/*
TEXTURE_PAGE.C

symbols in this file:
0010F530 0040:
	_texture_page_fraction_used (0000)
0010F570 0060:
	_code_0010f570 (0000)
0010F5D0 00d0:
	_texture_page_new (0000)
0010F6A0 0030:
	_texture_page_delete (0000)
0010F6D0 0040:
	_texture_page_textures_begin (0000)
0010F710 0020:
	_texture_page_texture_get (0000)
0010F730 0060:
	_code_0010f730 (0000)
0010F790 02e0:
	_code_0010f790 (0000)
0010FA70 00f0:
	_texture_page_texture_new (0000)
0010FB60 00c0:
	_texture_page_textures_cancel (0000)
0010FC20 0070:
	_texture_page_textures_end (0000)
0010FC90 0030:
	_texture_page_texture_delete (0000)
0010FCC0 0060:
	_texture_page_resize (0000)
0027EAA0 0030:
	??_C@_0DA@DKBKMAEG@texture_page?9?$DOwidth?$DO0?5?$CG?$CG?5texture@ (0000)
0027EAD0 000d:
	??_C@_0N@NODJNJNK@texture_page?$AA@ (0000)
0027EAE0 0025:
	??_C@_0CF@GEHOPDBO@c?3?2halo?2SOURCE?2memory?2texture_pa@ (0000)
0027EB08 0016:
	??_C@_0BG@FAEHOIGE@texture?5page?5textures?$AA@ (0000)
0027EB20 001e:
	??_C@_0BO@PCBMOGEN@page_width?$DO0?5?$CG?$CG?5page_height?$DO0?$AA@ (0000)
0027EB40 002a:
	??_C@_0CK@JEDIHMHK@?$CBtexture_page?9?$DOcontains_unsorted@ (0000)
0027EB6C 0027:
	??_C@_0CH@KHJKPFFE@channel_count?$DMMAXIMUM_TEXTURE_CH@ (0000)
0027EB98 0059:
	??_C@_0FJ@FLDCNMDK@texture_page?9?$DOspacing?$DN?$DN0?5?$HM?$HM?5ceil@ (0000)
0027EBF4 0036:
	??_C@_0DG@MMDMAONB@immediate?5?$HM?$HM?5texture_page?9?$DOconta@ (0000)
0027EC2C 0011:
	??_C@_0BB@KPBIDJAC@resort_succeeded?$AA@ (0000)
0027EC40 0029:
	??_C@_0CJ@JJIPICBJ@texture_page?9?$DOcontains_unsorted_@ (0000)
00456628 0004:
	_bss_00456628 (0000)
*/

/* ---------- headers */

#include "cseries.h"
#include "data.h"
#include "math/integer_math.h"
#include "texture_page.h"

/* ---------- constants */

enum
{
	MAXIMUM_TEXTURE_CHANNELS = 512,
	MAXIMUM_TEXTURE_PAGE_INDICES = 0x8000
};

/* ---------- macros */

/* ---------- structures */

struct texture_page_channel
{
	short x;
	short y;
	short height;
};

typedef char texture_page_channel_size_assert[
	sizeof(struct texture_page_channel) == 6 ? 1 : -1];

/* ---------- prototypes */

static void code_0010f570(
	struct texture_page *texture_page);
static boolean code_0010f730(
	short texture_index_a,
	short texture_index_b);
boolean code_0010f790(
	struct texture_page *texture_page);
void qsort_2byte(
	short *elements,
	long element_count,
	boolean (*compare)(short, short));

/* ---------- globals */

struct texture_page *bss_00456628 = NULL;

/* ---------- public code */

float texture_page_fraction_used(
	struct texture_page *texture_page,
	boolean use_sorted_pixel_count)
{
	long pixel_count = use_sorted_pixel_count ? texture_page->used_pixel_count : texture_page->texture_pixel_count;

	return (float)pixel_count/(texture_page->width*texture_page->height);
}

struct texture_page *texture_page_new(
	void *user_data,
	short page_width,
	short page_height,
	short spacing)
{
	struct texture_page *texture_page = match_malloc(
		"c:\\halo\\SOURCE\\memory\\texture_page.c",
		29,
		sizeof(*texture_page));

	match_assert("c:\\halo\\SOURCE\\memory\\texture_page.c", 31, page_width>0 && page_height>0);
	if (texture_page)
	{
		csmemset(texture_page, 0, sizeof(*texture_page));
		texture_page->width = page_width;
		texture_page->height = page_height;
		texture_page->spacing = spacing;
		texture_page->user_data = user_data;
		texture_page->texture_pixel_count = 0;
		texture_page->used_pixel_count = 0;
		texture_page->contains_unsorted_textures = FALSE;
		texture_page->textures = data_new(
			"texture page textures",
			MAXIMUM_TEXTURES_PER_PAGE,
			sizeof(struct texture_page_texture));
		if (texture_page->textures)
		{
			data_make_valid(texture_page->textures);
			code_0010f570(texture_page);
			return texture_page;
		}

