Thread: Help creating a random point that moves

  1. #1
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    Help creating a random point that moves

    I have an assignment that involves creating a simple game. My game is sort of similar to the game snake, in that the purpose is to collect objects, in this case that moves in a random direction.

    using: K.I.S.S programming

    My issue and what I need help with is creating the array, filling it with random points, and then implementing a way to make it move (I think)

    What it does now is create a point that moves crazy fast and without a pattern.

    Line 33-45 is the function I need help with.

    My code:
    insert
    Code:
    #include <stdio.h>
    #include <kiss-graphics.h>
    #include <kiss-compat.h>
    #include <kiss-input.h>
    
    void drawRobot(int x0, int y0,float a, float s);
    void drawbackground();
    void drawtarget();
    
    int main() 
    {
        int x=400,y=400,i,a,size;//start in middle
        graphics_init(800,800);
        
        graphics_update();
        while((x <= 800)&&(y > 0)&&(x > 0)&&(y <= 800)){// loop until Q key is pressed
            drawbackground();
            if(left_button()!=0){x=x- 4;} // if left is pressed move left a pixel
            if(right_button()!=0){x=x+4;}// if right, move to the right
            if(up_button()!=0){y=y-4;}// if up is pressed move up (smaller Y)
            if(down_button()!=0){y=y+4;}// if down is pressed move down
            drawRobot(x,y,0,0);
            drawtarget();
            graphics_update();// update the screen
        }
        
        
        
        sleep(5);
        return 0;
    }
    //This is the function
    void drawtarget(double xA[], double yA[], int aSize)
    {
        int x,y;
        int a[1000],b[1000],size=1000,i;// create an array and other int variables
        //for(i=0;i<10;i++){
            a[i]=rand()%700;
            b[i]=rand()%700;
            x=a[3];
            y=a[4];
            graphics_circle_fill(x,y,10,5,5,5);
            graphics_update();    
            }
        
    void drawbackground()
    {
        
        
        graphics_fill(0,180,0);// fill in background
        graphics_update();
    }
    
    
    void drawRobot(int x, int y,float a, float s)
    {
        graphics_circle_fill(x+5,y+10,10,5,5,5);//Robot
        graphics_line(x+50, y+50, x-5, y-5, 0, 0, 0);
    }
    Thank you guys, in advance for helping. Any pointers and advice would be great.
    Last edited by Human107; 12-10-2012 at 03:08 PM.

  2. #2
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    Quote Originally Posted by Human107 View Post
    My issue and what I need help with is creating the array, filling it with random points, and then implementing a way to make it move (I think)

    What it does now is create a point that moves crazy fast and without a pattern.
    If you want to move the object randomly, you need to calculate a random direction (probably either up, down, left or right) and then move the object accordingly.

    Bye, Andreas

  3. #3
    TEIAM - problem solved
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    Melbourne Australia
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    rand (CRT)

    You are missing srand
    Fact - Beethoven wrote his first symphony in C

  4. #4
    TEIAM - problem solved
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    Oh, and stdlib.h for the random function
    Fact - Beethoven wrote his first symphony in C

  5. #5
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    First a tip on some English for your KISS website:
    Were a mod_ PERL programming house. and no. we don't do POOP (Perl Object Orientated Programming). We use a object orientated style with out <correct is "without"> the OOPs it self. <wrong words, correct is "itself">

    There are a number of reasons why. <replace the period with a comma> but simply put.. We don't

    We do how ever <correct word is "however"> like using gagets, <correct is "gadgets"> widgets and javascript, Ajax, DHTML and CSS.
    And here's a program to help with your timing of the movement. The ascii robot starts out fast, but slows as it moves along.

    Code:
    
    /*ASCII robot animation */
    
    #include <stdio.h>
    #include <conio.h>
    #include <time.h>
    #include <windows.h>
    
    #define VMAX 3
    #define HMAX 3
    
    void printRobot(char robot[][3],int x, int y);
    void fillIn(int x,int y); 
    
    int main(void) {
       int i,x,y;
       clock_t pause = 15;
       //clock_t timerNew,timerOld;
       char robot[VMAX][HMAX]={
          {'.','o','.'},
          {'-','¦','-'},
          {'/',' ','\\'}
          };
    
       printf("Say I want this 'robot', to get animated, but slow down as he travels\n\n");
    
       for(i=0;i<304;i++)
          printf("%c%c%c%c%c",'.','.','.','.','.');
    
       x=2;y=6;
       
       for(i=0;i<108;i++) {
          _gotoxy(x,y);
          printRobot(robot,x,y);
       
          Sleep(pause);
       
          fillIn(x,y);
          x+=1;  
          if(x>75){
             x=2;
             y+=VMAX;
          }
          if(i>95) {
             ++y;
             pause+=4;
          }
          pause+=3;
       }
       x+=10; y+=VMAX;
       _gotoxy(x,y);
       printRobot(robot,x,y);
       _gotoxy(1,23);
       printf("\n");
       return 0;
    }
    void printRobot(char robot[][3],int x, int y) {
       int r,c;
       
       for(c=0,r=2;c<HMAX;c++) 
          printf("%c",robot[r][c]);
       _gotoxy(x,y-1);
       for(c=0,r=1;c<HMAX;c++)   
          printf("%c",robot[r][c]);
       _gotoxy(x,y-2);
       for(c=0,r=0;c<HMAX;c++)
          printf("%c",robot[r][c]);
    }
    void fillIn(int x,int y) {
       int i;
       for(i=VMAX;i>-1;i--) {
          _gotoxy(x,y-i);
          printf("...");
       }
    }

  6. #6
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    Thanks for the help guys, I'll give this all a try.

  7. #7
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    Sorry guys, I still can't figure this out. All I can get it to do is come up with a 1000 dot at one time.

    Can someone please show me the proper way to do this?

  8. #8
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    I'm not sure what we can show you. We can't run your program and see the problem.

    For the random movement, I'd say limit it to one of the 8 directions, and limit the magnitude of the move from 1 to 10 "dots" (rows and/or cols). If you look at my program I posted, you'll see how to increase the time before the next movement.

    Do you have a version of your program in standard C that we can see what you're referring to?

  9. #9
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    Sorry, I don't. All I have is the software to run this version.

    KISS IDE | KISS Institute for Practical Robotics

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