求助！！！！！！！！！STM32的3D图形问题。

channinggo

综合实验里 3dplay.c 下有这么一段 void t3d_pixel_transform，这是是什么样的模型？ 求详述。

//核心算法部分

//3d转2D函数, pangle-旋转角度，ptrandis-移动位置, ppixel－要转换的像素, ppreturn-转换后的2D值保存到这

//pangle:角度.单位为弧度,而不是°.如果要用度表示的话,需要乘以π/180

//ptrandis:移动位置(当前点所围绕操作的点的坐标,3D像素点)

//ppixel:要转换的像素点(3D像素点)

//ppreturn:转换完成后的像素点(2D像素点)  

void t3d_pixel_transform(_t3d_obj* t3dx,u16 pixindex)

{  

signed long lsinx,lcosx,lsiny,lcosy,lsinz,lcosz;

signed long ltempx,ltempy,ltempz;

signed long ldx,ldy,ldz;  

    float tdx,tdy;//必须要的2个个浮点数据,否则在x/y轴上会有点问题.  

lsinx=my_sin(t3dx->ang.x);

  lcosx=my_cos(t3dx->ang.x);

lsiny=my_sin(t3dx->ang.y);

lcosy=my_cos(t3dx->ang.y);

lsinz=my_sin(t3dx->ang.z);

  lcosz=my_cos(t3dx->ang.z); 

    //开始计算和转换 

    ldx = t3dx->p3dbuf[pixindex].x;

ldy = t3dx->p3dbuf[pixindex].y;

ldz = t3dx->p3dbuf[pixindex].z;

    ltempy = ldy*lcosx - ldz*lsinx;

    ltempz = ldy*lsinx + ldz*lcosx;

    ldy = ltempy;

    ldz = ltempz;

    ltempx = ldx*lcosy*1000 - ldz*lsiny;

    ltempz = ldx*lsiny*1000 + ldz*lcosy;

    ldx = ltempx/1000;  

    ldz = ltempz/10000;//得到扩大100倍的结果

    ltempx = ldx * lcosz - ldy * lsinz;

    ltempy = ldx * lsinz + ldy * lcosz;

    ldx = ltempx/100000;

    ldy = ltempy/100000;  

    tdx = ldx + t3dx->dis.x*10;

tdy = ldy + t3dx->dis.y*10;

ldz = ldz - t3dx->dis.z*100 + t3dx->offz*100;   

  t3dx->p2dbuf[pixindex].x = (((tdx-USRX)*USRZ)/ldz) + t3dx->offx;

t3dx->p2dbuf[pixindex].y = (((tdy-USRY)*USRZ)/ldz) + t3dx->offy;    

t3dx->p2dbuf[pixindex].color=t3dx->p3dbuf[pixindex].color;    

  

}  

正点原子

照搬别人的代码.无解释.