		{
			struct data_array *textures = texture_page->textures;
			texture_page = NULL;
			match_free("c:\\halo\\SOURCE\\memory\\texture_page.c", 56, textures);
		}
	}

	return texture_page;
}

void texture_page_delete(
	struct texture_page *texture_page)
{
	code_0010f570(texture_page);
	data_dispose(texture_page->textures);
	match_free("c:\\halo\\SOURCE\\memory\\texture_page.c", 69, texture_page);
	return;
}

void texture_page_textures_begin(
	struct texture_page *texture_page)
{
	code_0010f570(texture_page);
	match_assert("c:\\halo\\SOURCE\\memory\\texture_page.c", 78, !texture_page->contains_unsorted_textures);
	texture_page->contains_unsorted_textures = TRUE;
	return;
}

struct texture_page_texture *texture_page_texture_get(
	struct texture_page *texture_page,
	long texture_index)
{
	code_0010f570(texture_page);
	return datum_get(texture_page->textures, texture_index);
}

long texture_page_texture_new(
	struct texture_page *texture_page,
	short width,
	short height,
	boolean immediate)
{
	long texture_index = NONE;
	long texture_pixel_count;
	struct texture_page_texture *texture;

	code_0010f570(texture_page);
	match_assert(
		"c:\\halo\\SOURCE\\memory\\texture_page.c",
		96,
		immediate || texture_page->contains_unsorted_textures);
	if (
		width <= texture_page->width &&
		height <= texture_page->height)
	{
		texture_pixel_count = width*height;
		if (texture_page->texture_pixel_count+texture_pixel_count < texture_page->width*texture_page->height)
		{
			texture_index = datum_new(texture_page->textures);
			if (texture_index != NONE)
			{
				texture = texture_page_texture_get(texture_page, texture_index);
				texture->width = width;
				texture->height = height;
				texture->sorted = !texture_page->contains_unsorted_textures;
				texture_page->texture_pixel_count += texture_pixel_count;
				if (immediate && !code_0010f790(texture_page))
				{
					texture_page->texture_pixel_count -= texture_pixel_count;
					datum_delete(texture_page->textures, texture_index);
					return NONE;
				}
			}
		}
	}

	return texture_index;
}

void texture_page_textures_cancel(
	struct texture_page *texture_page)
{
	short absolute_index;
	struct texture_page_texture *texture;
	boolean resort_succeeded;

	code_0010f570(texture_page);
	match_assert(
		"c:\\halo\\SOURCE\\memory\\texture_page.c",
		138,
		texture_page->contains_unsorted_textures);
	texture = texture_page->textures->data;
	for (absolute_index = 0; absolute_index < texture_page->textures->count; absolute_index++, texture++)
	{
		if (texture->identifier && !texture->sorted)
		{
			texture_page->texture_pixel_count -= texture->width*texture->height;
			datum_delete(texture_page->textures, absolute_index);
		}
	}
	texture_page->contains_unsorted_textures = FALSE;
	resort_succeeded = code_0010f790(texture_page);
	match_assert("c:\\halo\\SOURCE\\memory\\texture_page.c", 157, resort_succeeded);
	return;
}

boolean texture_page_textures_end(
	struct texture_page *texture_page)
{
	short absolute_index;
	struct texture_page_texture *texture;
	boolean resort_succeeded;

	code_0010f570(texture_page);
	match_assert(
		"c:\\halo\\SOURCE\\memory\\texture_page.c",
		170,
		texture_page->contains_unsorted_textures);
	resort_succeeded = code_0010f790(texture_page);
	if (resort_succeeded)
	{
		texture = texture_page->textures->data;
		for (absolute_index = 0; absolute_index < texture_page->textures->count; absolute_index++, texture++)
		{
			if (texture->identifier)
				texture->sorted = TRUE;
		}
		texture_page->contains_unsorted_textures = FALSE;
	}
	return resort_succeeded;
}

void texture_page_texture_delete(
	struct texture_page *texture_page,
	long texture_index)
{
	code_0010f570(texture_page);
	datum_delete(texture_page->textures, texture_index);
	code_0010f790(texture_page);
	return;
}

boolean texture_page_resize(
	struct texture_page *texture_page,
	short width,
	short height)
{
	short old_width;
	short old_height;

	code_0010f570(texture_page);
	old_width = texture_page->width;
	old_height = texture_page->height;
	texture_page->width = width;
	texture_page->height = height;
	if (code_0010f790(texture_page))
		return TRUE;

	texture_page->width = old_width;
	texture_page->height = old_height;
	code_0010f790(texture_page);
	return FALSE;
}

