Vic's QBasic Programming Tutorial Basic Tutorial III.V (3.5) GAME TEQUINIQUES REVISTITED!! ----------------------------------------------------------------------------- Ok! OK!!! I have had enought E-mails about people not understanding my game tutorial... So, I figured it was probly my fault for not explaining it good enough... This tutorial works hand in hand with tutor #3 so make sure you read it first... ---- First of all, I will once again I will cover How to move a sprite... I will cover it a few times now... --------------------------------------------------------------------------- OK! here we go! Every Sprite has a X value and a Y value... Let me draw a grid for you to get the picture better... 1 2 3 4 5 6 7 8 9 10 11 12 ------------------------------------------------------------- 1 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 2 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 3 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 4 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 5 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- Do you remember your times table?? Its exactly like that... Ok, Imagine that We wanted to put sprite at this point (where the XX is) 1 2 3 4 5 6 7 8 9 10 11 12 ------------------------------------------------------------- 1 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 2 | | | | | | | | | | | | | | | | | | XX | | | | | | | | ------------------------------------------------------------- 3 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 4 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 5 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- Believe it or not, the X value would be 5 and the Y value would equal 2... So its like this... X = 5 Y = 2 Remebmer from the graphics tutorial?? X goes left to right, and Y goes up and down... --- Ok, You most likely get that... If you don't, just think about it for a while... --- Now, What if we wanted to move that XX one space to the RIGHT? What would its X value be now?? Let me show you this... 1 2 3 4 5 6 7 8 9 10 11 12 ------------------------------------------------------------- 1 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 2 | | | | | | | | | | | | | | | | | | XX | ZZ | | | | | | | ------------------------------------------------------------- 3 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 4 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 5 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- The XX is where the sprite is now, and ZZ is where we want the sprite to go, which is one space to the right... So, The X value of the XX is 5 remember, if we want it to be one place to the right, (where the ZZ is) what should the next X value be? 6 right? So, if we want the sprite to move one space to the right what should we do? This is what it used to equall... X = 5 Y = 2 Now, it equalls X = 6 Y = 2 Remember, X = left to right and Y = up and down, So, now, if we wanted to move the sprite down one, we would change the Y value... So the coordinates would equal X = 6 Y = 3 So it would now be here... (where the AA is) 1 2 3 4 5 6 7 8 9 10 11 12 ------------------------------------------------------------- 1 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 2 | | | | | | | | | | | | | | | | | | XX | ZZ | | | | | | | ------------------------------------------------------------- 3 | | | | | | | | | | | | | | | | | | | AA | | | | | | | ------------------------------------------------------------- 4 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- 5 | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------------------------------- If we were to put this into a formula, what would it look like? If we wanted to move the sprite ONE (1) space to the right what should we put??? X = X + 1 Imagine X was equal to 5... Now what does X equal? 6 right??? YES! That would be one space to the right... If we wanted to move the sprite one down what would we do? Y = Y + 1 So, if Y was equal to 2 Y would now equal 3!!! One space down... -------- I don't know how I can make this any clearer... IF you still don't understand it, just keep looking at others source code... -----------------------------------------------------------------------------