#include "CreateSpan.h"
#include "viewer_types.h"

static const int SPAN_PACK_LOAD    =  5;
static const int SPAN_PACK_STORE   =  6;
static const int POLYGON_PACK_LOAD =  7;
static const int TILE_ALLOCATE     =  8;
static const int TILE_LOAD         =  9;
static const int TILE_STORE        = 10;

static SpanPackPtr spack = NULL;
static SpanPackPtr send_spack = NULL;
static int prev_index = 0;

SchedDefineTask(CreateSpan);

static float
calc(float f1, float f2,int i, float base)
{
    float ans;
    ans = f1/f2*i + base;
    return ans;
}


/**
 * TrianglePack から、vMin, vMid, vMax を求める
 *
 * @param [triPack] TrianglePack
 * @param [vMin] [vMid] [vMax]
 */
static void
make_vertex(TrianglePack *triPack,
	    VertexPackPtr *vMin, VertexPackPtr *vMid, VertexPackPtr *vMax)
{
    if (triPack->ver1.y <= triPack->ver2.y) {
	if (triPack->ver2.y <= triPack->ver3.y) {
	    *vMin = &triPack->ver1;
	    *vMid = &triPack->ver2;
	    *vMax = &triPack->ver3;
	} else if (triPack->ver3.y <= triPack->ver1.y) {
	    *vMin = &triPack->ver3;
	    *vMid = &triPack->ver1;
	    *vMax = &triPack->ver2;
	} else {
	    *vMin = &triPack->ver1;
	    *vMid = &triPack->ver3;
	    *vMax = &triPack->ver2;
	}
    } else {
	if (triPack->ver1.y <= triPack->ver3.y) {
	    *vMin = &triPack->ver2;
	    *vMid = &triPack->ver1;
	    *vMax = &triPack->ver3;
	} else if (triPack->ver3.y <= triPack->ver2.y) {
	    *vMin = &triPack->ver3;
	    *vMid = &triPack->ver2;
	    *vMax = &triPack->ver1;
	} else {
	    *vMin = &triPack->ver2;
	    *vMid = &triPack->ver3;
	    *vMax = &triPack->ver1;
	}
    }
}

static void
make_vMid10(VertexPack *v, VertexPack *vMin,
	    VertexPack *vMid, VertexPack *vMax)
{
    //int d, d1;
    float d;
    int d1;
    
    d  = vMax->y - vMin->y;
    d1 = (int)(vMid->y - vMin->y);

    v->tex_x  = calc(vMax->tex_x - vMin->tex_x, d, d1, vMin->tex_x);
    v->tex_y  = calc(vMax->tex_y - vMin->tex_y, d, d1, vMin->tex_y);
    v->x      = calc(vMax->x - vMin->x, d, d1, vMin->x);
    v->y      = vMid->y;
    v->z      = calc(vMax->z - vMin->z, d, d1, vMin->z);
}

/**
 * テクスチャは、TEXTURE_SPLIT_PIXEL^2 のブロックに分割する
 *
 * +---+---+---+---+---+---+
 * | 0 | 1 | 2 | 3 | 4 | 5 |
 * +---+---+---+---+---+---+
 * |   |   |   |   |   |11 |
 * +---+---+---+---+---+---+
 * |   |   |   |   |   |17 |
 * +---+---+---+---+---+---+
 * |   |   |   |   |   |23 |
 * +---+---+---+---+---+---+
 * |   |   |   |   |   |29 |
 * +---+---+---+---+---+---+
 * |   |   |   |   |   |35 |
 * +---+---+---+---+---+---+
 *
 * 一辺を TEXTURE_SPLIT とする
 * 各ブロックの数字がブロックIDとなる。
 */

/**
 * テクスチャの座標から、
 * テクスチャのどのブロックかを求める
 *
 * @param[in] tx X coordinates of texture
 * @param[in] tx Y coordinates of texture
 * @param[in] twidth  Width of texture
 * @return block ID
 */
static int
get_tex_block(int tx, int ty, int twidth)
{
     int blockX, blockY;

     blockX = tx / TEXTURE_SPLIT_PIXEL;
     blockY = ty / TEXTURE_SPLIT_PIXEL;

     return blockX + (twidth/TEXTURE_SPLIT_PIXEL)*blockY;
}

/**
 * x軸に水平な辺を持つ三角形ポリゴンから、
 * Span を抜き出す
 */
void
CreateSpan::half_triangle(SpanPackPtr *spackList,
			  int charge_y_top, int charge_y_end,
			  uint32 *tex_addr, int tex_width, int tex_height, 
			  VertexPack *vMin,VertexPack *vMid,VertexPack *vMid10)
{
    float tmp_z,tmp_tex1, tmp_tex2 ,tmp_tey1,tmp_tey2;
    float tmp_xpos,tmp_end,tmp_zpos;
    float start_z, end_z;
    float start_tex_x, end_tex_x, start_tex_y, end_tex_y;
    int x, y, length;

