java - 不同高度尺寸的射线铸件

标签 java math graphics raycasting 2d-3d-conversion

我有一个Java项目,它制作“windows迷宫”并使用射线转换算法。这是屏幕截图:

Maze made with ray casting

就像您看到的所有墙壁都具有相同的高度大小一样。我想做同样的事,但是高度大小不同

private void castRay(int xOnScreen,double angle,double direction) {
    R rx = castRayInX(angle,direction);
    R ry = castRayInY(angle,direction);
    // In case of out-of-space rays
    if (rx.getDistance()==Double.MAX_VALUE && ry.getDistance()==Double.MAX_VALUE) {
        graphics.setColor(BACKGROUND);
        graphics.drawLine(xOnScreen,0,xOnScreen,this.image.getHeight());
        return;
    }
    double distance = rx.getDistance();
    double normal = rx.getNormal();
    Color c = rx.getColor();
    double coef = Math.cos((angle+direction+Math.PI)-normal);
    Plot collision = rx.getPlot();

    if (ry.getDistance()<rx.getDistance()) {
        distance = ry.getDistance();
        normal = ry.getNormal();
        c = ry.getColor();
        coef = Math.cos((angle+direction+Math.PI)-normal);
        collision = ry.getPlot();
    }

    coef = Math.abs(coef);
    int factor = map.length*SQUARE_SIZE;
    double d = (double)(distance+factor)/factor;
    coef *= 1/(d*d);
    Color c2 = new Color((int)(c.getRed()*coef),(int)(c.getGreen()*coef),(int)(c.getBlue()*coef));
    graphics.setColor(c2);
//  graphics.setColor(c);  // no illumination
    distance *= Math.cos(angle); // lens correction
    int h = (int)(this.screenDistance/distance*WALL_HEIGHT); // perspective height
    int vh = this.image.getHeight();
    graphics.drawLine(xOnScreen,(vh-h)/2,xOnScreen,(vh+h)/2);
    drawEye(direction,collision);
}

private R castRayInX(double angleRay,double direction) {
    double angle = angleRay+direction;
    double x1 = eye.getX()+SQUARE_SIZE*Math.cos(angle);
    double y1 = eye.getY()+SQUARE_SIZE*Math.sin(angle);
    double slope = (y1-eye.getY())/(x1-eye.getX());
    if (Math.cos(angle)==0) {
        if (Math.sin(angle)>0)
            return new R(Double.MAX_VALUE,3*Math.PI/2,BACKGROUND,null);
        else
            return new R(Double.MAX_VALUE,Math.PI/2,BACKGROUND,null);
    }
    if (Math.cos(angle)>0) {
        int firstX = ((eye.getX()/SQUARE_SIZE)+1)*SQUARE_SIZE;
        R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
        for (int x = firstX; x<map[0].length*SQUARE_SIZE; x += SQUARE_SIZE) {
            int y = (int)(slope*(x-eye.getX())+eye.getY());
            if (isOutside(x,y,Color.MAGENTA,this.showRayCastingX)) break;
            Color c = colorAt(x,y);
            if (c==null) c = colorAt(x,y-1);
            if (c==null) c = colorAt(x-1,y);
            if (c==null) c = colorAt(x-1,y-1);
            if (c!=null) {
                int DX = x-eye.getX();
                double DY = y-eye.getY();
                return new R(Math.sqrt(DX*DX+DY*DY),Math.PI,c,new Plot((int)x,(int)y, WALL_HEIGHT));
            }
        }
        return r;
    } else {
        int firstX = ((eye.getX()/SQUARE_SIZE))*SQUARE_SIZE;
        R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
        for (int x = firstX; x>=0; x -= SQUARE_SIZE) {
            int y = (int)(slope*(x-eye.getX())+eye.getY());
            if (isOutside(x,y,Color.MAGENTA,this.showRayCastingX)) break;
            Color c = colorAt(x,y);
            if (c==null) c = colorAt(x,y-1);
            if (c==null) c = colorAt(x-1,y);
            if (c==null) c = colorAt(x-1,y-1);
            if (c!=null) {
                int DX = x-eye.getX();
                double DY = y-eye.getY();
                return new R(Math.sqrt(DX*DX+DY*DY),0,c,new Plot((int)x,(int)y, WALL_HEIGHT));
            }
        }
        return r;           
    }
}
private R castRayInY(double angleRay,double direction) {
//  System.out.println("cast ray 2 Y "+angleRay+" "+direction);
    double angle = angleRay+direction;
    double x1 = eye.getX()+SQUARE_SIZE*Math.cos(angle);
    double y1 = eye.getY()+SQUARE_SIZE*Math.sin(angle);
//  System.out.println(eye+" "+x1+" "+y1);
    double slope = (y1-eye.getY())/(x1-eye.getX());
    if (Math.sin(angle)==0) {
        if (Math.cos(angle)>0)
            return new R(Double.MAX_VALUE,Math.PI,BACKGROUND,null);
        else
            return new R(Double.MAX_VALUE,0,BACKGROUND,null);
    }
    if (Math.sin(angle)>0) {
        int firstY = ((eye.getY()/SQUARE_SIZE)+1)*SQUARE_SIZE;
        R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
        for (int y = firstY; y<map.length*SQUARE_SIZE; y += SQUARE_SIZE) {
            int x = (int)((y-eye.getY())/slope)+eye.getX();
            if (isOutside(x,y,Color.CYAN,this.showRayCastingY)) break;
            Color c = colorAt(x,y);
            if (c==null) c = colorAt(x,y-1);
            if (c==null) c = colorAt(x-1,y);
            if (c==null) c = colorAt(x-1,y-1);
            if (c!=null) {
                double DX = x-eye.getX();
                int DY = y-eye.getY();
                return new R(Math.sqrt(DX*DX+DY*DY),3*Math.PI/2,c,new Plot((int)x,(int)y, WALL_HEIGHT));
                }
            }
            return r;
        } else {
            int firstY = ((eye.getY()/SQUARE_SIZE))*SQUARE_SIZE;
            R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
            for (int y = firstY; y>=0; y -= SQUARE_SIZE) {
                int x = (int)((y-eye.getY())/slope)+eye.getX();
                if (isOutside(x,y,Color.CYAN,this.showRayCastingY)) break;
                Color c = colorAt(x,y);
                if (c==null) c = colorAt(x,y-1);
                if (c==null) c = colorAt(x-1,y);
                if (c==null) c = colorAt(x-1,y-1);
                if (c!=null) {
                    double DX = x-eye.getX();
                    int DY = y-eye.getY();
                    return new R(Math.sqrt(DX*DX+DY*DY),Math.PI/2,c,new Plot((int)x,(int)y, WALL_HEIGHT));
                }
            }
            return r;           
        }
    }

