cdogs-sdl/graphics/README.md

This is a simple guide to making sprites that will fit in the style of C-Dogs. Consistency is the most important thing; it doesn't matter how good an individual sprite looks, if it looks different from the rest it will stick out and make the whole thing look bad!

Summary

C-Dogs sprites are:

• Pixel art
• Somewhat limited palette
• Lit from the top-left, with a secondary light from the bottom-left
• Some objects, like pickups, cast a 1px full black shadow along its bottom-right

Colours

Try to use the limited palette that original C-Dogs uses. Not all current sprites are like this (https://github.com/cxong/cdogs-sdl/issues/388).

If you use GIMP, you can also import this palette using

• Windows > Palettes
• Right click the list > Import Palette... > find palette.png
• Open an image you want to palettise
• Image > Mode > Indexed... > Use custom palette > select the imported C-Dogs palette

Lighting

The primary light is from the top-left. This means that:

• Top and left edges are brightest
• The top surface is brighter than the front surface

Take these examples:

There are up to 7 shades used for the various surfaces and edges. Here they are in an ASCII diagram, from brightest (1) to darkest (7):

+---+---------+---+
| 1 |    2    | 3 |
+---+---------+---+
|   |         |   |
| 2 |    3    | 4 |
|   |         |   |
+---+---------+---+
| 3 |    4    | 5 |
+---+---------+---+
|   |         |   |
| 4 |    5    | 6 |
|   |         |   |
+---+---------+---+
| 5 |    6    | 7 |
+---+---------+---+

For round objects in particular, there is a secondary light from the bottom-left. This is just to make the object look nice, and accentuate the roundness.

Shadows

For tall objects and pickups, there's a drop shadow to the bottom-right, 1px thick (unless the object is taller), pure black.