/*
 * File      : dc_buffer.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2009, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2009-10-16     Bernard      first version
 */
#include <rtgui/rtgui.h>
#include <rtgui/dc.h>
#include <rtgui/dc_hw.h>
#include <rtgui/color.h>
#include <rtgui/rtgui_system.h>

struct rtgui_dc_buffer
{
	struct rtgui_dc parent;

	/* graphic context */
	rtgui_gc_t gc;

	/* width and height */
	rt_uint16_t width, height;
	rt_uint16_t pitch;

	/* blit info */
	rtgui_region_t clip;

	/* pixel data */
	rt_uint8_t* pixel;
};

static rt_bool_t rtgui_dc_buffer_fini(struct rtgui_dc* dc);
static void rtgui_dc_buffer_draw_point(struct rtgui_dc* dc, int x, int y);
static void rtgui_dc_buffer_draw_color_point(struct rtgui_dc* dc, int x, int y, rtgui_color_t color);
static void rtgui_dc_buffer_draw_vline(struct rtgui_dc* dc, int x, int y1, int y2);
static void rtgui_dc_buffer_draw_hline(struct rtgui_dc* dc, int x1, int x2, int y);
static void rtgui_dc_buffer_fill_rect (struct rtgui_dc* dc, struct rtgui_rect* rect);
static void rtgui_dc_buffer_blit(struct rtgui_dc* self, struct rtgui_point* dc_point,
	struct rtgui_dc* dest, rtgui_rect_t* rect);

static void rtgui_dc_buffer_set_gc (struct rtgui_dc* dc, rtgui_gc_t *gc);
static rtgui_gc_t* rtgui_dc_buffer_get_gc(struct rtgui_dc* dc);

static rt_bool_t rtgui_dc_buffer_get_visible(struct rtgui_dc* dc);
static void rtgui_dc_buffer_get_rect(struct rtgui_dc* dc, rtgui_rect_t* rect);

const static struct rtgui_dc_engine dc_buffer_engine = 
{
	rtgui_dc_buffer_draw_point,
	rtgui_dc_buffer_draw_color_point,
	rtgui_dc_buffer_draw_vline,
	rtgui_dc_buffer_draw_hline,
	rtgui_dc_buffer_fill_rect,
	rtgui_dc_buffer_blit,

	rtgui_dc_buffer_set_gc,
	rtgui_dc_buffer_get_gc,

	rtgui_dc_buffer_get_visible,
	rtgui_dc_buffer_get_rect,

	rtgui_dc_buffer_fini,
};

struct rtgui_dc* rtgui_dc_buffer_create(int w, int h)
{
	struct rtgui_dc_buffer* dc;

	dc = (struct rtgui_dc_buffer*)rtgui_malloc(sizeof(struct rtgui_dc_buffer));
	dc->parent.type   = RTGUI_DC_BUFFER;
	dc->parent.engine = &dc_buffer_engine;
	dc->gc.foreground = default_foreground;
	dc->gc.background = default_background;
	dc->gc.font = rtgui_font_default();
	dc->gc.textalign = RTGUI_ALIGN_LEFT | RTGUI_ALIGN_TOP;

	dc->width	= w;
	dc->height	= h;
	dc->pitch	= w * sizeof(rtgui_color_t);

	rtgui_region_init(&(dc->clip));

	dc->pixel = rtgui_malloc(h * dc->pitch);
	rt_memset(dc->pixel, 0, h * dc->pitch);

	return &(dc->parent);
}

rt_uint8_t* rtgui_dc_buffer_get_pixel(struct rtgui_dc* dc)
{
	struct rtgui_dc_buffer* dc_buffer;

	dc_buffer = (struct rtgui_dc_buffer*)dc;

	return dc_buffer->pixel;
}

static rt_bool_t rtgui_dc_buffer_fini(struct rtgui_dc* dc)
{
	struct rtgui_dc_buffer* buffer = (struct rtgui_dc_buffer*)dc;

	if (dc->type != RTGUI_DC_BUFFER) return RT_FALSE;

	rtgui_free(buffer->pixel);
	buffer->pixel = RT_NULL;

	return RT_TRUE;
}

static void rtgui_dc_buffer_draw_point(struct rtgui_dc* self, int x, int y)
{
	rtgui_color_t* ptr;
	struct rtgui_dc_buffer* dc;

	dc = (struct rtgui_dc_buffer*)self;