#if 1
    // これじゃないと
    // テクスチャの貼りに微妙に隙間が。謎だ
    int start_y = (int)vMid->y;
    int end_y   = (int)vMin->y;
#else
    float start_y = vMid->y;
    float end_y   = vMin->y;
#endif
    float div_y = start_y - end_y;
    int k = 0;
    int l = 1;

    SpanPackPtr tmp_spack;

    /**
     * 三角形ポリゴンをx軸に水平に二つに分けようとして
     * ある一辺がすでに水平だった場合、つまり
     * (環境によっては、back slash が 円マークかも)
     *
     * |\
     * | \
     * |  \
     * -----
     *
     *
     * 上のようなポリゴンだった場合は、本来なら上の部分の三角形にだけ
     * half_triangle の処理をするべきだが、現在の処理だと
     * この half_triangle に「上の部分の三角形」と、
     * 「『下の部分の三角形と判断してしまった』直線」が来てしまう。
     * 直線の部分が来ると、calc() で 0 除算とかで、値不定で暴走するので
     * 現在はこれで代用。
     * half_triangle 呼ぶ前にこれを判断できれば良いかもしれない。
     * てかこんなんでいいのかよ。。。
     *
     */
#if 1
    if ((int)div_y == 0) {
	return;
    }
#else
    if (vMid10->x == vMin->x && vMid10->y == vMin->y) {
	return;
    }
#endif

    if (div_y < 0) {
	div_y = -div_y;
	k = 1;
	l = -1;
    }

    for (int i = k; i < (int)div_y+1; i++) {
	y = (int)vMin->y + i*l;

	/**
	 * 担当 y 範囲内
	 */
	if (charge_y_top <= y && y <= charge_y_end) {
	    // 1..8 を index0, 9..16 を index1 にするために y を -1
	    int index = (y-1) / split_screen_h;

	    /**
	     * 違う SpanPack を扱う場合、
	     * 現在の SpanPack をメインメモリに送り、
	     * 新しい SpanPack を取ってくる
	     */
	    if (index != prev_index) {
		tmp_spack = spack;
		spack = send_spack;
		send_spack = tmp_spack;

		smanager->dma_wait(SPAN_PACK_STORE);
		smanager->dma_store(send_spack, (uint32)spackList[prev_index],
				    sizeof(SpanPack), SPAN_PACK_STORE);
		
		smanager->dma_load(spack, (uint32)spackList[index],
				   sizeof(SpanPack), SPAN_PACK_LOAD);
		prev_index = index;
		smanager->dma_wait(SPAN_PACK_LOAD);
	    }

	    /**
	     * 書き込む SpanPack が満杯だったら
	     * メインメモリで allocate した領域 (next) を持ってきて
	     * 現在の spack->next につなぎ、next を次の spack とする。
	     */
	    if (spack->info.size >= MAX_SIZE_SPAN) {
		SpanPackPtr next;
		
		smanager->mainMem_alloc(0, sizeof(SpanPack));
		smanager->mainMem_wait();
		next = (SpanPackPtr)smanager->mainMem_get(0);
		
		spack->next = next;

		tmp_spack = spack;
		spack = send_spack;
		send_spack = tmp_spack;

		smanager->dma_wait(SPAN_PACK_STORE);
		smanager->dma_store(send_spack, (uint32)spackList[index],
				    sizeof(SpanPack), SPAN_PACK_STORE);

		spackList[index] = next;
		
		smanager->dma_load(spack, (uint32)spackList[index],
				   sizeof(SpanPack), SPAN_PACK_LOAD);
		smanager->dma_wait(SPAN_PACK_LOAD);
		spack->init((index+1)*split_screen_h);
	    }
	} else {
	    /**
	     * 担当範囲外だったら無視
	     */
	    continue;
	}
	
	tmp_xpos = calc(vMid10->x - vMin->x ,div_y, i, vMin->x);
	tmp_end  = calc(vMid->x  - vMin->x ,div_y, i, vMin->x);
	tmp_z    = calc(vMid10->z - vMin->z ,div_y, i, vMin->z);
	tmp_zpos = calc(vMid->z  - vMin->z ,div_y, i, vMin->z);

	length = (tmp_xpos > tmp_end)
	    ? (int)tmp_xpos - (int)tmp_end : (int)tmp_end - (int)tmp_xpos;
	if (length == 0) {
	    continue;
	}

	tmp_tex1 =((i/(div_y)) * vMid10->tex_x) +
	    ( ((div_y - i)/(div_y)) * vMin->tex_x);
	tmp_tex2 =( (i/(div_y)) * vMid->tex_x) +
	    ( ((div_y - i)/(div_y)) * vMin->tex_x);

	tmp_tey1 =( (i/(div_y)) * vMid10->tex_y) +
	    ( ((div_y - i)/(div_y)) * vMin->tex_y);
	tmp_tey2 =( (i/(div_y)) * vMid->tex_y) +
	    ( ((div_y - i)/(div_y)) * vMin->tex_y);