我的R类具有Plot (x, y, z),现在我将WALL_HEIGHT使用的是颜色,距离和法线。目前,这是可行的,但是我想添加一个新函数,例如castRayInZ,但是我没有所有的数学理论都在后面。我的迷宫是由这样的 map 制成的:
private String [][]map = {  // each: SQUARE_SIZE x SQUARE_SIZE
        { "Y300", "Z500", "X230", "Y112", "Z321", "X120", "X354" },
        { "X89", " ", " ", " ", "Y120", " ", "X232" },
        { "Z124", " ", "X276", " ", "X123", " ", "X" },
        { "Y290", " ", " ", " ", " ", " ", "X100" },
        { "X32", "Z430", " ", "Y500", "X120", " ", "X123" },
        { "X222", " ", " ", " ", " ", " ", "X210" },
        { "X12", "Y98", "Y763", "X146", "Y111", "Y333", "X321" }

其中X Y Z代表颜色(X代表红色,Y代表绿色,Z代表蓝色,仅测试我的灯光功能),我为 map 的每个正方形添加一个高度。我现在将所有长度都设置为SQUARE_LENGTH,也许以后再将每个正方形的大小减小到一个像素,并通过生成它来放大 map 。但是我真的很想知道如何更改每个正方形的高度。我从4天开始研究它,没有任何线索...

编辑

我有一些消息,我改变了墙的大小,但是我有一些奇怪的东西,这是一个屏幕截图:

Strange stuff image

就像您看到的一样,这里有些奇怪的事情出现了。这是我的代码:
private void castRay(int xOnScreen,double angle,double direction) {
    R rx = castRayInX(angle,direction);
    R ry = castRayInY(angle,direction);
    // In case of out-of-space rays
    if (rx.getDistance()==Double.MAX_VALUE && ry.getDistance()==Double.MAX_VALUE) {
        graphics.setColor(BACKGROUND);
        graphics.drawLine(xOnScreen,0,xOnScreen,this.image.getHeight());
        return;
    }
    double distance = rx.getDistance();
    double normal = rx.getNormal();
    Color c = rx.getColor();
    double coef = Math.cos((angle+direction+Math.PI)-normal);
    Plot collision = rx.getPlot();

    if (ry.getDistance()<rx.getDistance()) {
        distance = ry.getDistance();
        normal = ry.getNormal();
        c = ry.getColor();
        coef = Math.cos((angle+direction+Math.PI)-normal);
        collision = ry.getPlot();
    }

    coef = Math.abs(coef);
    int factor = map.length*SQUARE_SIZE;
    double d = (double)(distance+factor)/factor;
    coef *= 1/(d*d);
    Color c2 = new Color((int)(c.getRed()*coef),(int)(c.getGreen()*coef),(int)(c.getBlue()*coef));
graphics.setColor(c);
    distance *= Math.cos(angle); // lens correction
    int h;
    int hw = (int)(this.screenDistance/distance*WALL_HEIGHT); //WALL_HEIGHT value is 300px at default
    if(rx.getPlot() != null)
        h = (int)(this.screenDistance/distance*rx.getPlot().getZ()); // perspective height
    else
        h = (int)(this.screenDistance/distance*WALL_HEIGHT);
    int vh = this.image.getHeight();
    int y0 = (hw+vh)/2;
    int y1 = (vh-h)/2;
    graphics.drawLine(xOnScreen,y0,xOnScreen,y1);
    drawEye(direction,collision);

