ? RRGBAFormat : RRGBFormat;
	image->refCount = 1;

	/* the +4 is to give extra bytes at the end of the buffer,
	 * so that we can optimize image conversion for MMX(tm).. see convert.c
	 */
	image->data = malloc(width * height * (alpha ? 4 : 3) + 4);
	if (!image->data) {
		RErrorCode = RERR_NOMEMORY;
		free(image);
		image = NULL;
	}

	return image;

}

RImage *RRetainImage(RImage * image)
{
	if (image)
		image->refCount++;

	return image;
}

void RReleaseImage(RImage * image)
{
	assert(image != NULL);

	image->refCount--;

	if (image->refCount < 1) {
		free(image->data);
		free(image);
	}
}

RImage *RCloneImage(RImage * image)
{
	RImage *new_image;

	assert(image != NULL);

	new_image = RCreateImage(image->width, image->height, HAS_ALPHA(image));
	if (!new_image)
		return NULL;

	new_image->background = image->background;
	memcpy(new_image->data, image->data, image->width * image->height * (HAS_ALPHA(image) ? 4 : 3));

	return new_image;
}

RImage *RGetSubImage(RImage * image, int x, int y, unsigned width, unsigned height)
{
	int i, ofs;
	RImage *new_image;
	unsigned total_line_size, line_size;

	assert(image != NULL);
	assert(x >= 0 && y >= 0);
	assert(x < image->width && y < image->height);
	assert(width > 0 && height > 0);

	if (x + width > image->width)
		width = image->width - x;
	if (y + height > image->height)
		height = image->height - y;

	new_image = RCreateImage(width, height, HAS_ALPHA(image));

	if (!new_image)
		return NULL;
	new_image->background = image->background;

	total_line_size = image->width * (HAS_ALPHA(image) ? 4 : 3);
	line_size = width * (HAS_ALPHA(image) ? 4 : 3);

	ofs = x * (HAS_ALPHA(image) ? 4 : 3) + y * total_line_size;;

	for (i = 0; i < height; i++) {
		memcpy(&new_image->data[i * line_size], &image->data[i * total_line_size + ofs], line_size);
	}
	return new_image;
}

/*
 *----------------------------------------------------------------------
 * RCombineImages-
 * 	Combines two equal sized images with alpha image. The second
 * image will be placed on top of the first one.
 *----------------------------------------------------------------------
 */
void RCombineImages(RImage * image, RImage * src)
{
	assert(image->width == src->width);
	assert(image->height == src->height);

	if (!HAS_ALPHA(src)) {
		if (!HAS_ALPHA(image)) {
			memcpy(image->data, src->data, image->height * image->width * 3);
		} else {
			int x, y;
			unsigned char *d, *s;

			d = image->data;
			s = src->data;
			for (y = 0; y < image->height; y++) {
				for (x = 0; x < image->width; x++) {
					*d++ = *s++;
					*d++ = *s++;
					*d++ = *s++;
					*d++ = 255;
				}
			}
		}
	} else {
		register int i;
		unsigned char *d;
		unsigned char *s;
		int alpha, calpha;

		d = image->data;
		s = src->data;

		if (!HAS_ALPHA(image)) {
			for (i = 0; i < image->height * image->width; i++) {
				alpha = *(s + 3);
				calpha = 255 - alpha;
				*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
				d++;
				s++;
				*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
				d++;
				s++;
				*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
				d++;
				s++;
				s++;
			}
		} else {
			RCombineAlpha(d, s, 1, image->width, image->height, 0, 0, 255);
		}
	}
}

void RCombineImagesWithOpaqueness(RImage * image, RImage * src, int opaqueness)
{
	register int i;
	unsigned char *d;
	unsigned char *s;
	int c_opaqueness;

	assert(image->width == src->width);
	assert(image->height == src->height);

	d = image->data;
	s = src->data;

	c_opaqueness = 255 - opaqueness;

#define OP opaqueness
#define COP c_opaqueness

	if (!HAS_ALPHA(src)) {
		if (!HAS_ALPHA(image)) {
			for (i = 0; i < image->width * image->height; i++) {
				*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
				d++;
				s++;
				*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
				d++;
				s++;
				*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
				d++;
				s++;
			}
		} else {
			RCombineAlpha(d, s, 0, image->width, image->height, 0, 0, OP);
		}
	} else {
		int tmp;

		if (!HAS_ALPHA(image)) {
			for (i = 0; i < image->width * image->height; i++) {
				tmp = (*(s + 3) * opaqueness) / 256;
				*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
				d++;
				s++;
				*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
				d++;
				s++;
				*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
				d++;
				s++;
				s++;
			}
		} else {
			RCombineAlpha(d, s, 1, image->width, image->height, 0, 0, opaqueness);
		}
	}
#undef OP
#undef COP
}