	if (tmp_xpos > tmp_end) {
	    x = (int)tmp_end;
	    /**
	     * +1 は要らない気がする・・・
	     */ 
	    //length = (int)(tmp_xpos)-(int)(tmp_end)+1;
	    length = (int)(tmp_xpos)-(int)(tmp_end);
	    start_z = tmp_zpos;
	    end_z = tmp_z;
	    start_tex_x = tmp_tex2;
	    end_tex_x = tmp_tex1;
	    start_tex_y = tmp_tey2;
	    end_tex_y = tmp_tey1;
	} else {
	    x = (int)tmp_xpos;
	    //length = (int)(tmp_end)-(int)(tmp_xpos)+1;
	    length = (int)(tmp_end)-(int)(tmp_xpos);
	    start_z = tmp_z;
	    end_z = tmp_zpos;
	    start_tex_x = tmp_tex1;
	    end_tex_x = tmp_tex2;
	    start_tex_y = tmp_tey1;
	    end_tex_y = tmp_tey2;
	}

	smanager->dma_wait(SPAN_PACK_LOAD);

	Span *span = &spack->span[spack->info.size++];

	span->tex_addr   = tex_addr;
	span->tex_width  = tex_width;
	span->tex_height = tex_height;
	span->x          = x;
	span->y          = y;
	span->length_x   = length;
	span->start_z    = start_z;
	span->end_z      = end_z;
	span->tex_x1     = start_tex_x;
	span->tex_x2     = end_tex_x;
	span->tex_y1     = start_tex_y;
	span->tex_y2     = end_tex_y;
    }
}


int
CreateSpan::run(void *rbuf, void *wbuf)
{
    PolygonPack *pp = (PolygonPack*)smanager->get_input(0);
    PolygonPack *next_pp = 
	(PolygonPack*)smanager->allocate(sizeof(PolygonPack));
    PolygonPack *free_pp = next_pp;
    PolygonPack *tmp_pp;

    TrianglePackPtr triPack;
    VertexPackPtr vMin, vMid, vMax;
    VertexPackPtr vMid10
	= (VertexPackPtr)smanager->allocate(sizeof(VertexPack));
    
    SpanPackPtr *spackList = (SpanPackPtr*)smanager->get_input(1);
    spack = (SpanPackPtr)smanager->get_input(2);
    send_spack = (SpanPackPtr)smanager->allocate(sizeof(SpanPack));
    prev_index = get_param(0);

    // spack と send_spack は swap しながら DMA を繰り返すので
    // 自分で allocate した send_spack を覚えてないといけない
    SpanPackPtr free_spack = send_spack;

    int charge_y_top = get_param(1);
    int charge_y_end = get_param(2);

    do {
	if (pp->next != NULL) {
	    smanager->dma_load(next_pp, (uint32)pp->next,
			       sizeof(PolygonPack), POLYGON_PACK_LOAD);
	} else {
	    next_pp = NULL;
	}

	for (int i = 0; i < pp->info.size; i++) {
	    triPack = &pp->tri[i];
	    
#if 0
	    make_vertex(triPack, &vMin, &vMid, &vMax);
#else
	    if (triPack->ver1.y <= triPack->ver2.y) {
		if (triPack->ver2.y <= triPack->ver3.y) {
		    vMin = &triPack->ver1;
		    vMid = &triPack->ver2;
		    vMax = &triPack->ver3;
		} else if (triPack->ver3.y <= triPack->ver1.y) {
		    vMin = &triPack->ver3;
		    vMid = &triPack->ver1;
		    vMax = &triPack->ver2;
		} else {
		    vMin = &triPack->ver1;
		    vMid = &triPack->ver3;
		    vMax = &triPack->ver2;
		}
	    } else {
		if (triPack->ver1.y <= triPack->ver3.y) {
		    vMin = &triPack->ver2;
		    vMid = &triPack->ver1;
		    vMax = &triPack->ver3;
		} else if (triPack->ver3.y <= triPack->ver2.y) {
		    vMin = &triPack->ver3;
		    vMid = &triPack->ver2;
		    vMax = &triPack->ver1;
		} else {
		    vMin = &triPack->ver2;
		    vMid = &triPack->ver3;
		    vMax = &triPack->ver1;
		}
	    }
#endif
	    make_vMid10(vMid10, vMin, vMid, vMax);

	    /**
	     * ポリゴンを、x軸に水平に分割して二つの三角形を作り、
	     * それぞれから Span を求める
	     */
	    half_triangle(spackList, charge_y_top, charge_y_end,
			  triPack->tex_addr, triPack->tex_width,
			  triPack->tex_height, vMin, vMid, vMid10);
	    half_triangle(spackList, charge_y_top, charge_y_end,
			  pp->tri[0].tex_addr, pp->tri[0].tex_width,
			  pp->tri[0].tex_height, vMax, vMid, vMid10);
	}

	smanager->dma_wait(POLYGON_PACK_LOAD);	

	tmp_pp = pp;
	pp = next_pp;
	next_pp = tmp_pp;
    } while (pp);

    smanager->dma_wait(SPAN_PACK_STORE);
    smanager->dma_store(spack, (uint32)spackList[prev_index],
			sizeof(SpanPack), SPAN_PACK_STORE);
    smanager->dma_wait(SPAN_PACK_STORE);

    free(free_pp);
    free(free_spack);
    free(vMid10);

    return 0;
}