	/* note: there is no parameter check in this function */
	ptr = (rtgui_color_t*)(dc->pixel + y * dc->pitch + x * sizeof(rtgui_color_t));

	*ptr = dc->gc.foreground;
}

static void rtgui_dc_buffer_draw_color_point(struct rtgui_dc* self, int x, int y, rtgui_color_t color)
{
	rtgui_color_t* ptr;
	struct rtgui_dc_buffer* dc;

	dc = (struct rtgui_dc_buffer*)self;

	/* note: there is no parameter check in this function */
	ptr = (rtgui_color_t*)(dc->pixel + y * dc->pitch + x * sizeof(rtgui_color_t));

	*ptr = color;
}

static void rtgui_dc_buffer_draw_vline(struct rtgui_dc* self, int x, int y1, int y2)
{
	rtgui_color_t* ptr;
	register rt_base_t index;
	struct rtgui_dc_buffer* dc;

	dc = (struct rtgui_dc_buffer*)self;

	if (x  >= dc->width) return;
	if (y1 > dc->height) y1 = dc->height;
	if (y2 > dc->height) y2 = dc->height;

	ptr = (rtgui_color_t*)(dc->pixel + y1 * dc->pitch + x * sizeof(rtgui_color_t));
	for (index = y1; index < y2; index ++)
	{
		/* draw this point */
		*ptr = dc->gc.foreground;
		ptr += dc->width;
	}
}

static void rtgui_dc_buffer_draw_hline(struct rtgui_dc* self, int x1, int x2, int y)
{
	rtgui_color_t* ptr;
	register rt_base_t index;
	struct rtgui_dc_buffer* dc;

	dc = (struct rtgui_dc_buffer*)self;
	if (y >= dc->height) return;
	if (x1 > dc->width) x1 = dc->width;
	if (x2 > dc->width) x2 = dc->width;

	ptr = (rtgui_color_t*)(dc->pixel + y * dc->pitch + x1 * sizeof(rtgui_color_t));
	for (index = x1; index < x2; index ++)
	{
		/* draw this point */
		*ptr++ = dc->gc.foreground;
	}
}

static void rtgui_dc_buffer_fill_rect (struct rtgui_dc* self, struct rtgui_rect* rect)
{
	rtgui_rect_t r;
	struct rtgui_dc_buffer* dc;

	r = *rect;
	dc = (struct rtgui_dc_buffer*)self;
	if (r.x1 > dc->width) r.x1 = dc->width;
	if (r.x2 > dc->width) r.x2 = dc->width;
	if (r.y1 > dc->height) r.y1 = dc->height;
	if (r.y2 > dc->height) r.y2 = dc->height;

	/* fill first line */
	rtgui_dc_buffer_draw_hline(&(dc->parent), r.x1, r.x2, r.y1);

	/* memory copy other lines */
	if (r.y2 > r.y1)
	{
		register rt_base_t index;
		for (index = r.y1 + 1; index < r.y2; index ++)
		{
			rt_memcpy(dc->pixel + index * dc->pitch,
				dc->pixel + r.y1 * dc->pitch,
				(r.x2 - r.x1) * sizeof(rtgui_color_t));
		}
	}
}

