First cut at a replica of the python raycaster. Left side almost works the same but have to sort out math differences.
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Zed A. Shaw
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21 changed files with 2165 additions and 90 deletions
250
scratchpad/raycaster_flat.cpp
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250
scratchpad/raycaster_flat.cpp
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/*
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Copyright (c) 2004-2021, Lode Vandevenne
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All rights reserved.
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Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <cmath>
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#include <string>
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#include <vector>
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#include <iostream>
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#include "quickcg.h"
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using namespace QuickCG;
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/*
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g++ *.cpp -lSDL -O3 -W -Wall -ansi -pedantic
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g++ *.cpp -lSDL
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*/
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//place the example code below here:
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#define screenWidth 640
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#define screenHeight 480
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#define mapWidth 24
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#define mapHeight 24
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int worldMap[mapWidth][mapHeight]=
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{
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{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,2,2,2,2,2,0,0,0,0,3,0,3,0,3,0,0,0,1},
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{1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,3,0,0,0,3,0,0,0,1},
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{1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,2,2,0,2,2,0,0,0,0,3,0,3,0,3,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,0,0,0,0,5,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,0,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
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{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}
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};
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int main(int /*argc*/, char */*argv*/[])
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{
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double posX = 22, posY = 12; //x and y start position
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double dirX = -1, dirY = 0; //initial direction vector
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double planeX = 0, planeY = 0.66; //the 2d raycaster version of camera plane
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double time = 0; //time of current frame
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double oldTime = 0; //time of previous frame
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screen(screenWidth, screenHeight, 0, "Raycaster");
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while(!done())
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{
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for(int x = 0; x < w; x++)
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{
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//calculate ray position and direction
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double cameraX = 2 * x / (double)w - 1; //x-coordinate in camera space
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double rayDirX = dirX + planeX * cameraX;
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double rayDirY = dirY + planeY * cameraX;
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//which box of the map we're in
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int mapX = int(posX);
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int mapY = int(posY);
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//length of ray from current position to next x or y-side
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double sideDistX;
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double sideDistY;
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//length of ray from one x or y-side to next x or y-side
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//these are derived as:
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//deltaDistX = sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX))
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//deltaDistY = sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY))
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//which can be simplified to abs(|rayDir| / rayDirX) and abs(|rayDir| / rayDirY)
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//where |rayDir| is the length of the vector (rayDirX, rayDirY). Its length,
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//unlike (dirX, dirY) is not 1, however this does not matter, only the
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//ratio between deltaDistX and deltaDistY matters, due to the way the DDA
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//stepping further below works. So the values can be computed as below.
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// Division through zero is prevented, even though technically that's not
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// needed in C++ with IEEE 754 floating point values.
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double deltaDistX = (rayDirX == 0) ? 1e30 : std::abs(1 / rayDirX);
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double deltaDistY = (rayDirY == 0) ? 1e30 : std::abs(1 / rayDirY);
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double perpWallDist;
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//what direction to step in x or y-direction (either +1 or -1)
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int stepX;
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int stepY;
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int hit = 0; //was there a wall hit?
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int side; //was a NS or a EW wall hit?
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//calculate step and initial sideDist
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if(rayDirX < 0)
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{
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stepX = -1;
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sideDistX = (posX - mapX) * deltaDistX;
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}
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else
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{
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stepX = 1;
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sideDistX = (mapX + 1.0 - posX) * deltaDistX;
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}
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if(rayDirY < 0)
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{
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stepY = -1;
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sideDistY = (posY - mapY) * deltaDistY;
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}
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else
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{
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stepY = 1;
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sideDistY = (mapY + 1.0 - posY) * deltaDistY;
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}
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//perform DDA
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while(hit == 0)
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{
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//jump to next map square, either in x-direction, or in y-direction
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if(sideDistX < sideDistY)
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{
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sideDistX += deltaDistX;
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mapX += stepX;
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side = 0;
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}
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else
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{
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sideDistY += deltaDistY;
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mapY += stepY;
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side = 1;
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}
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//Check if ray has hit a wall
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if(worldMap[mapX][mapY] > 0) hit = 1;
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}
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//Calculate distance projected on camera direction. This is the shortest distance from the point where the wall is
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//hit to the camera plane. Euclidean to center camera point would give fisheye effect!