我的问题应该来自castRayInX函数:
private R castRayInX(double angleRay,double direction) {
    double angle = angleRay+direction;
    double x1 = eye.getX()+SQUARE_SIZE*Math.cos(angle);
    double y1 = eye.getY()+SQUARE_SIZE*Math.sin(angle);
    double slope = (y1-eye.getY())/(x1-eye.getX());
    if (Math.cos(angle)==0) {
        if (Math.sin(angle)>0)
            return new R(Double.MAX_VALUE,3*Math.PI/2,BACKGROUND,null);
        else
            return new R(Double.MAX_VALUE,Math.PI/2,BACKGROUND,null);
    }
    if (Math.cos(angle)>0) {
        int firstX = ((eye.getX()/SQUARE_SIZE)+1)*SQUARE_SIZE;
        R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
        for (int x = firstX; x<map[0].length*SQUARE_SIZE; x += SQUARE_SIZE) {
            int y = (int)(slope*(x-eye.getX())+eye.getY());
            if (isOutside(x,y,Color.MAGENTA,this.showRayCastingX)) break;
            Color c = colorAt(x,y);
            int z = heightAt(x,y);
            if (c==null) c = colorAt(x,y-1);
            if (c==null) c = colorAt(x-1,y);
            if (c==null) c = colorAt(x-1,y-1);
            if (z == 0) z = heightAt(x,y-1);
            if (z == 0) z = heightAt(x-1,y);
            if (z == 0) z = heightAt(x-1,y-1);
            if (c!=null) {
                int DX = x-eye.getX();
                double DY = y-eye.getY();
                return new R(Math.sqrt(DX*DX+DY*DY),Math.PI,c,new Plot((int)x,(int)y,(int)z));
            }
        }
        return r;
    } else {
        int firstX = ((eye.getX()/SQUARE_SIZE))*SQUARE_SIZE;
        R r = new R(Double.MAX_VALUE,angle+Math.PI,BACKGROUND,null);
        for (int x = firstX; x>=0; x -= SQUARE_SIZE) {
            int y = (int)(slope*(x-eye.getX())+eye.getY());
            if (isOutside(x,y,Color.MAGENTA,this.showRayCastingX)) break;
            Color c = colorAt(x,y);
            int z = heightAt(x,y);
            if (c==null) c = colorAt(x,y-1);
            if (c==null) c = colorAt(x-1,y);
            if (c==null) c = colorAt(x-1,y-1);
            if (z == 0) z = heightAt(x,y-1);
            if (z == 0) z = heightAt(x-1,y);
            if (z == 0) z = heightAt(x-1,y-1);
            if (c!=null) {
                int DX = x-eye.getX();
                double DY = y-eye.getY();
                return new R(Math.sqrt(DX*DX+DY*DY),0,c,new Plot((int)x,(int)y,(int)z));
            }
        }
        return r;           
    }
}

我应该做一个castRayInZ函数吗?还是我应该将z的值获取其他位置?

最佳答案

因此,您显然知道Wolfenstein raycasting技术的基础。要添加可变高度,您需要执行以下操作:

  • 添加每个单元格的高度信息

    因此,只需在 map 表map[][]中为单元格信息添加另一个值即可。您将这些东西编码为奇数的字符串...
  • 更新扫描线渲染

    在代码中的某个位置(检测到命中之后),您将为每条射线绘制垂直线。在那里,您应该计算出类似的扫描线尺寸(假设y = 0位于屏幕顶部):
    y0 = center_of_view_y + projected_half_size
    y1 = center_of_view_y - projected_half_size
    

    并应更改为:
    y0 = center_of_view_y + projected_size
    y1 = y0 - 2*projected_half_size*wall_size
    

    现在,projected_half_size是为恒定像元高度计算的线大小,wall_size=<0,1>是缩放,center_of_view_y是 View 中水平线的y坐标。这会将您的墙放在地面上。
  • 更新光线转换

    现在,当您碰到第一堵墙时,便会停下来。使用可变的墙高度,只有当您碰到全尺寸的墙(wall_size=1)或用完 map 时,您才能停止。您有2个选项可以实现此目的。
  • 记住所有匹配,并以相反的顺序呈现
  • 立即渲染,但仅从最后渲染的高度而不是从地面渲染。

  • 第一个选项易于实现,但需要更多的内存,并且速度较慢。第二个是快速的,不需要任何列表或堆栈。但这涉及到扫描线渲染的更多数学运算(如果编码正确,则为O(1))

    我从顶部的链接中播放了一些演示。现在结果应如下所示:

    variable height

    如您所见, map 上突出显示的单元格会穿过其高度上方的光线(因此您可以看到它们后面的较大单元格)。

    当您添加移动高度方向(跳跃,楼梯等)时,请当心,然后结束条件必须不同(渲染的扫描线位于 View 顶部)。 y坐标的投影部分也将有所不同,并且需要包括实际的玩家高度。
  • 添加顶部

    您需要添加顶部渲染。它类似于渲染天花板和地板。 IIRC 原先的Wolfenstein没有此功能,但后者伪3D 游戏(例如 DOOM )却没有。

    还有更多类似Perspective Vision on Canvas的方法,但我认为最容易实现(因为我们已经有足够的信息)是在纹理中计算垂直扫描线坐标的顶部部分并仅复制像素。我们已经知道射线照射到细胞的何处,并且还知道播放器/摄像机的角度。有关更多信息,请参见:PCGPE 1.0 Doom techniques

    因此,第一步也要为背面添加点击量。看起来应该像这样:

    back faces

    这是通过首先检查最后一个匹配单元格的匹配来完成的。现在,如果您还记得上次命中(同一条扫描线)的最后一个渲染的y坐标,则如果打了背面而不是渲染该表面,则将最后一个y的顶部颜色渲染为实际的y(或从地板/天花板纹理复制像素) 。这是用于此的绿色:

    top side

  • 如果这有帮助,请使用我的C++(基于GDI/VCL)代码:

    //---------------------------------------------------------------------------
    //--- Doom 3D engine ver: 1.000 --------------------------------------
    //---------------------------------------------------------------------------
    #ifndef _Doom3D_h
    #define _Doom3D_h
    //---------------------------------------------------------------------------
    #include <math.h>
    #include <jpeg.hpp>
    #include "performance.h"
    #include "OpenGLrep4d_double.h"
    //---------------------------------------------------------------------------
    const DWORD _Doom3D_cell_size=10;   // 2D map cell size
    const DWORD _Doom3D_wall_size=100;  // full height of wall in map
    #define _Doom3D_filter_txr
    //---------------------------------------------------------------------------
    class Doom3D
        {
    public:
        DWORD mxs,mys,**pmap;           // 2D map   // txr + height<<16
        DWORD sxs,sys,**pscr;           // pseudo 3D screen
        Graphics::TBitmap *scr;
        DWORD txs,tys,**ptxr,tn;        // 2D textures
        Graphics::TBitmap *txr,*txr2;   // textures, texture mipmaps resolution: /2 and /4
        double plrx,plry,plrz,plra;     // player position [x,y,z,angle]
        double view_ang;                // [rad] view angle
        double focus;                   // [cells] view focal length
        struct _ray
            {
            double x,y,l;               // hit or end of map position
            DWORD hit;                  // map cell of hit or 0xFFFFFFFF
            char typ;                   // H/V
            _ray() {};
            _ray(_ray& a)   { *this=a; }
            ~_ray() {};
            _ray* operator = (const _ray *a) { *this=*a; return this; }
            //_ray* operator = (const _ray &a) { ..copy... return this; }
            };
        _ray *ray;                      // ray[sxs]
    
        keytab keys;
        DWORD txr_sel;
        DWORD cell_h;
    