static int calculateCombineArea(RImage *des, int *sx, int *sy, unsigned int *swidth,
				unsigned int *sheight, int *dx, int *dy)
{
	int width = (int)*swidth, height = (int)*sheight;

	if (*dx < 0) {
		*sx = -*dx;
		width = width + *dx;
		*dx = 0;
	}

	if (*dx + width > des->width) {
		width = des->width - *dx;
	}

	if (*dy < 0) {
		*sy = -*dy;
		height = height + *dy;
		*dy = 0;
	}

	if (*dy + height > des->height) {
		height = des->height - *dy;
	}

	if (height > 0 && width > 0) {
		*swidth = width;
		*sheight = height;
		return True;
	}

	return False;
}

void RCombineArea(RImage * image, RImage * src, int sx, int sy, unsigned width, unsigned height, int dx, int dy)
{
	int x, y, dwi, swi;
	unsigned char *d;
	unsigned char *s;
	int alpha, calpha;

	if (!calculateCombineArea(image, &sx, &sy, &width, &height, &dx, &dy))
		return;

	if (!HAS_ALPHA(src)) {
		if (!HAS_ALPHA(image)) {
			swi = src->width * 3;
			dwi = image->width * 3;

			s = src->data + (sy * (int)src->width + sx) * 3;
			d = image->data + (dy * (int)image->width + dx) * 3;

			for (y = 0; y < height; y++) {
				memcpy(d, s, width * 3);
				d += dwi;
				s += swi;
			}
		} else {
			swi = (src->width - width) * 3;
			dwi = (image->width - width) * 4;

			s = src->data + (sy * (int)src->width + sx) * 3;
			d = image->data + (dy * (int)image->width + dx) * 4;

			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					*d++ = *s++;
					*d++ = *s++;
					*d++ = *s++;
					*d++ = 255;
				}
				d += dwi;
				s += swi;
			}
		}
	} else {
		int dalpha = HAS_ALPHA(image);

		swi = (src->width - width) * 4;
		s = src->data + (sy * (int)src->width + sx) * 4;
		if (dalpha) {
			dwi = (image->width - width) * 4;
			d = image->data + (dy * (int)image->width + dx) * 4;
		} else {
			dwi = (image->width - width) * 3;
			d = image->data + (dy * (int)image->width + dx) * 3;
		}

		if (!dalpha) {
			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					alpha = *(s + 3);
					calpha = 255 - alpha;
					*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
					s++;
					d++;
					*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
					s++;
					d++;
					*d = (((int)*d * calpha) + ((int)*s * alpha)) / 256;
					s++;
					d++;
					s++;
				}
				d += dwi;
				s += swi;
			}
		} else {
			RCombineAlpha(d, s, 1, width, height, dwi, swi, 255);
		}
	}
}

void RCopyArea(RImage * image, RImage * src, int sx, int sy, unsigned width, unsigned height, int dx, int dy)
{
	int x, y, dwi, swi;
	unsigned char *d;
	unsigned char *s;

	if (!calculateCombineArea(image, &sx, &sy, &width, &height, &dx, &dy))
		return;

	if (!HAS_ALPHA(src)) {
		if (!HAS_ALPHA(image)) {
			swi = src->width * 3;
			dwi = image->width * 3;

			s = src->data + (sy * (int)src->width + sx) * 3;
			d = image->data + (dy * (int)image->width + dx) * 3;

			for (y = 0; y < height; y++) {
				memcpy(d, s, width * 3);
				d += dwi;
				s += swi;
			}
		} else {
			swi = (src->width - width) * 3;
			dwi = (image->width - width) * 4;

			s = src->data + (sy * (int)src->width + sx) * 3;
			d = image->data + (dy * (int)image->width + dx) * 4;

			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					*d++ = *s++;
					*d++ = *s++;
					*d++ = *s++;
					d++;
				}
				d += dwi;
				s += swi;
			}
		}
	} else {
		int dalpha = HAS_ALPHA(image);

		swi = src->width * 4;
		s = src->data + (sy * (int)src->width + sx) * 4;
		if (dalpha) {
			dwi = image->width * 4;
			d = image->data + (dy * (int)image->width + dx) * 4;
		} else {
			dwi = image->width * 3;
			d = image->data + (dy * (int)image->width + dx) * 3;
		}

		if (dalpha) {
			for (y = 0; y < height; y++) {
				memcpy(d, s, width * 4);
				d += dwi;
				s += swi;
			}
		} else {
			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					*d++ = *s++;
					*d++ = *s++;
					*d++ = *s++;
					s++;
				}
				d += dwi;
				s += swi;
			}
		}
	}
}

void
RCombineAreaWithOpaqueness(RImage * image, RImage * src, int sx, int sy,
			   unsigned width, unsigned height, int dx, int dy, int opaqueness)
{
	int x, y, dwi, swi;
	int c_opaqueness;
	unsigned char *s, *d;
	int dalpha = HAS_ALPHA(image);
	int dch = (dalpha ? 4 : 3);

	if (!calculateCombineArea(image, &sx, &sy, &width, &height, &dx, &dy))
		return;

	d = image->data + (dy * image->width + dx) * dch;
	dwi = (image->width - width) * dch;

	c_opaqueness = 255 - opaqueness;