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//This can be computed as (mapX - posX + (1 - stepX) / 2) / rayDirX for side == 0, or same formula with Y
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//for size == 1, but can be simplified to the code below thanks to how sideDist and deltaDist are computed:
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//because they were left scaled to |rayDir|. sideDist is the entire length of the ray above after the multiple
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//steps, but we subtract deltaDist once because one step more into the wall was taken above.
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if(side == 0) perpWallDist = (sideDistX - deltaDistX);
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else perpWallDist = (sideDistY - deltaDistY);
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//Calculate height of line to draw on screen
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int lineHeight = (int)(h / perpWallDist);
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//calculate lowest and highest pixel to fill in current stripe
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int drawStart = -lineHeight / 2 + h / 2;
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if(drawStart < 0) drawStart = 0;
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int drawEnd = lineHeight / 2 + h / 2;
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if(drawEnd >= h) drawEnd = h - 1;
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//choose wall color
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ColorRGBA color;
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switch(worldMap[mapX][mapY])
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{
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case 1: color = RGB_Red; break; //red
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case 2: color = RGB_Green; break; //green
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case 3: color = RGB_Blue; break; //blue
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case 4: color = RGB_White; break; //white
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default: color = RGB_Yellow; break; //yellow
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}
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//give x and y sides different brightness
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if(side == 1) {color = color / 2;}
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//draw the pixels of the stripe as a vertical line
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verLine(x, drawStart, drawEnd, color);
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}
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//timing for input and FPS counter
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oldTime = time;
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time = getTicks();
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double frameTime = (time - oldTime) / 1000.0; //frameTime is the time this frame has taken, in seconds
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print(1.0 / frameTime); //FPS counter
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redraw();
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//speed modifiers
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double moveSpeed = frameTime * 5.0; //the constant value is in squares/second
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double rotSpeed = frameTime * 3.0; //the constant value is in radians/second
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SDL_Event event;
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while(SDL_PollEvent(&event)) {
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if(event.type != SDL_KEYDOWN) continue;
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cls();
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//move forward if no wall in front of you
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if(event.key.keysym.sym == SDLK_UP)
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{
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if(worldMap[int(posX + dirX * moveSpeed)][int(posY)] == false) posX += dirX * moveSpeed;
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if(worldMap[int(posX)][int(posY + dirY * moveSpeed)] == false) posY += dirY * moveSpeed;
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}
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//move backwards if no wall behind you
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if(event.key.keysym.sym == SDLK_DOWN)
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{
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if(worldMap[int(posX - dirX * moveSpeed)][int(posY)] == false) posX -= dirX * moveSpeed;
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if(worldMap[int(posX)][int(posY - dirY * moveSpeed)] == false) posY -= dirY * moveSpeed;
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}
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//rotate to the right
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if(event.key.keysym.sym == SDLK_RIGHT)
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{
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//both camera direction and camera plane must be rotated
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double oldDirX = dirX;
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dirX = dirX * cos(-rotSpeed) - dirY * sin(-rotSpeed);
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dirY = oldDirX * sin(-rotSpeed) + dirY * cos(-rotSpeed);
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double oldPlaneX = planeX;
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planeX = planeX * cos(-rotSpeed) - planeY * sin(-rotSpeed);
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planeY = oldPlaneX * sin(-rotSpeed) + planeY * cos(-rotSpeed);
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}
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//rotate to the left
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if(event.key.keysym.sym == SDLK_LEFT)
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{
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//both camera direction and camera plane must be rotated
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double oldDirX = dirX;
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dirX = dirX * cos(rotSpeed) - dirY * sin(rotSpeed);
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dirY = oldDirX * sin(rotSpeed) + dirY * cos(rotSpeed);
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double oldPlaneX = planeX;
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planeX = planeX * cos(rotSpeed) - planeY * sin(rotSpeed);
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planeY = oldPlaneX * sin(rotSpeed) + planeY * cos(rotSpeed);
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}
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}
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}
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return 0;
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}
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