        Doom3D();
        Doom3D(Doom3D& a)   { *this=a; }
        ~Doom3D();
        Doom3D* operator = (const Doom3D *a) { *this=*a; return this; }
        //Doom3D* operator = (const Doom3D &a) { ..copy... return this; }
    
        void map_resize(DWORD xs,DWORD ys); // change map resolution
        void map_height(DWORD height);      // set height for whole map to convert maps from Wolfenstein3D demo
        void map_clear();                   // clear whole map
        void map_save(AnsiString name);
        void map_load(AnsiString name);
        void scr_resize(DWORD xs,DWORD ys);
        void txr_load(AnsiString name);
    
        void draw();
        void update(double dt);
        void mouse(double x,double y,TShiftState sh)
            {
            x=floor(x/_Doom3D_cell_size); if (x>=mxs) x=mxs-1; if (x<0) x=0;
            y=floor(y/_Doom3D_cell_size); if (y>=mys) y=mys-1; if (y<0) y=0;
            DWORD xx=x,yy=y;
            keys.setm(x,y,sh);
            if (keys.Shift.Contains(ssLeft )) pmap[yy][xx]=(txr_sel)|(cell_h<<16);
            if (keys.Shift.Contains(ssRight)) pmap[yy][xx]=0xFFFFFFFF;
            keys.rfsmouse();
            }
        void wheel(int delta,TShiftState sh)
            {
            if (sh.Contains(ssShift))
                {
                if (delta<0) { cell_h-=10; if (cell_h<10) cell_h=10; }
                if (delta>0) { cell_h+=10; if (cell_h>_Doom3D_wall_size) cell_h=_Doom3D_wall_size; }
                }
            else{
                if (delta<0) { txr_sel--; if (txr_sel==0xFFFFFFFF) txr_sel=tn-1; }
                if (delta>0) { txr_sel++; if (txr_sel==        tn) txr_sel=   0; }
                }
            }
        };
    //---------------------------------------------------------------------------
    Doom3D::Doom3D()
        {
        mxs=0; mys=0;                            pmap=NULL;
        sxs=0; sys=0; scr=new Graphics::TBitmap; pscr=NULL; ray=NULL;
        txs=0; tys=0; txr=new Graphics::TBitmap; ptxr=NULL; tn=0;
                      txr2=new Graphics::TBitmap;
        plrx=0.0; plry=0.0; plrz=0.0; plra=0.0;
        view_ang=60.0*deg;
        focus=0.25;
        txr_sel=0;
        cell_h=_Doom3D_wall_size;
    
