1  #ifndef _SPRITE_ASM_CONST
 2  #define _SPRITE_ASM_CONST
 3  
 4  // Put every function in its own ELF section, to permit linker GC
 5  .macro decl_func name
 6  .section .time_critical.\name, "ax"
 7  .global \name
 8  .type \name,%function
 9  .thumb_func
10  \name:
11  .endm
12  
13  // Assume RGAB5515 (so alpha is bit 5)
14  // Note the alpha bit being in the same position as RAGB2132 is a coincidence.
15  // We are just stealing an LSB such that we can treat our alpha pixels in the
16  // same way as non-alpha pixels when encoding (and the co-opted channel LSB
17  // always ends up being set on alpha pixels, which is pretty harmless)
18  
19  #define ALPHA_SHIFT_16BPP 6
20  
21  // Assume RAGB2132 (so alpha is bit 5)
22  
23  #define ALPHA_SHIFT_8BPP 6
24  
25  
26  #endif