/* ---------- private code */

static void code_0010f570(
	struct texture_page *texture_page)
{
	match_assert("c:\\halo\\SOURCE\\memory\\texture_page.c", 260, texture_page);
	match_assert("c:\\halo\\SOURCE\\memory\\texture_page.c", 261, texture_page->width>0 && texture_page->height>0);
	data_verify(texture_page->textures);
	return;
}

static __inline struct texture_page *texture_page_verify_and_return(
	struct texture_page *texture_page)
{
	code_0010f570(texture_page);
	return texture_page;
}

static boolean code_0010f730(
	short texture_index_a,
	short texture_index_b)
{
	struct texture_page *texture_page_a;
	struct texture_page *texture_page_b;
	struct texture_page_texture *texture_a;
	struct texture_page_texture *texture_b;
	long height_difference;

	texture_page_a = texture_page_verify_and_return(bss_00456628);
	texture_page_b = texture_page_verify_and_return(bss_00456628);
	texture_a = datum_get(texture_page_b->textures, texture_index_a);
	texture_b = datum_get(texture_page_a->textures, texture_index_b);
	height_difference = (long)texture_b->height - (long)texture_a->height;

	return height_difference > 0;
}

boolean code_0010f790(
	struct texture_page *texture_page)
{
	short texture_indices[MAXIMUM_TEXTURE_PAGE_INDICES];
	struct texture_page_channel channels[MAXIMUM_TEXTURE_CHANNELS];
	short texture_count;
	word spacing;
	word spacing_mask;
	short channel_count;
	short sorted_texture_index;
	struct texture_page_texture *texture;
	short texture_height;
	short texture_width;
	struct texture_page_channel *channel;

	match_assert(
		"c:\\halo\\SOURCE\\memory\\texture_page.c",
		292,
		texture_page->spacing==0 || ceiling_power2(texture_page->spacing)==texture_page->spacing);
	code_0010f570(texture_page);

	texture_count = 0;
	{
		short absolute_index;
		texture = texture_page->textures->data;

		for (absolute_index = 0; absolute_index < texture_page->textures->count; absolute_index++, texture++)
		{
			if (texture->identifier)
				texture_indices[texture_count++] = absolute_index;
		}
	}

	bss_00456628 = texture_page;
	qsort_2byte(texture_indices, texture_count, code_0010f730);
	spacing = texture_count>1 ? texture_page->spacing : 0;
	spacing_mask = spacing ? ceiling_power2((word)spacing)-1 : 0;

	texture_page->used_pixel_count = 0;
	channel_count = 1;
	channels[0].x = 0;
	channels[0].y = 0;
	channels[0].height = texture_page->height;

	for (sorted_texture_index = 0; sorted_texture_index < texture_count; sorted_texture_index++)
	{
		short channel_index;
		short masked_dimension;

		texture = texture_page_texture_get(
			texture_page,
			texture_indices[sorted_texture_index]);
		texture_width = (short)(texture->width + 2*spacing);
		texture_height = (short)(texture->height + 2*spacing);
		masked_dimension = texture_width;
		if ((masked_dimension &= (short)spacing_mask) != 0)
			texture_width = (short)((texture_width&~spacing_mask)+spacing);
		masked_dimension = texture_height;
		if ((masked_dimension &= (short)spacing_mask) != 0)
			texture_height = (short)((texture_height&~spacing_mask)+spacing);

		for (channel_index = 0; channel_index < channel_count; channel_index++)
		{
			struct texture_page_channel *test_channel = &channels[channel_index];

			if (
				texture_width <= texture_page->width-test_channel->x &&
				texture_height <= test_channel->height)
				break;
		}
		if (channel_index >= channel_count)
			return FALSE;

		channel = &channels[channel_index];
		{
			short remaining_height = (short)(channel->height-texture_height);

			texture->x = (short)(channel->x+spacing);
			texture->y = (short)(channel->y+spacing);
			if (remaining_height)
			{
				struct texture_page_channel *new_channel = &channels[channel_count++];

				match_assert(
					"c:\\halo\\SOURCE\\memory\\texture_page.c",
					360,
					channel_count<MAXIMUM_TEXTURE_CHANNELS);
				new_channel->x = channel->x;
				new_channel->y = (short)(channel->y+texture_height);
				new_channel->height = remaining_height;
			}
			channel->x = (short)(channel->x+texture_width);
			channel->height = texture_height;
			texture_page->used_pixel_count += texture_width*texture_height;
		}
	}

	return TRUE;
}