/* rtgui_color to RGB323 */
rt_inline void rtgui_blit_line_1(rtgui_color_t* color, rt_uint8_t* dest, int line)
{
	struct _color {rt_uint8_t r, g, b, a;} *c;

	c = (struct _color*)color;
	while (line-- > 0)
	{
		*dest = (c->r & 0xe0) | (c->g & 0xc0) >> 3 | (c->b & 0xe0) >> 5 ;

		c ++;
		dest ++;
	}
}

/* rtgui_color to RGB565 */
rt_inline void rtgui_blit_line_2(rtgui_color_t* color, rt_uint8_t* dest, int line)
{
	struct _color {rt_uint8_t r, g, b, a;} *c;
	rt_uint16_t* ptr;

	c = (struct _color*)color;
	ptr = (rt_uint16_t*)dest;

	while (line-- > 0)
	{
		*ptr = ((c->r & 0xf8) << 8) | ((c->g & 0xfc) << 3) | (c->b >> 3);

		c ++;
		ptr ++;
	}
}

/* rtgui_color to RGB888 */
rt_inline void rtgui_blit_line_4(rtgui_color_t* color, rt_uint8_t* dest, int line)
{
	rt_memcpy(dest, color, line * 4);
}

/* blit a dc to a hardware dc */
static void rtgui_dc_buffer_blit(struct rtgui_dc* self, struct rtgui_point* dc_point, struct rtgui_dc* dest, rtgui_rect_t* rect)
{
	struct rtgui_dc_buffer* dc = (struct rtgui_dc_buffer*)self;
	struct rtgui_dc_hw* hw = (struct rtgui_dc_hw*)dest;

	if (dc_point == RT_NULL) dc_point = &rtgui_empty_point;

	if (dest->type == RTGUI_DC_HW)
	{
		rtgui_color_t* pixel;
		rt_uint8_t *line_ptr;
		rt_uint16_t rect_width, rect_height, index;
		void (*blit_line)(rtgui_color_t* color, rt_uint8_t* dest, int line);

		/* calculate correct width and height */
		if (rtgui_rect_width(*rect) > (dc->width - dc_point->x))
			rect_width = dc->width - dc_point->x;
		else
			rect_width = rtgui_rect_width(*rect);

		if (rtgui_rect_height(*rect) > (dc->height - dc_point->y))
			rect_height = dc->height - dc_point->y;
		else
			rect_height = rtgui_rect_height(*rect);

		/* get blit line function */
		switch (hw->device->byte_per_pixel)
		{
		case 1:
			blit_line = rtgui_blit_line_1;
			break;
		case 2:
			blit_line = rtgui_blit_line_2;
			break;

		case 4:
			blit_line = rtgui_blit_line_4;
			break;

		default:
			/* not support byte per pixel */
			return;
		}

		/* create line buffer */
		line_ptr = (rt_uint8_t*) rtgui_malloc(rect_width * hw->device->byte_per_pixel);

		/* prepare pixel line */
		pixel = (rtgui_color_t*)(dc->pixel + dc_point->y * dc->pitch + dc_point->x * sizeof(rtgui_color_t));

		/* draw each line */
		for (index = rect->y1; index < rect->y1 + rect_height; index ++)
		{
			/* blit on line buffer */
			blit_line(pixel, line_ptr, rect_width);
			pixel += dc->width;

			/* draw on hardware dc */
			rtgui_dc_hw_draw_raw_hline(hw, line_ptr, rect->x1, rect->x1 + rect_width, index);
		}

		/* release line buffer */
		rtgui_free(line_ptr);
	}
}


static void rtgui_dc_buffer_set_gc(struct rtgui_dc* self, rtgui_gc_t *gc)
{
	struct rtgui_dc_buffer* dc = (struct rtgui_dc_buffer*)self;

	dc->gc = *gc;
}

static rtgui_gc_t *rtgui_dc_buffer_get_gc(struct rtgui_dc* self)
{
	struct rtgui_dc_buffer* dc = (struct rtgui_dc_buffer*)self;

	return &dc->gc;
}

static rt_bool_t rtgui_dc_buffer_get_visible(struct rtgui_dc* dc)
{
	return RT_TRUE;
}

static void rtgui_dc_buffer_get_rect(struct rtgui_dc* self, rtgui_rect_t* rect)
{
	struct rtgui_dc_buffer* dc = (struct rtgui_dc_buffer*)self;

	rect->x1 = rect->y1 = 0;

	rect->x2 = dc->width;
	rect->y2 = dc->height;
}