#define OP opaqueness
#define COP c_opaqueness

	if (!HAS_ALPHA(src)) {

		s = src->data + (sy * src->width + sx) * 3;
		swi = (src->width - width) * 3;

		if (!dalpha) {
			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
					s++;
					d++;
					*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
					s++;
					d++;
					*d = (((int)*d * (int)COP) + ((int)*s * (int)OP)) / 256;
					s++;
					d++;
				}
				d += dwi;
				s += swi;
			}
		} else {
			RCombineAlpha(d, s, 0, width, height, dwi, swi, OP);
		}
	} else {
		int tmp;

		s = src->data + (sy * src->width + sx) * 4;
		swi = (src->width - width) * 4;

		if (!dalpha) {
			for (y = 0; y < height; y++) {
				for (x = 0; x < width; x++) {
					tmp = (*(s + 3) * opaqueness) / 256;
					*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
					d++;
					s++;
					*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
					d++;
					s++;
					*d = (((int)*d * (255 - tmp)) + ((int)*s * tmp)) / 256;
					d++;
					s++;
					s++;
				}
				d += dwi;
				s += swi;
			}
		} else {
			RCombineAlpha(d, s, 1, width, height, dwi, swi, OP);
		}
	}
#undef OP
#undef COP
}

void RCombineImageWithColor(RImage * image, RColor * color)
{
	register int i;
	unsigned char *d;
	int alpha, nalpha, r, g, b;

	d = image->data;

	if (!HAS_ALPHA(image)) {
		/* Image has no alpha channel, so we consider it to be all 255.
		 * Thus there are no transparent parts to be filled. */
		return;
	}
	r = color->red;
	g = color->green;
	b = color->blue;

	for (i = 0; i < image->width * image->height; i++) {
		alpha = *(d + 3);
		nalpha = 255 - alpha;

		*d = (((int)*d * alpha) + (r * nalpha)) / 256;
		d++;
		*d = (((int)*d * alpha) + (g * nalpha)) / 256;
		d++;
		*d = (((int)*d * alpha) + (b * nalpha)) / 256;
		d++;
		d++;
	}
}

RImage *RMakeTiledImage(RImage * tile, unsigned width, unsigned height)
{
	int x, y;
	unsigned w;
	unsigned long tile_size = tile->width * tile->height;
	unsigned long tx = 0;
	RImage *image;
	unsigned char *s, *d;

	if (width == tile->width && height == tile->height)
		image = RCloneImage(tile);
	else if (width <= tile->width && height <= tile->height)
		image = RGetSubImage(tile, 0, 0, width, height);
	else {
		int has_alpha = HAS_ALPHA(tile);

		image = RCreateImage(width, height, has_alpha);

		d = image->data;
		s = tile->data;

		for (y = 0; y < height; y++) {
			for (x = 0; x < width; x += tile->width) {

				w = (width - x < tile->width) ? width - x : tile->width;

				if (has_alpha) {
					w *= 4;
					memcpy(d, s + tx * 4, w);
				} else {
					w *= 3;
					memcpy(d, s + tx * 3, w);
				}
				d += w;
			}

			tx = (tx + tile->width) % tile_size;
		}
	}
	return image;
}

RImage *RMakeCenteredImage(RImage * image, unsigned width, unsigned height, RColor * color)
{
	int x, y, w, h, sx, sy;
	RImage *tmp;

	tmp = RCreateImage(width, height, HAS_ALPHA(image));
	if (!tmp) {
		return NULL;
	}

	RFillImage(tmp, color);

	if (image->height < height) {
		h = image->height;
		y = (height - h) / 2;
		sy = 0;
	} else {
		sy = (image->height - height) / 2;
		y = 0;
		h = height;
	}
	if (image->width < width) {
		w = image->width;
		x = (width - w) / 2;
		sx = 0;
	} else {
		sx = (image->width - width) / 2;
		x = 0;
		w = width;
	}
	RCombineArea(tmp, image, sx, sy, w, h, x, y);

	return tmp;
}