Sprites
(account deleted) 11 Dec 2012 22:47
How do you use sprites?
Coffee + Radiohead = ^^
Sprites
Summary:
The Basics
(account deleted) 11 Dec 2012 22:47
Do you mean in TI-BASIC, or using assembly tools? Regardless, you use sprites as mini pictures, basically. For example, you can have an 8x8 sprite which is basically an 8 pixel by 8 pixel image that you draw to the screen. In BASIC, I like to use the Pt-On( command or Line( command to get the fastest drawing. Alternatively, I like to use the Text( command in some case.
Z80 Assembly>English>TI-BASIC>Python>French>C>0
Either way. I know what they are, but how do I graph them?
Coffee + Radiohead = ^^
Omnicalc has a built-in sprite command in its quick-commands menu (pressing prgm twice). I'm pretty sure batlib has some too, but I wouldn't be the person to ask about that :D
I've tried to use that sprite command before, but whatever I put in, it says error:argument or error:syntax. I'm not using it right.
Coffee + Radiohead = ^^
If you press the plus button when you have the command selected it gives you the syntax.
also: detachedsolutions[dot]com/omnicalc/manual/functions.php#sprite
What may be confusing you is how to come up with the hex data, if you are using BatLib or the BASIC sprite drawing routine I alluded to in a past topic. It works like this:
Look at the number 153. That is 1*102+5*101+3*100. Here is a binary number (binary only uses 1s and 0s since it is base 2):
100110012 = 1*27+0*26+0*25+1*24+1*23+0*22+0*21+1*20=153
Now look at hexadecimal (base 16)
9916=9*161+9*160=153
To create a sprite, you look at its pixels and convert them to binary. Pixel ON=1, Pixel OFF=0. From there, you convert it to hexadecimal. Luckily, every group of 4 binary digits equates to precisely 1 hexadecimal digit. In the above example, we used 100110012. Split that in groups of 4, starting on the left (the lowest digits), you get 1001b and 1001b, both of which are 9. This tells us that the hex for those 8 pixels is 99h.
But what happens if you have something like 1101b? In decimal (base 10), that is 13, but in hexadecimal, we need 16 single digits. We use letters A~F to represent the extra digits, where A=10, B=11, C=12,…, so 1101b=Dh :)
Using asm libraries, you will almost always be creating sprites with a multiple of 8 pixels in each row (8 pixels = 8 binary digits = 8 bits = 1 byte). SO here is a sprite!
00111100 =3Ch
01000010 =42h
10000001 =81h
10000001 =81h
10000001 =81h
10000001 =81h
01000010 =42h
00111100 =3ChCombining all of the hex starting from the top, you get 3C4281818181423C, and this is your sprite data :)
This is how Axe, Grammer, BatLib, and Celtic3 do it, as well as other Assembly tools.
I happen to know BatLib pretty well, so I will show you how to use the command (reading the documentation):
52-HexSprite dim(52,[option],"Hex",Height,X,Y,Logic)This tells us the arguments.
option is 1 if you are using pixel coordinates. I suggest you use this if you want to move the sprite around. Use 0 if you are drawing tiles.
"Hex" is the hex data for the sprite.** I gave an example of "3C4281818181423C"
Height is the height of the sprite in pixels. **In this case, 8.
X is the X coordinate of the sprite (0 to 11 unless using pixel coordinates) We are using Option=1, so use pixel coordinates
Y is the Y coordinate of the sprite. Use 0 to 63
Logic is the method of drawing the sprite:
0-Overwrite simply overwrites the preexisting data
1-AND If wither the pixel on the screen is OFF or the pixel in the sprite is OFF, the pixel output will be OFF. Think of it like multiplication, 0x0=0, 0x1=0, 1x0=0, 1x1=1
2-XOR Any pixels ON in the sprite will invert the pixel on the screen
3-OR Any pixels ON in the sprite will draw ON on the screen. Does not erase pixels
4-Erase Any pixels ON in the sprite will erase the pixel on the screen
There is no width input because it uses the length of the data divided by the
height to find the width (area/width=height). (it rounds up if there isn't
enough data). When using the regular draw mode, the X coordinate is multiplied
by 8. This is to maintain backwards compatibility with older versions of BatLib.
So put it all together:
dim(52,1,"3C4281818181423C",8,X,Y,2
That will invert the sprite on the screen. Do it again to leave no net change on the screen :D
Also, with BatLib, you will need to tell it when to update the screen, using dim(99. This allows for smoother (non flickering) graphics and lets you draw everything you need and not shoe the ser the whole process (this also massively speeds up drawing). This is true for most assembly graphics routines. In BatLib, you can simply combine the two commands. Then, because we want to draw it again, we can combine all three commands:
dim(52,1,"3C4281818181423C",8,X,Y,2,99,52,1,"3C4281818181423C",8,X,Y,2
I would personally keep the sprite date in Ans, to save memory and speed things up.
Z80 Assembly>English>TI-BASIC>Python>French>C>0
/forum/t-601746/sprites#post-