8 replies to this topic

[jbs30000]

Update * Please check out post #9 for a new and better demo, thank you. * Update

OK, you really can't do much, but here is a small demo of the DPC+ Super Mario game I'm working on. The sprites are all by PAC-MAN-RED because he makes sprites way better than I do.

Right now you can walk through the pipes. This will be fixed when pfread is implemented. There's no scrolling like in my other version because I need to wait until pfscroll is implemented.

Pressing the fire button when walking makes you walk fast. And right now when you jump or fall you can control Mario as if he was walking. This will be fixed later.

Touch the plant and you will die and the game resets. As for the turtle Koopa...there are some glitches, but running into him head first should kill you, and jumping on him will turn him upside down, and jumping on him again will turn him right-side up.
 Main.bas.bin   32K   56 downloads  Main.bas   26.36K   14 downloads

Edited by jbs30000, Wed Nov 16, 2011 3:12 AM.

[jbs30000]

I'll mention one more thing. In the old version of the game I was working on, I wasn't too sure how I would have Mario jump up and hit bricks that contained power-up items. But with 10 sprites in DPC+ this will no longer be a problem.

I have the last four sprites dedicated to power-up bricks. Mario jumps up, a collision with one of the sprites is registered, and it gives a power-up item.

Actually though, I think I wrote myself into a corner. I may have to turn the brick into the power-up item rather than have the item rise up from the brick. But at least I can differentiate between regular bricks and power-up bricks.

Edit: Oh, and let me know if anything should be changed. I mean, there's not much in the demo, but if you'd like the turtle to move faster for example, or you have a better looking cloud or pipe design for example, then let me know. I am going to keep Mario's speed the same.

Edited by jbs30000, Sun Nov 6, 2011 7:42 PM.

[theloon]

With the extra memory and/or pushing popping stack feature I wonder if an array for solid things on-screen is possible..

[jbs30000]

It shouldn't be needed once the DPC+ kernel has pfread. Using that I can check in front of Mario to see if he walks into a pipe, above Mario to see if he jumps up into a brick, and below Mario to see if he lands on a brick, pipe, or the floor.

[jbs30000]

If anybody can tell me why my collision detection routine doesn't work all the time I'd really appreciate it.
For this post I'm adding REMs that aren't in the program just in case anybody doesn't know what what I'm doing.
For this example we'll assume I pushed 12 player2y player2x. 12 is the height of a turtle.

Mario_Crash rem stack should have height, Y pos, X pos
rem All sprites have a max of 8 pixels wide.  TempB holds player player2x
TempA=player0x+7: pull TempB: TempC=TempB+7
rem TempD = player2x to player2x+7
for TempD=TempB to TempC
rem If any player2 pixel has the same x position as any player0 pixel then check for y position match.
if TempD>=player0x&&TempD<=TempA then goto Check_Y
next
rem The other two values on the stack aren't going to be used, but they still need to be pulled.
pull TempA: pull TempA
rem Since player2 is in front of or behind player0 then return that the sprites aren't touching.
TempE=False: return
rem Now check the y positions.  This is pretty much the same process as checking the x positions.
Check_Y
if Mario_is_Large then TempA=player0y+15 else TempA=player0y+9
pull TempB: pull TempC: TempC=TempC+TempB
for TempD=TempB to TempC
	if TempD>=player0y&&TempD<=TempA then TempE=True: return
next
TempE=False: return

Now, Mario touching the plant always works, but Mario touching the turtle doesn't always work. Here's some of the code for when Mario touches the turtle.
Again, I've added REMs for this post so you know what I'm trying to accomplish.