        txr_load("textures128x128.jpg");
        map_resize(16,16);
        map_load("Doom3D_map.dat");
        }
    //---------------------------------------------------------------------------
    Doom3D::~Doom3D()
        {
        DWORD y;
        map_save("Doom3D_map.dat");
        if (pmap) { for (y=0;y<mys;y++) delete[] pmap[y]; delete[] pmap; pmap=NULL; } if (ray) delete[] ray; ray=NULL;
        if (pscr) {                                       delete[] pscr; pscr=NULL; } if (scr) delete scr; scr=NULL;
        if (ptxr) {                                       delete[] ptxr; ptxr=NULL; } if (txr) delete txr; txr=NULL;
                                                                                      if (txr2) delete txr2; txr2=NULL;
        }
    //---------------------------------------------------------------------------
    void Doom3D::map_resize(DWORD xs,DWORD ys)
        {
        DWORD y;
        if (pmap) { for (y=0;y<mys;y++) delete[] pmap[y]; delete[] pmap; pmap=NULL; }
        mys=ys; mxs=xs; pmap=new DWORD*[mys]; for (y=0;y<mys;y++) pmap[y]=new DWORD[mxs];
        map_clear();
        plrx=(mxs-1)*0.5; plry=(mys-1)*0.5; plrz=0.0; plra=0.0*deg;
        }
    //---------------------------------------------------------------------------
    void Doom3D::map_height(DWORD h)
        {
        DWORD x,y,c;
        for (y=0;y<mys;y++)
         for (x=0;x<mxs;x++)
            {
            c=pmap[y][x];
            c&=0xFFFF;
            c|=h<<16;
            pmap[y][x]=c;
            }
        }
    //---------------------------------------------------------------------------
    void Doom3D::map_clear()
        {
        DWORD x,y,c;
        for (y=0;y<mys;y++)
         for (x=0;x<mxs;x++)
            {
            c=0xFFFFFFFF;
            if ((x==0)||(x==mxs-1)) c=0;
            if ((y==0)||(y==mys-1)) c=0;
            pmap[y][x]=c;
            }
        }
    //---------------------------------------------------------------------------
    void Doom3D::map_save(AnsiString name)
        {
        int hnd=FileCreate(name); if (hnd<0) return;
        DWORD y;
        y=' PAM';
        FileWrite(hnd,&y  ,4);  // id
        FileWrite(hnd,&mxs,4);  // x resolution
        FileWrite(hnd,&mys,4);  // y resolution
        for (y=0;y<mys;y++)     // map
         FileWrite(hnd,pmap[y],mxs<<2);
        y=' RLP';
        FileWrite(hnd,&y  ,4);  // id
        FileWrite(hnd,&plrx,8);
        FileWrite(hnd,&plry,8);
        FileWrite(hnd,&plrz,8);
        FileWrite(hnd,&plra,8);
        FileClose(hnd);
        }
    //---------------------------------------------------------------------------
    void Doom3D::map_load(AnsiString name)
        {
        int hnd=FileOpen(name,fmOpenRead); if (hnd<0) return;
        DWORD x,y;
        y=' PAM'; FileRead(hnd,&x  ,4); // id
        if (x==y)
            {
            FileRead(hnd,&x,4); // x resolution
            FileRead(hnd,&y,4); // y resolution
            map_resize(x,y);
            for (y=0;y<mys;y++) // map
             FileRead(hnd,pmap[y],mxs<<2);
            }
        y=' RLP'; FileRead(hnd,&x  ,4); // id
        if (x==y)
            {
            FileRead(hnd,&plrx,8);
            FileRead(hnd,&plry,8);
            FileRead(hnd,&plrz,8);
            FileRead(hnd,&plra,8);
            }
        FileClose(hnd);
        }
    //---------------------------------------------------------------------------
    void Doom3D::scr_resize(DWORD xs,DWORD ys)
        {
        scr->HandleType=bmDIB;
        scr->PixelFormat=pf32bit;
        scr->SetSize(xs,ys);
        sxs=scr->Width;
        sys=scr->Height;
        delete[] pscr; pscr=new DWORD*[sys];
        for (DWORD y=0;y<sys;y++) pscr[y]=(DWORD*)scr->ScanLine[y];
        if (ray) delete[] ray; ray=new _ray[sxs];
        }
    //---------------------------------------------------------------------------
    void Doom3D::txr_load(AnsiString name)
        {
        AnsiString ext=ExtractFileExt(name).LowerCase();
        for(;;)
            {
            if (ext==".bmp")
                {
                txr->LoadFromFile(name);
                break;
                }
            if (ext==".jpg")
                {
                TJPEGImage *jpg=new TJPEGImage;
                if (jpg==NULL) return;
                jpg->LoadFromFile(name);
                txr->Assign(jpg);
                delete jpg;
                break;
                }
            return;
            }
        DWORD y=tys;
        txr->HandleType=bmDIB;
        txr->PixelFormat=pf32bit;
        txs=txr->Width;
        tys=txr->Height;
        // mip map
        txr2->SetSize(txs>>1,(tys>>1)+(tys>>2));
        txr2->Canvas->StretchDraw(TRect(0,     0,txs>>1,tys>>1),txr);
        txr2->Canvas->StretchDraw(TRect(0,tys>>1,txs>>2,(tys>>1)+(tys>>2)),txr);
        tn=txs/tys; txs=tys;
        delete[] ptxr; ptxr=new DWORD*[tys];
        for (y=0;y<tys;y++) ptxr[y]=(DWORD*)txr->ScanLine[y];
        }
    //---------------------------------------------------------------------------
    void Doom3D::draw()
        {
        // total time measurement
        tbeg(); double tperf0=performance_tms;
    
        AnsiString tcls,tray,tmap,ttotal;
        double a,a0,da,dx,dy,l,mx,my;
        DWORD x,y,xs2,ys2,c,m;
        double xx0,yy0,dx0,dy0,ll0; DWORD c0,d0;
        double xx1,yy1,dx1,dy1,ll1; DWORD c1,d1;
        _ray *p;
        xs2=sxs>>1;
        ys2=sys>>1;
    
        // aspect ratio,view angle corrections
        a=90.0*deg-view_ang;
        double wall=double(sxs)*(1.25+(0.288*a)+(2.04*a*a)); // [px]
    
        // floor,ceilling/sky
        tbeg();
        for (y=0;y<ys2;y++) for (x=0;x<sxs;x++) pscr[y][x]=0x000080FF;
        for (   ;y<sys;y++) for (x=0;x<sxs;x++) pscr[y][x]=0x00404040;
        tend(); tcls=tstr(1)+" cls";
    
