A great feature of the Amstrad CPC plus is hardware sprites. Hardware sprites are handled by the [[ASIC]]. The ASIC can handle up to 16 sprites per [[scanline]], each hardware sprite is always 16 x 16 pixels of size.
== The data == Each sprite can display 15 distinct colours, the pixel colours are indexed #0 - #F. Index #0 is always transparency, whereas index #1 - #F is the colour index in the sprite palette. To define a sprite in the ASIC. 16 x 16 (256) bytes must be transferred to the ASIC. The format of the data is straight forward. The data is organized in a linear manner. Each sprite pixel uses a single byte, the upper nibble is ignored by the ASIC. == The colour palette == The ASIC can handle 4096(16x16x16) colours. Each colour is defined as values of '''red''', '''green''' and '''blue'''.Each value is handled as 4bit values. The hardware code send to the ASIC is #0grb. In the below example changing the palette index colour 1 to value #0F00 gives a '''green''' Pac sprite. [[Image:Green pac.png]] changing the palette index colour 1 to value #00F0 gives a '''red''' Pac sprite. [[Image:Red pac.png]] and finally changing the palette index colour 1 to value #000F gives a '''blue''' Pac sprite. [[Image:Blue pac.png]] == Example == Below is shown an example of how a sprite is organized into raw data. To transfer the sprite data to the ASIC look here: [[Programming:CPC Plus Hardware Sprites|Transfer to ASIC]] [[Image:Cpcplussprite.png|400px]] <geshi lang=Z80>.pac_sprite ; The raw sprite data - to be transfered to the ASIC db #00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00db #00,#00,#00,#00,#00,#00,#01,#01,#01,#01,#00,#00,#00,#00,#00,#00db #00,#00,#00,#00,#01,#01,#01,#01,#01,#01,#01,#01,#00,#00,#00,#00db #00,#00,#00,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#00,#00,#00db #00,#00,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#00,#00db #00,#00,#01,#01,#03,#03,#01,#01,#01,#01,#03,#03,#01,#01,#00,#00db #00,#00,#01,#03,#03,#03,#03,#01,#01,#03,#03,#03,#03,#01,#00,#00db #00,#01,#01,#03,#03,#03,#03,#01,#01,#03,#03,#03,#03,#01,#01,#00db #00,#01,#01,#03,#02,#02,#03,#01,#01,#03,#02,#02,#03,#01,#01,#00db #00,#01,#01,#01,#02,#02,#01,#01,#01,#01,#02,#02,#01,#01,#01,#00db #00,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#00db #00,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#01,#00db #00,#01,#01,#01,#00,#01,#01,#01,#01,#01,#01,#00,#01,#01,#01,#00db #00,#00,#01,#00,#00,#00,#01,#01,#01,#01,#00,#00,#00,#01,#00,#00db #00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00db #00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00,#00 ; Compressed data db #00,#00,#00,#00,#00,#00,#00,#00db #00,#00,#00,#11,#11,#00,#00,#00db #00,#00,#11,#11,#11,#11,#00,#00db #00,#01,#11,#11,#11,#11,#10,#00db #00,#11,#11,#11,#11,#11,#11,#00db #00,#11,#33,#11,#11,#33,#11,#00db #00,#13,#33,#31,#13,#33,#31,#00db #01,#13,#33,#31,#13,#33,#31,#10db #01,#13,#22,#31,#13,#22,#31,#10db #01,#11,#22,#11,#11,#22,#11,#10db #01,#11,#11,#11,#11,#11,#11,#10db #01,#11,#11,#11,#11,#11,#11,#10db #01,#11,#01,#11,#11,#10,#11,#10db #00,#10,#00,#11,#11,#00,#01,#00db #00,#00,#00,#00,#00,#00,#00,#00db #00,#00,#00,#00,#00,#00,#00,#00 .pac_sprite_palette ; Sprite ink 1dw #0CDF ; Red = #D Green = #C Blue = #F ; The gray body; Sprite ink 2dw #0000 ; Red = #0 Green = #0 Blue = #0 ; The black in the PAC's eyes; Sprite ink 3dw #0FFF ; Red = #F Green = #F Blue = #F ; The white in the PAC's eyes</geshi> == See also== *[[Sprites Multiplexing]]*[[Programming:CPC Plus Hardware Sprites]] [[Category:CPC Plus]][[Category: Programming]][[Category:Graphic]]