/*
 * Portions of this file are copyright Rebirth contributors and licensed as
 * described in COPYING.txt.
 * Portions of this file are copyright Parallax Software and licensed
 * according to the Parallax license below.
 * See COPYING.txt for license details.

THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

/*
 *
 * Graphical routines for manipulating grs_bitmaps.
 *
 */

#include <algorithm>
#include <stdexcept>
#include <stdlib.h>
#include <stdio.h>
#include "u_mem.h"
#include "gr.h"
#include "grdef.h"
#include "dxxerror.h"
#ifdef OGL
#include "ogl_init.h"
#endif
#include "bitmap.h"

#include "compiler-make_unique.h"

// Allocated a bitmap and makes its data be raw_data that is already somewhere.
static grs_bitmap_ptr gr_create_bitmap_raw(uint16_t w, uint16_t h, unsigned char * raw_data);

void gr_set_bitmap_data (grs_bitmap &bm, unsigned char *data)
{
#ifdef OGL
	ogl_freebmtexture(bm);
#endif
	bm.bm_data = data;
}

grs_bitmap_ptr gr_create_bitmap(uint16_t w, uint16_t h )
{
	unsigned char *d;
	MALLOC(d, unsigned char, MAX_BMP_SIZE(w, h));
	return gr_create_bitmap_raw (w, h, d);
}

grs_bitmap_ptr gr_create_bitmap_raw(uint16_t w, uint16_t h, unsigned char * raw_data )
{
	auto n = make_unique<grs_main_bitmap>();
	gr_init_bitmap(*n.get(), 0, 0, 0, w, h, w, raw_data);
	return n;
}

void gr_init_bitmap(grs_bitmap &bm, uint8_t mode, uint16_t x, uint16_t y, uint16_t w, uint16_t h, uint16_t bytesperline, unsigned char * data ) // TODO: virtualize
{
	bm.bm_x = x;
	bm.bm_y = y;
	bm.bm_w = w;
	bm.bm_h = h;
	bm.bm_flags = 0;
	bm.set_type(mode);
	bm.bm_rowsize = bytesperline;

	bm.bm_data = nullptr;
#ifdef OGL
	bm.bm_parent = nullptr;
	bm.gltexture = nullptr;
#endif
	gr_set_bitmap_data(bm, data);
}

void gr_init_bitmap_alloc(grs_bitmap &bm, uint8_t mode, uint16_t x, uint16_t y, uint16_t w, uint16_t h, uint16_t bytesperline)
{
	unsigned char *d;
	MALLOC(d, unsigned char, MAX_BMP_SIZE(w, h));
	gr_init_bitmap(bm, mode, x, y, w, h, bytesperline, d);
}

void gr_init_bitmap_data (grs_bitmap &bm) // TODO: virtulize
{
	bm.bm_data = nullptr;
	bm.bm_parent = nullptr;
#ifdef OGL
	bm.gltexture = nullptr;
#endif
}

grs_subbitmap_ptr gr_create_sub_bitmap(grs_bitmap &bm, uint16_t x, uint16_t y, uint16_t w, uint16_t h)
{
	auto n = make_unique<grs_subbitmap>();
	gr_init_sub_bitmap(*n.get(), bm, x, y, w, h);
	return n;
}

void gr_free_bitmap_data (grs_bitmap &bm) // TODO: virtulize
{
#ifdef OGL
	ogl_freebmtexture(bm);
#endif
	if (bm.bm_mdata != NULL)
		d_free (bm.bm_mdata);
}

void gr_init_sub_bitmap (grs_bitmap &bm, grs_bitmap &bmParent, uint16_t x, uint16_t y, uint16_t w, uint16_t h )	// TODO: virtualize
{
	uint32_t subx = x + bmParent.bm_x;
	uint32_t suby = y + bmParent.bm_y;
	if (subx != (bm.bm_x = static_cast<uint16_t>(subx)) ||
		suby != (bm.bm_y = static_cast<uint16_t>(suby)))
		throw std::overflow_error("offset overflow");
	bm.bm_w = w;
	bm.bm_h = h;
	bm.bm_flags = bmParent.bm_flags;
	bm.set_type(bmParent.get_type());
	bm.bm_rowsize = bmParent.bm_rowsize;

