I got a bit overwhelmed with my 3D engine and platformer projects so I decided to do something a bit simpler. So I'm trying to create an old style GameBoy engine from the Link's Awakening days. It's not supposed to be a Zelda clone by any means, who knows what it'll be. That's to be decided if anything.
Some things about it:
The sprites and tiles are colorized on the fly. Each sprite/tile is made up of a 4 color greyscale image and the shades get replaced by a specific color in real-time. I wrote a shader just for this. It's a simple shader really...
Code: Select all
nesShader = love.graphics.newShader[[
extern vec4 color1;
extern vec4 color2;
extern vec4 color3;
extern vec4 color4;
vec4 effect( vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords ){
vec4 pixel = Texel(texture, texture_coords );//This is the current pixel color
if (pixel.a == 0.0) { return vec4(0.0,0.0,0.0,0.0); }
if (pixel.r < 0.25) { return vec4(color4.r/255,color4.g/255,color4.b/255,color4.a/255); }
else if (pixel.r < 0.5) { return vec4(color3.r/255,color3.g/255,color3.b/255,color3.a/255); }
else if (pixel.r < 0.75) { return vec4(color2.r/255,color2.g/255,color2.b/255,color2.a/255); }
else { return vec4(color1.r/255,color1.g/255,color1.b/255,color1.a/255); }
return pixel;
}
]]
You pass each color as a vec4 in 0-255 rgba format and the shader takes care of the rest. (Note all the /255 which basically converts the number into a decimal that the shader can use. It only checks the red component since the colors are greyscale anyway it doesn't need to worry about the rest. But if the alpha is 0 then it just assumes 0 no matter what the colors are. Is this the most optimized it could get? I dunno. It does add a bit to the rendering time but not enough that it takes the FPS low at all. It still leaves plenty of idle time and breathing room. In the video above, the floor uses a grid of 4 8x8 pixel tiles. Each has 4 colors max.
I decided on the standard classic GameBoy resolution of 160x144. This gives you a tile grid of 10x9. Map screens take up 10x8 tiles with one tile being used for the HUD/statusbar. I have been seriously contemplating switching to the GBA resolution instead for a bit more flexibility since I'd have a screen size of 240x160 (15x10 tiles) plus I could do some more effects like make the HUD overlay the game itself and free scrolling maps without it feeling out of place. But that takes me back to why I started the project. Simplicity. I want to make a world of my own. But I want to keep it cozy. So by keeping the resolution and tile count low, it means I have to think about how the world looks.
Maps are limited to 16x16 screens (160x128 tiles) with optional smaller area sizes (Current MapSet creator limits to sizes in the 4, 8, 12 or 16 range.) for things like dungeons. So you'd have the overworld in one mapset. Each dungeon in its own set. Building interiors in another mapset. Caves in another one.
A scripting system I ripped right out of my platformer engine (In which I never even utilized it there. So now it's getting some use.) that can do a bunch of things right now like:
- Tell an entity what to do. Like moving it around. Or set its position. Or in the future activate an animation sequence.
- Displaying a dialog box or query. The text string has formatting codes so you can change the color of the text, or make it type slower. And it's animated in a neat way.
- Setting or getting flag values (Variables) and checking their values.
- It has working If/Then blocks, including some that check specific values like the most recent Query value.
- Pause the script for a set amount of time.
- Enable or disable input and pause or unpause updating of entities.
- Getting a random value and doing stuff based on its value.
- Change the current mapset.
- It even has GOTO for making loops or skipping parts of the script.
Scripts are structured using a simple syntax I made myself when I was designing my DOS QuickBASIC RPG. It looks like so:
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>>START
ENTCOMMAND player visibility 0
DISABLEINPUT
PAUSEENTITYUPDATE
ENTCOMMAND player warp 0,0 9,3.5
ENTCOMMAND player visibility 1
ENTCOMMAND player move left 4.5
WAIT 0.1
ENTCOMMAND player move down 0
//In the above command, the zero lets you make the player turn without actually moving.
//Also, this is a comment.
MESSAGEBOX This is a {CG}sample{CD}\nmessage. {W0.6}It's\n{CV}s{W0.1}u{W0.1}p{W0.1}e{W0.1}r{W0.1} {CY}a{W0.1}w{W0.1}e{W0.1}s{W0.1}o{W0.1}m{W0.1}e{W0.1}{CD}! {W0.3}{CR}^
QUERY End this {CR}script{CD}\nnow? || Yes || No
IFANSWER = YES
JUMPTO EXITEARLY
ENDIF
JUMPTO START
>>EXITEARLY
RESUMEENTITYUPDATE
ENABLEINPUT
ENDSCRIPT
A built-in editor from the beginning. You can edit it in place with the press of a key. It's not really there yet but it's a start.
I have to decide the limitations I want though. Right now the colors can be anything. But I want to create a palette. A limited palette of maybe 64 colors at most. Possibly 32. I've been doing a lot of research about video game console/PC color palettes. I kind of want to just use the NES color palette. But it's only like 54 colors not counting the duplicates and similar ones. I'd be more flexible though. Maybe use some creativity and modify the colors to suit my needs. I was also looking at the Pico8 color palette. (16 colors) It's really nice looking. But again, it's only 16 colors. Then again, Pico8 devs have done some damn amazing things with those 16 colors. Just Google it. You'll be amazed. Either way, by having a set color palette I could keep things more genuine.
Planning to study them later.