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RPL Newbie
12-20-2017, 02:20 AM
Post: #21
RE: RPL Newbie
(12-20-2017 01:52 AM)Tim Wessman Wrote:  Here's an example program included with the latest beta for a game. If you feel you can read and follow this, you shouldn't have too much trouble doing fairly basic things I think. Smile

Oh, very nice graphic example, the games will always be the best practice of graphic programming.

Viga C | TD | FB
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12-20-2017, 06:33 PM
Post: #22
RE: RPL Newbie
(12-20-2017 01:52 AM)Tim Wessman Wrote:  
(12-19-2017 09:11 PM)larthurl Wrote:  If I do get a Prime, luckily (I think) i don't have to unlearn RPL since I've never used a 48,49,50. My experience is RPN keystroke programming, very rusty by now since I really haven' used it in 20 + years.
I've also never used PASCAL, but am willing to give the Prime HPPPC a try.
So it should be fun, if not time consuming.

Here's an example program included with the latest beta for a game. If you feel you can read and follow this, you shouldn't have too much trouble doing fairly basic things I think. Smile

Where it gets tricky is trying to integrate CAS calculations in and we still have some work there to make it easier.

Code:
// This example program is a "tunnel" game.
// A game where the player guides a triangle
// in a randomly moving tunnel and needs to
// avoid hitting the sides.

// first, we place a pragma directive to indicate
// which settings we use in our program and
// avoid compilation errors if the calculator
// does not match our settings
#pragma mode( separator(.,;) integer(h32) )


// Points is an exported, global variable
// in order to allow the user to see his score
// even after the program has ended.
// Had we not put the variable as a global
// this would have not be possible
export Points= 0;

// Tunnel is the main function of the program
export Tunnel()
begin
  // First, we initialize all the variables and items
  // used by the program.
  
  // Set the point counter to 0
  Points:= 0;
  // detect the screen width and height
  local width= grobw_p(G0), height= grobh_p(G0);
  // playery is the vertical position of the player on the
  // screen. We initialize it at 1/2 the screen
  local playery= height/2;
  // space will we the width of the tunnel
  // we initialize it at 1/4 of the screen height
  local space= height/4;
  // topy will be the location of the tunnel on the
  // screen. We initialize it centered on the screen
  local topy= (height-space)/2;
  // G1 will be used to draw outside of the
  // screen in order to reduce flicker.
  // we make G1 the same size as the screen and erase it
  dimgrob_p(G1, width, height, #FFFFFF);
  // speed is the number of millisecond in between frames
  // we start at 300ms and we slowly decrease it to make the game harder
  local speed= 300;
  // nextFrame will contain the time when we need to display the next
  // frame. This is set to now plus the speed
  local nextFrame= ticks+speed;
  // nextspeedup contains the moment when we want to next increase the
  // dificulty of the game by speeding it up AND reducing the tunnel size
  local nextspeedup= ticks+10000;
  // movespeed contains the number of pixels by which the user can move per frame
  local movespeed= 5;
  // positions will contain a list of topy/space pairs associated with all the tunnel
  // segments visible on the screen. This will be used to test for collision
  // The tunnel is generated on the right and slowly moves left
  // collisions will only be detected on the left. So, we need to
  // record every new right position, and keep it in memory until it becomes
  // the left position and is used for collision test. This is what is saved here
  // We initializes the list with the screen height as the full screen is valid at the begining.
  local positions= makelist({0, height}, I, 0, width/4);

  // we now get to the core of the game
  // while the player is "in the tunnel" (tested by comparing the user position
  // with the leftmost position in the position list
  // the +15 comes from the fact that the user triangle is 15 pixels heigh
  while playery>positions(1,1) and playery+15<positions(1,2) do
    // Draw the new part of the tunnel. A top and bottom blue part and a middle white
    rect_p(G1, width-5, 0, width-1, topy, #FF); 
    rect_p(G1, width-5, topy+1, width-1, topy+space, #FFFFFF); 
    rect_p(G1, width-5, topy+space, width-1, height-1, #FF); 
    // Copy the back buffer to the screen
    blit(G0, G1);
    // Draw the "user". A color changing triangle of height 15
    triangle_p(G0, {0, playery, #FF0000}, {15, playery+8, #00FF00}, {0, playery+15, #FF0000});

    // start working on the next frame
    // first, shift the back buffer graphic 5 pixels to the left
    blit_p(G1, 0, 0, G1, 4, 0);
    // remove the first item from the position list
    positions:= positions({2,size(positions)});
    // add the current position at the end of the position list
    positions(0):= {topy, topy+space};
    // if the up key is pressed, move the player up (if possible)
    if iskeydown(2) and playery>0 then playery:= playery-movespeed; end;
    // if the down key is pressed, move the player down (if possible)
    if iskeydown(12) and playery+15<height then playery:= playery+movespeed; end;
    // randombly move the tunnel up or down (if possible)
    if rand<0.5 then
      if topy>0 then topy:= topy-1; end;
    else
      if topy+space<height then topy:= topy+1; end;
    end;
    // increase the user's point count
    Points:= Points+1;
    
    // get "now"
    local now= ticks;
    // if we need to make the game harder
    if now>nextspeedup then 
      // calculate next time we need to make the game harder
      nextspeedup:= nextspeedup+10000;
      // increase the speed
      speed:= speed*0.9; 
      // keep user speed move constant compare with normal time
      movespeed:= movespeed*0.9; 
      // make tunnel smaller
      space:= space*0.9; 
    end;
    // wait as needed for the next frame
    wait((nextFrame-now)/1000);
    // calculate when the next frame needs to happen
    nextFrame:= nextFrame+speed;
  end;

  // out of the while loop. The user has lost
  // tell him how many points he has!
  msgbox("You have "+Points+" Points!");
  // also return the point count on the stack
  return Points;
end;

thanks, Tim
I will consider this an "exercise for the student" Wink
I printed it and will review over the holidays.

.....Art
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