#include <stdlib.h>
#include <string.h>
#include "DrawSpan.h"
#include "polygon_pack.h"
#include "SpanPack.h"
#include "texture.h"
#include "viewer_types.h"

#define SPAN_PACK_LOAD 0
#define TEX_LOAD 1

SchedDefineTask(DrawSpan);

static unsigned char *tex;

void
DrawSpan::linebuf_init(int *buf, int x, int rgb)
{
    for (int i = 0; i < x; i++) {
	buf[i] = rgb;
    }
}

float*
DrawSpan::zRow_init(int w, int h)
{
    float *zRow = NULL;
    float z = 65535.0f;
    int length = w*h;

    zRow = (float*)smanager->allocate(sizeof(float)*length);

    for (int i = 0; i < length; i++) {
	zRow[i] = z;
    }

    return zRow;
}


char*
DrawSpan::get_pixel(int tx, int ty, void *texture_image)
{
#if 0
    return (char*)texture_image+(3*((128)*ty+tx));
#else
    return (char*)texture_image+(4*((8)*ty+tx));
#endif
}

Uint32
DrawSpan::get_rgb(int tx, int ty, void *texture)
{
    Uint8 red, green, blue, alpha;

    if (tx<0) tx = 0;
    if (128-1< tx) tx = 128-1 ;
    if (ty<0) ty = 0;
    if (128-1< ty) ty = 128-1 ;

#if 0
    char *p = get_pixel(tx,ty,texture);
#else
    void *texture_addr;

    int blockX = tx / 8;
    int blockY = ty / 8;
    void** addrList = (void**)global_get(TEXTURE2_ID);
    
    texture_addr = addrList[blockX + 16*blockY];
    smanager->dma_load(tex, (uint32)texture_addr, sizeof(uint32)*64, TEX_LOAD);
    smanager->dma_wait(TEX_LOAD);

    char *p = get_pixel(tx%8, ty%8, tex);
#endif
    
    blue  = (Uint8) p[0];
    green = (Uint8) p[1];
    red   = (Uint8) p[2];
    alpha = 255;

    return (red & 0xff) * 0x10000 + (green & 0xff) * 0x100
	+ (blue & 0xff) + (alpha << 24);
}

int
DrawSpan::run(void *rbuf, void *wbuf)
{
    SpanPack *sp = (SpanPack*)smanager->get_input(0);
    SpanPack *next_sp =
	(SpanPack*)smanager->allocate(sizeof(SpanPack));
    SpanPack *free_sp = next_sp; // next_sp の free() 用
    SpanPack *tmp_sp = NULL;
    Span *span;

    int render_y = sp->info.y_top;
    void *texture_image = global_get(TEXTURE_ID);

    int rangex_start  = get_param(0); // このタスクが担当する x の範囲の始点
    int rangex_end    = get_param(1); // 終点 (start <= x <= end)
    int rangey        = get_param(2); // y の範囲 (render_y + rangey - 1)
    int rangex        = rangex_end - rangex_start + 1;

    float *zRow = zRow_init(rangex, rangey);

    int **linebuf = (int**)smanager->allocate(sizeof(int*)*rangey);

    tex = (unsigned char*)smanager->allocate(sizeof(unsigned char)*64*4);

    for (int i = 0; i < rangey; i++) {
	linebuf[i] = (int*)smanager->get_output(i);
	//linebuf_init(linebuf[i], rangex, 0x00ff00ff);
	linebuf_init(linebuf[i], rangex, 0);
    }

    do {
	/**
	 * SpanPack->next が存在する場合、
	 * 現在の SpanPack を処理してる間に
	 * 次の SpanPack の DMA 転送を行う
	 */
	if (sp->next != NULL) {
	    smanager->dma_load(next_sp, (uint32)sp->next,
			       sizeof(SpanPack), SPAN_PACK_LOAD);
	} else {
	    next_sp = NULL;
	}

	for (int t = 0; t < sp->info.size; t++) {	  
	    span = &sp->span[t];

	    int end = span->length_x;
	    Uint32 rgb = 0x00ff00;
	    float tex1 = span->tex_x1;
	    float tex2 = span->tex_x2;
	    float tey1 = span->tex_y1;
	    float tey2 = span->tex_y2;
	    int tex_xpos;
	    int tex_ypos;
	    int tex_zpos;
	    int x = span->x;
	    int y = span->y;
	    float z = span->start_z;
	    float zpos = span->end_z;

	    // 座標が [0 .. split_screen_w-1] に入るように x,y を -1
	    int localx = getLocalX(x-1);
	    int localy = getLocalY(y-1);
	    
	    if (end == 1) {
		if (x < rangex_start || rangex_end < x) {
		    continue;
		}

		tex_xpos = (int)((span->tex_height-1) * tex1);
		tex_ypos = (int)((span->tex_width-1) * tey1);
		tex_zpos = (int)z;

		if (zpos < zRow[localx + (rangex * localy)]) {
		    rgb = get_rgb(tex_xpos, tex_ypos, texture_image);
		    zRow[localx + (rangex * localy)] = zpos;
		    linebuf[localy][localx] = rgb;
		}
	    } else {
		float tex_x, tex_y, tex_z;
		int js = (x < rangex_start) ? rangex_start - x : 0;
		int je = (x + end > rangex_end) ? rangex_end - x : end;

		for (int j = js; j <= je; j++) {
		    localx = getLocalX(x-1+j);

		    tex_x = tex1*(end-1-j)/(end-1) + tex2*j/(end-1);
		    tex_y = tey1*(end-1-j)/(end-1) + tey2*j/(end-1);
		    tex_z = z*(end-1-j)/(end-1) + zpos*j/(end-1);
		    if (tex_x > 1) tex_x = 1;
		    if (tex_y > 1) tex_y = 1;
		    tex_xpos = (int)((span->tex_height-1) * tex_x);
		    tex_ypos = (int)((span->tex_width-1) * tex_y);

		    if (tex_z < zRow[localx + (rangex*localy)]) {
			rgb = get_rgb(tex_xpos, tex_ypos, texture_image);
			zRow[localx + (rangex*localy)] = tex_z;
			linebuf[localy][localx] = rgb;
		    }
		}
	    }
	}
 
	smanager->dma_wait(SPAN_PACK_LOAD);

	tmp_sp = sp;
	sp = next_sp;
	next_sp = tmp_sp;
    } while (sp);

    free(free_sp);
    free(linebuf);
    free(zRow);
    free(tex);
    return 0;
}