        // [cast rays]
        tbeg();
        // diffuse + ambient lighting
        DWORD ch=155.0+fabs(100.0*sin(plra));
        DWORD cv=155.0+fabs(100.0*cos(plra));
        a0=plra-(0.5*view_ang);
        da=divide(view_ang,sxs-1);
        mx=mxs; my=mys;
        for (p=ray,a=a0,x=0;x<sxs;x++,a+=da,p++)
            {
            p->x=plrx;
            p->y=plry;
            p->hit=0xFFFFFFFF;
            p->typ=' ';
            p->l=1.0e20;
            ll0=ll1=p->l;
            // grid V-line hits
            c0=0; dx0=cos(a);
            if (dx0<0.0) { c0=1; xx0=floor(plrx)-0.001; dx0=-1.0; }
            if (dx0>0.0) { c0=1; xx0=ceil (plrx)+0.001; dx0=+1.0; }
            if (c0) { dy0=tan(a); yy0=plry+((xx0-plrx)*dy0);             dy0*=dx0; dx=xx0-plrx; dy=yy0-plry; ll0=(dx*dx)+(dy*dy); }
            // grid H-line hits
            c1=0; dy1=sin(a);
            if (dy1<0.0) { c1=1; yy1=floor(plry)-0.001; dy1=-1.0; }
            if (dy1>0.0) { c1=1; yy1=ceil (plry)+0.001; dy1=+1.0; }
            if (c1) { dx1=divide(1.0,tan(a)); xx1=plrx+((yy1-plry)*dx1); dx1*=dy1; dx=xx1-plrx; dy=yy1-plry; ll1=(dx*dx)+(dy*dy); }
            int height0=sys; // already rendered height [pixels]
            bool _hit,_back=false,_bck=true;
            if (!c0) ll0=1e20;
            if (!c1) ll1=1e20;
            for (;c0||c1;)
                {
                _hit=false;
                // grid V-line hits
                if (c0)
                    {
                    if (xx0<0.0) { c0=0; ll0=1e20; }
                    if (xx0>=mx) { c0=0; ll0=1e20; }
                    if (yy0<0.0) { c0=0; ll0=1e20; }
                    if (yy0>=my) { c0=0; ll0=1e20; }
                    }
                if ((c0)&&(ll0<ll1))
                    {
                    m=DWORD(xx0-dx0);
                    if ((m>=0.0)&&(m<mxs)&&(!_bck)){ c=pmap[DWORD(yy0)][      m   ]; if ((c&0xFFFF)!=0xFFFF) { p->hit=c; p->typ='V'; p->l=ll0; p->x=xx0; p->y=yy0; _hit=true; _back=true;  _bck=true;  }}
                    if (!_hit)                     { c=pmap[DWORD(yy0)][DWORD(xx0)]; if ((c&0xFFFF)!=0xFFFF) { p->hit=c; p->typ='V'; p->l=ll0; p->x=xx0; p->y=yy0; _hit=true; _back=false; _bck=false; } xx0+=dx0; dx=xx0-plrx; yy0+=dy0; dy=yy0-plry; ll0=(dx*dx)+(dy*dy); }
                    }
                // grid H-line hits
                if (c1)
                    {
                    if (xx1<0.0) { c1=0; ll1=1e20; }
                    if (xx1>=mx) { c1=0; ll1=1e20; }
                    if (yy1<0.0) { c1=0; ll1=1e20; }
                    if (yy1>=my) { c1=0; ll1=1e20; }
                    }
                if ((c1)&&(ll0>ll1)&&(!_hit))
                    {
                    m=DWORD(yy1-dy1);
                    if ((m>=0.0)&&(m<mys)&&(!_bck)){ c=pmap[      m   ][DWORD(xx1)]; if ((c&0xFFFF)!=0xFFFF) { p->hit=c; p->typ='H'; p->l=ll1; p->x=xx1; p->y=yy1; _hit=true; _back=true;  _bck=true;  }}
                    if (!_hit)                     { c=pmap[DWORD(yy1)][DWORD(xx1)]; if ((c&0xFFFF)!=0xFFFF) { p->hit=c; p->typ='H'; p->l=ll1; p->x=xx1; p->y=yy1; _hit=true; _back=false; _bck=false; } xx1+=dx1; dx=xx1-plrx; yy1+=dy1; dy=yy1-plry; ll1=(dx*dx)+(dy*dy); }
                    }
                // render scan line
                if (_hit)
                    {
                    union { DWORD dd; BYTE db[4]; } cc;
                    int tx,ty,sy,sy0,sy1,cnt,dsy,dty;
                    p->l=sqrt(p->l)*cos(a-plra);// anti fish eye
                    m=divide(wall*focus,p->l);  // projected wall half size
                    c=0;
                    if (p->typ=='H') { c=ch; tx=double(double(txs)*(p->x-floor(p->x))); }
                    if (p->typ=='V') { c=cv; tx=double(double(txs)*(p->y-floor(p->y))); }
                    tx+=txs*(p->hit&0xFFFF);
    
                    // prepare interpolation
                    sy1=ys2+m;
    //              sy0=ys2-m;                                          // constant wall height
                    sy0=sy1-(((m+m)*(p->hit>>16))/_Doom3D_wall_size);   // variable wall height
                    dty=tys-1;
                    dsy=sy1-sy0+1;
                    // skip sy>=sys
                    if (sy1>=sys) sy1=sys-1;
                    // skip sy<0
                    for (cnt=dsy,sy=sy0,ty=0;sy<0;sy++) { cnt-=dty; while (cnt<=0) { cnt+=dsy; ty++; }}
    
                    #ifdef _Doom3D_filter_txr
                    DWORD r=0,g=0,b=0,n=0;
                    #else
                    cc.dd=ptxr[ty][tx];
                    cc.db[0]=DWORD((DWORD(cc.db[0])*c)>>8);
                    cc.db[1]=DWORD((DWORD(cc.db[1])*c)>>8);
                    cc.db[2]=DWORD((DWORD(cc.db[2])*c)>>8);
                    #endif
                    // continue sy>=0
                    y=height0;
                    if (sy1>height0) sy1=height0;
                    if (sy0<height0) height0=sy0;
                    if (_back){ for (sy=sy0;sy<=y;sy++){ if ((sy>0)&&(sy<sys)) pscr[sy][x]=0x0000FF00; }}
                     else for (;sy<=sy1;sy++)
                        {
                        #ifdef _Doom3D_filter_txr
                        if (!n)
                            {
                            cc.dd=ptxr[ty][tx];
                            b+=DWORD(cc.db[0]);
                            g+=DWORD(cc.db[1]);
                            r+=DWORD(cc.db[2]); n+=256;
                            }
                        if ((sy>0)&&(sy<sys))
                            {
                            cc.db[0]=DWORD(c*b/n); b=0;
                            cc.db[1]=DWORD(c*g/n); g=0;
                            cc.db[2]=DWORD(c*r/n); r=0; n=0;
                            pscr[sy][x]=cc.dd;
                            }
                        cnt-=dty; while (cnt<=0)
                            {
                            cnt+=dsy; ty++;
                            cc.dd=ptxr[ty][tx];
                            b+=DWORD(cc.db[0]);
                            g+=DWORD(cc.db[1]);
                            r+=DWORD(cc.db[2]); n+=256;
                            }
                        #else
                        if ((sy>0)&&(sy<sys)) pscr[sy][x]=cc.dd;
                        cnt-=dty; while (cnt<=0)
                            {
                            cnt+=dsy; ty++;
                            cc.dd=ptxr[ty][tx];
                            cc.db[0]=DWORD((DWORD(cc.db[0])*c)>>8);
                            cc.db[1]=DWORD((DWORD(cc.db[1])*c)>>8);
                            cc.db[2]=DWORD((DWORD(cc.db[2])*c)>>8);
                            }
                        #endif
                        }
                    if (height0<0) break;
                    }
                }
            }
        tend(); tray=tstr(1)+" ray";
    