Turtle_Collision
if !Mario_is_Falling then goto Common_Collision_Options
rem if Mario is falling, then he flips the turtle upside down or rightside up.
if !Turtle_UpsideDown then Turtle_UpsideDown=True else Turtle_UpsideDown=False
rem Get the upside down or right-side up sprite for the turtle.
if Turtle_UpsideDown then gosub Turtle_U bank5 else gosub Turtle_A bank5
rem Since Mario was falling, stop the fall and make him jump up 8 pixels.
Mario_is_Falling=False: Mario_is_Jumping=True: player0y=player0y-1
rem Shrink_Timer makes Mario invincible while it is >0.  In the main routine it gets reduced by 1 until it reaches 0.
Jump_Height=8: Shrink_Timer=24
return

And finally, if Common_collision_Options is called then if Mario is large he's shrunk and given some Shrink_Timer time. If Mario is small, then he dies.

Edited by jbs30000, Mon Nov 7, 2011 11:30 PM.

[jbs30000]

I found a perfect way to detect which sprites are colliding with each other. Now that I've done that I'll add power-up bricks to the demo.

[theloon]

What is the perfect way? Collision has always been one of my weak points.

[jbs30000]

OK, take players 0 and 1.
If player 0 ends horizontally before player 1 starts, or if it starts after player 1 ends then there's no collision. The same thing goes vertically. Otherwise, there's a collision.
For example, pretend players 0 and 1 are 8x8 squares. If player0x=0 and player0y=0 then horizontally and vertically player0 is 0 to 7, so if player1x is 8 or greater or player1y is 8 or greater, then there's no crash.

Obviously that's a big, "Well duh!," so here's my code. There might be a better way to code this, but here's how I do it.
First, my temp variables

dim TempA=t
dim TempB=u
dim TempC=v
dim TempD=w
dim TempE=x

Now the crash code. I go to this if collision(player0, player1) is true. If player 0 and 1 collide then TempE[0]=1. If player 0 and 2 crash then TempE[1]=1, etc...

Mario_Enemy_Crash
TempA=player0x+7
if Mario_is_Large then TempB=player0y+15 else TempB=player0y+9
TempE=0

Mar_Crash_1
TempC=player1x+7: TempD=player1y+11
if TempA<player1x||player0x>TempC then goto Mar_Crash_2
if TempB<player1y||player0y>TempD then goto Mar_Crash_2
TempE{0}=1

Mar_Crash_2
TempC=player2x+7
if Enemy1_is_a_Turtle then TempD=player2y+12 else TempD=player2y+9
if TempA<player2x||player0x>TempC then goto Mar_Crash_3
if TempB<player2y||player0y>TempD then goto Mar_Crash_3
TempE{1}=1

Mar_Crash_3
TempC=player3x+7: TempD=player3y+9
if TempA<player3x||player0x>TempC then goto Mar_Crash_4
if TempB<player3y||player0y>TempD then goto Mar_Crash_4
TempE{2}=1

Mar_Crash_4
TempC=player4x+7: TempD=player4y+9
if TempA<player4x||player0x>TempC then return
if TempB<player4y||player0y>TempD then return
TempE{3}=1
return

[jbs30000]

I present another update, and I'm really proud of this one. It still is only on the one screen but there are some improvements.

• After you jump on the turtle, you can push him (to the left or right).
  
• Just like in Super Mario Bros jumping on an upside down turtle won't make him go upright again like in my first demo.
  
• There's a power-up brick you can jump up into and a mushroom pops up. Touching the mushroom will make you large.

You'll notice some bugs. Here they are, and the reason behind them.

• The mushroom doesn't move. This will be fixed when DPC+ has pfread.
  
• When you jump on the turtle you might bounce a few times. In general Mario jumping and falling needs to be worked on. Again, I will when I can use pfread.
  
• After flipping the turtle upside down you can push it, but after touching it you have to quickly move in the other direction or you'll die (or shrink if you're large).
  
• When you push the upside down turtle it doesn't move fast like in the original game. Both 3 and 4 are because the routine I'm using for moving the turtle is not the actual code that I'll use for the game. It's only for the demo and will be fixed in the actual game.

Anyway, I'm proud because even though this is only one screen, this is way more than I accomplished on my attempt using the regular bB kernal.
 Main.bas.bin   32K   28 downloads  Main.bas   32.81K   13 downloads