HRLC stands for High Resolution - Low Color. It is a technique for creating prototype and place-holder sprites for games. In general, the practice lives up to it's name, most people using this technique use only three colors —- an outline, a "flat" color, and a color used to signify transparency. On the right is such an image that shows both in original size and enlarged to show the individual pixels in detail.
Target resolution for HRLC sprites is usually 640x480 to 800x600. With 640x480, the tilesize is 32. With 800x600 resolution, the tilesize is 40. The example image to the right targets 640x480 resolution, which is more than twice the resolution of the Super NES.
As the name implies, colors are minimal. Each color has a purpose, rather than an aesthetic effect. There are generally one of two sets of colors used during the prototype phase :
If only 3 colors are used, they have these purposes :
- Usually drawn first, the outline color does what you think it does, outline the features of the sprite. In the example image, the outline color is black.
- The base color of the sprite. In the example image, the "flat" color is white.
- The transparent color marks what should be transparent in the game. In the example image, the transparent color is dark gray. The transparent color varies from sprite to sprite, depending on the general color of the expected background.
If 5 colors are used, two colors are added to the previous three. Highlight and Shadow.
- The highlight color is used for areas facing the light direction. It is a lighter color of the same hue as the flat color.
- The shadow color is used for areas opposing the light direction. It is a darker color of the same hue as the flat color.