## FPS_Sample

version 1.0.0 (2.87 KB) by
How to create FPS by MATLAB

Updated Mon, 16 May 2022 07:53:47 +0000

If you want to change the wall, you can change pos_wall parameter.
function test_FPS
clear,clc,close all;
m=200;
% Wall Samples
% pos_wall = [50 50; 100 300; 250 200; 50 50]+100;
p = nsidedpoly(50, 'Center', [200 200], 'Radius', 100);
pos_wall = [p.Vertices;p.Vertices(1,:)];
% Player 1st position
player.pos = [10,10];
player.angle = 45;
Angle = 30;
dAngle = 10;
n = 21;
% Generate an arc and line segments
th = deg2rad(linspace(player.angle - Angle,player.angle + Angle,n))';
r = 100;
v = r.*[cos(th),sin(th)];
p2 = v + player.pos;
% Intersection calculation(1st step)
% Mapping Toolbox --> polyxpoly
% Free： https://jp.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections
x = reshape(([repelem(player.pos(1),height(p2))',p2(:,1),nan(height(p2),1) ])',[],1);
y = reshape(([repelem(player.pos(2),height(p2))',p2(:,2),nan(height(p2),1) ])',[],1);
[xi,yi,kk] = polyxpoly(x,y,pos_wall(:,1),pos_wall(:,2));
% Wall for Bird's eye view
Wallx = (1:height(p2))';
% Calculate only in front
dummy = Wallx.*(4-1) + 1;
dummy = [1 ; dummy(1:end-1)];
Wally = nan(height(p2),1);
K = 3; % Fix parameter: 4-1
%% Plot
%% 1. Bird's eye view
f = figure('Color','#AAAAAA');
ax = axes('Color','#AAAAAA');
ax.Title.String = "Bird's eye view";
text(350,350,["r:ClockWise";"e:CounterClockWise";"a:ZoomIn";"s:ZoomOut"]);
axis off
hold on
% Wall
wall = fill(ax,pos_wall(:,1),pos_wall(:,2),'k',LineStyle='none');
axis equal
ax.XLim = [0 400];
ax.YLim = [0 400];
% Player1: Position
pl = plot(ax,player.pos(1), player.pos(2),'o', ...
MarkerFaceColor='y',MarkerEdgeColor='none',...
MarkerSize=5);
% Player2: Arc
pl1 = plot(ax,p2(:,1),p2(:,2),'LineStyle','-', ...
'LineWidth',1,'Color','y');
% Player3: Line segments
for ii = 1:height(p2)
pl2(ii) = plot(ax,[player.pos(1);p2(ii,1)],...
[player.pos(2); p2(ii,2)],'LineStyle','--', ...
'LineWidth',1,'Color','y');
end
tmp1 = [xi;nan(height(p2)-length(xi),1)]';
tmp2 = [yi;nan(height(p2)-length(yi),1)]';
% Collision detection
pl3 = plot(ax,tmp1,tmp2,'o', ...
LineStyle='none', ...
MarkerFaceColor='r',MarkerEdgeColor='none',...
MarkerSize=5);
hold off
%% 2. First person perspective
f_FPS = figure('Color','#AAAAAA');
ax_FPS = axes('Color','#AAAAAA');
ax_FPS.Title.String = "First person perspective";
hold on
pl_FPS_p = stem(ax_FPS,-Wallx,Wally./2,'Marker','none','LineWidth',round(m/n),'Color','w');
pl_FPS_n = stem(ax_FPS,-Wallx,-Wally./2,'Marker','none','LineWidth',round(m/n),'Color','w');
ax_FPS.XLim = [-(height(Wallx)+1) 0];
% Wall Max Height
ax_FPS.YLim = [-1 1].*K*2;
% Visualise
ax_FPS.XTick = [];
ax_FPS.YTick = [];
ax_FPS.XAxis.Color = 'none';
ax_FPS.YAxis.Color = 'none';
hold off
%% Trigger
f.WindowButtonDownFcn = @motion;
f.WindowButtonUpFcn = @motion;
f.KeyPressFcn = @rotation;
%% Nested function
%% Rotation
function rotation(src,data,eventdata)
if strcmp(data.Key,'r')
elseif strcmp(data.Key,'e')
end
if strcmp(data.Key,'a')
r = r + 10;
elseif strcmp(data.Key,'s')
r = r - 10;
end
v = r*[cos(th),sin(th)];
movepoint;
end
%% Mouse Click
function motion(src,data,eventdata)
if strcmp(data.EventName,'WindowMousePress')
f.WindowButtonMotionFcn = @movepoint;
else
f.WindowButtonMotionFcn = '';
end
end
%% Position update
function movepoint(src,data)
pos = get(gca,'CurrentPoint');
pl.XData = pos(1,1);
pl.YData = pos(1,2);
pl1.XData = v(:,1) + pl.XData;
pl1.YData = v(:,2) + pl.YData;
player.pos = pos(1,1:2);
p2 = [pl1.XData; pl1.YData]';
Cross;
for ii = 1:length(pl2)
pl2(ii).XData = [0, v(ii,1)] + pl.XData;
pl2(ii).YData = [0, v(ii,2)] + pl.YData;
end
end
%% Collision detection
function Cross
x = reshape(([repelem(player.pos(1),height(p2))',p2(:,1),nan(height(p2),1) ])',[],1);
y = reshape(([repelem(player.pos(2),height(p2))',p2(:,2),nan(height(p2),1) ])',[],1);
[xi,yi,kk] = polyxpoly(x,y,pos_wall(:,1),pos_wall(:,2));
% Vector from plyer to cross point
tmp = [xi,yi] - player.pos;
% extract more closer point when line segment has 2 cross points
tmp = [xi, yi, (tmp(:,1).^2+tmp(:,2).^2), kk(:,1), false(length(xi),1)];
t1 = unique(tmp(:,4));
for jj = 1:length(t1)
MIN_tmp = min(tmp(tmp(:,4) == t1(jj),3));
tmp( (tmp(:,4)==t1(jj)) & (tmp(:,3)==MIN_tmp) ,end) = true;
end
% point y
idx = tmp(:,end)==true;
% extract xi and yi
tmp = tmp(idx,[1:4]);
[~,I] = sort(tmp(:,4));
tmp = tmp(I,:);
xi = tmp(:,1);
yi = tmp(:,2);
idx2 = ismember(dummy,tmp(:,4));
Wallx = (1:height(p2))';
Wally = nan(height(p2),1);
Wally(find(idx2)) = sqrt(tmp(:,3)./r.^2); %norm length
Wally = Wally.*cos(th2);
pl_FPS_p.YData = K./Wally./2;
pl_FPS_n.YData = -K./Wally./2;
pl3.XData = [xi;nan(height(p2)-length(xi),1)]';
pl3.YData = [yi;nan(height(p2)-length(yi),1)]';
end
end

### Cite As

Hernia Baby (2022). FPS_Sample (https://www.mathworks.com/matlabcentral/fileexchange/111640-fps_sample), MATLAB Central File Exchange. Retrieved .

##### MATLAB Release Compatibility
Created with R2022a
Compatible with any release
##### Platform Compatibility
Windows macOS Linux