        // [2D map]
        tbeg();
        m=_Doom3D_cell_size;
        mx=_Doom3D_cell_size;
        if ((sxs>=mxs*m)&&(sys>=mys*m))
            {
            for (y=0;y<mys*m;y++)       // pmap[][]
             for (x=0;x<mxs*m;x++)
                {
                if ((pmap[y/m][x/m]&0xFFFF)!=0xFFFF) c=0x00808080; else c=0x00000000;
                pscr[y][x]=c;
                }
            x=double(plrx*mx);          // view rays
            y=double(plry*mx);
            scr->Canvas->Pen->Color=0x00005050;
            scr->Canvas->Pen->Mode=pmMerge;
            for (c=0;c<sxs;c++)
                {
                scr->Canvas->MoveTo(x,y);
                scr->Canvas->LineTo(DWORD(ray[c].x*mx),DWORD(ray[c].y*mx));
                }
            scr->Canvas->Pen->Mode=pmCopy;
            c=focus*m;                  // player and view direction
            scr->Canvas->Pen->Color=0x000000FF;
            scr->Canvas->Brush->Color=0x000000FF;
            scr->Canvas->MoveTo(x,y);
            scr->Canvas->LineTo(DWORD(ray[xs2].x*mx),DWORD(ray[xs2].y*mx));
            scr->Canvas->Ellipse(x-c,y-c,x+c,y+c);
            scr->Canvas->Pen->Color=0x00202020;
            for (y=0;y<=mys;y++)        // map grid
             for (x=0;x<=mxs;x++)
                {
                scr->Canvas->MoveTo(0    ,y*m);
                scr->Canvas->LineTo(mxs*m,y*m);
                scr->Canvas->MoveTo(x*m,    0);
                scr->Canvas->LineTo(x*m,mys*m);
                }
            x=keys.mx*m;                // selected cell
            y=keys.my*m;
            scr->Canvas->Pen->Color=0x0020FFFF;
            scr->Canvas->MoveTo(x  ,y  );
            scr->Canvas->LineTo(x+m,y  );
            scr->Canvas->LineTo(x+m,y+m);
            scr->Canvas->LineTo(x  ,y+m);
            scr->Canvas->LineTo(x  ,y  );
            }
        tend(); tmap=tstr(1)+" map";
    
        // [editor]
        if (txr_sel!=0xFFFFFFFF)
            {
            int x=sxs,y=5,s0,s1,s2,i,j;
            s0=txs>>1;
            s1=txs>>2;
            s2=(s0*cell_h)/_Doom3D_wall_size;
    
            for (i=-3;i<=3;i++)
                {
                j=txr_sel+i;
                while (j<  0) j+=tn;
                while (j>=tn) j-=tn;
                if (i) { scr->Canvas->CopyRect(TRect(x-s1,y+(s1>>1),x,s1+(s1>>1)),txr2->Canvas,TRect(s1*j,s0,s1*j+s1,s0+s1)); x-=s1+5; }
                else   { scr->Canvas->CopyRect(TRect(x-s0,y+s0-s2  ,x,s0        ),txr2->Canvas,TRect(s0*j, 0,s0*j+s0,s2   )); x-=s0+5; }
                }
            }
    
        // total time measurement
        performance_tms=tperf0;
        tend(); ttotal=tstr(1)+" total";
    
        x=m*mxs+m;
        c=16; y=-c;
        scr->Canvas->Font->Color=clYellow;
        scr->Canvas->Brush->Style=bsClear;
        scr->Canvas->TextOutA(x,y+=c,AnsiString().sprintf("player: %.2lf x %.2lf x %.2lf",plrx,plry,plrz));
        scr->Canvas->TextOutA(x,y+=c,AnsiString().sprintf(" mouse: %.2lf x %.2lf",keys.mx,keys.my));
        scr->Canvas->TextOutA(x,y+=c,tray);
        scr->Canvas->TextOutA(x,y+=c,tcls);
        scr->Canvas->TextOutA(x,y+=c,tmap);
        scr->Canvas->TextOutA(x,y+=c,ttotal);
        scr->Canvas->TextOutA(x,y+=c,AnsiString().sprintf("   key: %d",keys.Key));
    