#ifdef OGL
	bm.gltexture = bmParent.gltexture;
#endif
	bm.bm_parent = &bmParent;
	bm.bm_data = &bmParent.bm_data[(unsigned int)((y*bmParent.bm_rowsize)+x)];
}

void decode_data(ubyte *data, uint_fast32_t num_pixels, array<color_t, 256> &colormap, array<unsigned, 256> &count)
{
	const auto a = [&](uint8_t mapped) {
		return ++count[mapped], colormap[mapped];
	};
	std::transform(data, data + num_pixels, data, a);
}

static void gr_set_super_transparent(grs_bitmap &bm, bool bOpaque)
{
	auto bm_flags = bm.bm_flags;
	gr_set_bitmap_flags(bm, bOpaque ? bm_flags & ~BM_FLAG_SUPER_TRANSPARENT : bm_flags | BM_FLAG_SUPER_TRANSPARENT);
}

void build_colormap_good(palette_array_t &palette, array<color_t, 256> &colormap, array<unsigned, 256> &freq)
{
	for (uint_fast32_t i = 0; i != colormap.size(); ++i)
	{
		auto &p = palette[i];
		int r = p.r;
		int g = p.g;
		int b = p.b;
 		colormap[i] = gr_find_closest_color( r, g, b );
		freq[i] = 0;
	}
}

void gr_remap_bitmap( grs_bitmap * bmp, palette_array_t &palette, int transparent_color, int super_transparent_color )
{
	array<uint8_t, 256> colormap;
	array<unsigned, 256> freq;

	if (bmp->get_type() != BM_LINEAR)
		return;	 //can't do it

	// This should be build_colormap_asm, but we're not using invert table, so...
	build_colormap_good( palette, colormap, freq );

	if ( (super_transparent_color>=0) && (super_transparent_color<=255))
		colormap[super_transparent_color] = 254;

	if ( (transparent_color>=0) && (transparent_color<=255))
		colormap[transparent_color] = TRANSPARENCY_COLOR;

	decode_data(bmp->get_bitmap_data(), bmp->bm_w * bmp->bm_h, colormap, freq );

	if ( (transparent_color>=0) && (transparent_color<=255) && (freq[transparent_color]>0) )
		gr_set_transparent(*bmp, 1);

	if ( (super_transparent_color>=0) && (super_transparent_color<=255) && (freq[super_transparent_color]>0) )
		gr_set_super_transparent(*bmp, 0);
}

void gr_remap_bitmap_good(grs_bitmap &bmp, palette_array_t &palette, uint_fast32_t transparent_color, uint_fast32_t super_transparent_color)
{
	array<uint8_t, 256> colormap;
	array<unsigned, 256> freq;
	build_colormap_good( palette, colormap, freq );

	if (super_transparent_color < colormap.size())
		colormap[super_transparent_color] = 254;

	if (transparent_color < colormap.size())
		colormap[transparent_color] = TRANSPARENCY_COLOR;

	if (bmp.bm_w == bmp.bm_rowsize)
		decode_data(bmp.get_bitmap_data(), bmp.bm_w * bmp.bm_h, colormap, freq );
	else {
		auto p = bmp.get_bitmap_data();
		for (uint_fast32_t y = bmp.bm_h; y--; p += bmp.bm_rowsize)
			decode_data(p, bmp.bm_w, colormap, freq );
	}

	if (transparent_color < freq.size() && freq[transparent_color])
		gr_set_transparent(bmp, 1);

	if (super_transparent_color < freq.size() && freq[super_transparent_color])
		gr_set_super_transparent(bmp, 1);
}

void gr_bitmap_check_transparency( grs_bitmap * bmp )
{
	auto data = bmp->bm_data;
	const uint_fast32_t bm_h = bmp->bm_h;
	const uint_fast32_t bm_w = bmp->bm_w;
	const uint_fast32_t stride = bmp->bm_rowsize - bm_w;
	for (uint_fast32_t y = 0; y != bm_h; ++y)
	{
		for (uint_fast32_t x = 0; x != bm_w; ++x)
		{
			if (*data++ == TRANSPARENCY_COLOR )	{
				gr_set_transparent(*bmp, 1);
				return;
			}
		}
		data += stride;
	}
	bmp->bm_flags = 0;
}