NML:Alternative sprites

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Revision as of 21:14, 3 March 2012 by Hirundo (talk | contribs) (Add info on mask files)
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Block Syntax

A alternative_sprites block allows you to specify alternative sprites (zoom levels and / or 32bpp) that are drop-in replacements for some real sprites in your grf. The syntax is as follows:

alternative_sprites(block_name, zoom_level, type[, filename[, mask_filename]]) {
	list of realsprites
}

block_name is the name of the replace / base_graphics, replace_new, font_glyph or spriteset-block for which you want to provide alternative sprites. zoom_level can be

name tile size description
ZOOM_LEVEL_IN_4X 256 x 127 4x zoom in
ZOOM_LEVEL_IN_2X 128 x 63 2x zoom in
ZOOM_LEVEL_NORMAL 64 x 31 normal tile size
ZOOM_LEVEL_OUT_2X 32 x 15 2x zoom out
ZOOM_LEVEL_OUT_4X 16 x 7 4x zoom out
ZOOM_LEVEL_OUT_8X 8 x 3 8x zoom out

The type argument specifies which kind of sprite follows. This may be either BIT_DEPTH_8BPP or BIT_DEPTH_32BPP.

Specifying a filename is optional, it's only useful if you have multiple sprites in the same file. If every sprite is in a separate file you'll have to specify the filename for each realsprite anyway, so you can leave it out of the alternative_sprites-block.

For 32bpp only, you can also specify a default filename to use for mask sprites. These (8bpp) sprites have the same size and offsets as the normal sprites and are used for recolouring purposes. See the real sprites page for more info.

An example for an implementation

 // Foster Express tram
 spriteset(foster_express_set, "opengfx_generic_trams1.pcx") {
   [ 48,56,  8,18,   -3,-10]
   [ 64,56, 20,19,  -14, -5]
   [ 96,56, 28,15,  -14, -8]
   [144,56, 20,19,   -6, -7]
   [176,56,  8,18,   -3,-10]
   [192,56, 20,19,  -14, -9]
   [224,56, 28,15,  -14, -8]
   [272,56, 20,19,   -6, -7]
 }
 
 alternative_sprites(foster_express_set, ZOOM_LEVEL_IN_2X, BIT_DEPTH_8BPP, "opengfx_generic_trams1.pcx") {
   [ 48,56,  8,18,   -3,-10]
   [ 64,56, 20,19,  -14, -5]
   [ 96,56, 28,15,  -14, -8]
   [144,56, 20,19,   -6, -7]
   [176,56,  8,18,   -3,-10]
   [192,56, 20,19,  -14, -9]
   [224,56, 28,15,  -14, -8]
   [272,56, 20,19,   -6, -7]
 }
 
 alternative_sprites(foster_express_set, ZOOM_LEVEL_NORMAL, BIT_DEPTH_32BPP, "opengfx_generic_trams1.png") {
   [ 48,56,  8,18,   -3,-10]
   [ 64,56, 20,19,  -14, -5]
   [ 96,56, 28,15,  -14, -8]
   [144,56, 20,19,   -6, -7]
   [176,56,  8,18,   -3,-10]
   [192,56, 20,19,  -14, -9]
   [224,56, 28,15,  -14, -8]
   [272,56, 20,19,   -6, -7]
 }