        // aspect ratio test
    /*
        c=ys2*7/10;
        scr->Canvas->Rectangle(xs2-c,ys2-c,xs2+c,ys2+c);
    */
        // cross
        c=4,m=32;
        scr->Canvas->Pen->Color=clRed;
        scr->Canvas->MoveTo(xs2-c,ys2-m);
        scr->Canvas->LineTo(xs2-c,ys2-c);
        scr->Canvas->LineTo(xs2-m,ys2-c);
        scr->Canvas->MoveTo(xs2+c,ys2-m);
        scr->Canvas->LineTo(xs2+c,ys2-c);
        scr->Canvas->LineTo(xs2+m,ys2-c);
        scr->Canvas->MoveTo(xs2-c,ys2+m);
        scr->Canvas->LineTo(xs2-c,ys2+c);
        scr->Canvas->LineTo(xs2-m,ys2+c);
        scr->Canvas->MoveTo(xs2+c,ys2+m);
        scr->Canvas->LineTo(xs2+c,ys2+c);
        scr->Canvas->LineTo(xs2+m,ys2+c);
    
        scr->Canvas->Brush->Style=bsSolid;
        }
    //---------------------------------------------------------------------------
    void Doom3D::update(double dt)
        {
        int move=0;
        double da=120.0*deg*dt;
        double dl=  5.0    *dt;
        double dx=0.0,dy=0.0,dz=0.0;
        if (keys.get(104)) { plra-=da; if (plra< 0.0) plra+=pi2; }                      // turn l/r
        if (keys.get(105)) { plra+=da; if (plra>=pi2) plra-=pi2; }
        if (keys.get(101)) { move=1; dx=+dl*cos(plra); dy=+dl*sin(plra); }              // move f/b
        if (keys.get( 98)) { move=1; dx=-dl*cos(plra); dy=-dl*sin(plra); }
        if (keys.get(102)) { move=1; dx= dl*cos(plra-90*deg); dy=dl*sin(plra-90*deg); } // strafe l/r
        if (keys.get( 99)) { move=1; dx= dl*cos(plra+90*deg); dy=dl*sin(plra+90*deg); }
        if (keys.get(100)) { move=1; dz=+dl; }  // strafe u/d
        if (keys.get( 97)) { move=1; dz=-dl; }
        if (move)   // update/test plr position
            {
            double x,y,z,mx,my;
            x=plrx+dx; mx=mxs-focus;
            y=plry+dy; my=mys-focus;
            z=plrz+dz; if ((z>=0.0)&&(z<=_Doom3D_wall_size)) plrz=z;;
            if (x<focus) x=focus; if (x>mx) x=mx;
            if (y<focus) y=focus; if (y>my) y=my;
            dx*=divide(focus,dl);
            dy*=divide(focus,dl);
                 if ((pmap[DWORD(y+dy)][DWORD(x+dx)]&0xFFFF)==0xFFFF) { plrx=x; plry=y; }
            else if ((pmap[DWORD(y+dy)][DWORD(x   )]&0xFFFF)==0xFFFF)           plry=y;
            else if ((pmap[DWORD(y   )][DWORD(x+dx)]&0xFFFF)==0xFFFF)   plrx=x;
            }
        keys.rfskey();
        }
    //---------------------------------------------------------------------------
    //---------------------------------------------------------------------------
    #endif
    //---------------------------------------------------------------------------
    //---------------------------------------------------------------------------
    

    只需忽略performance.h时间测量tbeg,tend,tstrOpenGLrep4d_double.h键盘和鼠标处理程序keytab以及与端口VCL相关的内容(Canvas,AnsiString,文件访问,JPEG ...)。

    如果您需要帮助以了解gfx内容,请参见
  • Display an array of color in C

  • 该类的用法很简单,即声明该类的一个对象,然后将该事件添加到您的窗口中(鼠标,键盘,重绘...)。我的VCL窗口(带有一个计时器的单一表单)代码如下所示:

    //$$---- Form CPP ----
    //---------------------------------------------------------------------------
    #include <vcl.h>
    #pragma hdrstop
    #include "win_main.h"
    #include "Doom3D.h"
    //---------------------------------------------------------------------------
    #pragma package(smart_init)
    #pragma resource "*.dfm"
    TMain *Main;
    Doom3D game;
    //---------------------------------------------------------------------------
    void TMain::draw()
        {
        game.draw();
        Canvas->Draw(0,0,game.scr);
        }
    //---------------------------------------------------------------------------
    __fastcall TMain::TMain(TComponent* Owner) : TForm(Owner)
        {
        }
    //---------------------------------------------------------------------------
    void __fastcall TMain::FormResize(TObject *Sender)
        {
        game.scr_resize(ClientWidth,ClientHeight);
        }
    //---------------------------------------------------------------------------
    void __fastcall TMain::tim_redrawTimer(TObject *Sender)
        {
        game.update(tim_redraw->Interval*0.001);
        draw();
        }
    //---------------------------------------------------------------------------
    void __fastcall TMain::FormKeyDown(TObject *Sender, WORD &Key,TShiftState Shift){ game.keys.set(Key,Shift); }
    void __fastcall TMain::FormKeyUp(TObject *Sender, WORD &Key, TShiftState Shift) { game.keys.rst(Key,Shift); }
    void __fastcall TMain::FormActivate(TObject *Sender)                            { game.keys.reset_keys(); }
    //---------------------------------------------------------------------------
    void __fastcall TMain::FormMouseMove(TObject *Sender,                      TShiftState Shift, int X, int Y) { game.mouse(X,Y,Shift); }
    void __fastcall TMain::FormMouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift, int X, int Y) { game.mouse(X,Y,Shift); }
    void __fastcall TMain::FormMouseUp  (TObject *Sender, TMouseButton Button, TShiftState Shift, int X, int Y) { game.mouse(X,Y,Shift); }
    void __fastcall TMain::FormMouseWheel(TObject *Sender, TShiftState Shift, int WheelDelta, TPoint &MousePos, bool &Handled) { game.wheel(WheelDelta,Shift); Handled=true; }
    //---------------------------------------------------------------------------
    

    这里是主要的迭代变量说明:

    variables

    这是纹理文件:

    textures

    经过一些代码调整和perspective correct texture mapping之后,它看起来是这样的:

    jump

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