.endm
-# make VDP word from address adr to d0
-# destroys d7
-.macro VRAM_ADDR_var adr
+.macro CRAM_ADDR reg adr
+ move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+.endm
+
+
+# make VDP word from address adr and store in d0
+.macro XRAM_ADDR_var adr
move.l \adr,d0
- move.l \adr,d7
- and.w #0x3fff,d0
- lsr.w #7,d7
- lsr.w #7,d7
- add.w #0x4000,d0
- lsl.l #7,d0
- lsl.l #7,d0
- lsl.l #2,d0
- or.l d7,d0
+ lsl.l #8,d0
+ lsl.l #8,d0
+ rol.l #2,d0
+ lsl.b #2,d0
+ lsr.l #2,d0
.endm
-.macro CRAM_ADDR reg adr
- move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+.macro VRAM_ADDR_var adr
+ XRAM_ADDR_var \adr
+ or.l #0x40000000,d0
.endm
-/* For indirect (variable) addresses */
-.macro CRAM_ADDR_var reg adr
- move.l \adr,d6
- move.l \adr,d7
- and.w #0x3fff,d6
- lsr.w #7,d7
- lsr.w #7,d7
- add.w #0xc000,d6
- lsl.l #7,d6
- lsl.l #7,d6
- lsl.l #2,d6
- or.l d7,d6
- move.l d6,\reg
+.macro CRAM_ADDR_var adr
+ XRAM_ADDR_var \adr
+ or.l #0xc0000000,d0
.endm
jsr init_gfx
/* Load color data */
- movea.l #0,a3
- movea.l #colors,a4
- moveq.l #(colors_end-colors)/2,d4
+ movea.l #0,a0
+ movea.l #colors,a1
+ moveq.l #(colors_end-colors)/2,d0
jsr load_colors
/* load patterns */
- movea.l #0,a3
- movea.l #font,a4
- move.l #128,d4
+ movea.l #0,a0
+ movea.l #font,a1
+ move.l #128,d0
jsr load_tiles
/* generate A layer map */
movea.l #0xe000,a6
move.l #28-1,d4
lmaploop0:
- movea.l a6,a3
+ movea.l a6,a0
jsr load_prepare
move.l #64/2-1,d3
-0: move.l #0x00000000,(a3)
+0: move.l #0x00000000,(a0)
dbra d3,0b
add.l #64*2,a6
dbra d4,lmaploop0
/* generate B layer map */
- movea.l #0xc000,a3
+ movea.l #0xc000,a0
jsr load_prepare
move.l #64*28/2-1,d3
-0: move.l #0x00000000,(a3)
+0: move.l #0x00000000,(a0)
dbra d3,0b
/* upload sprite data */
- movea.l #0xfc00,a3
+ movea.l #0xfc00,a0
jsr load_prepare
- movea.l #sprite_data,a0
+ movea.l #sprite_data,a1
move.l #(sprite_data_end-sprite_data)/2-1,d3
-0: move.l (a0)+,(a3)
+0: move.l (a1)+,(a0)
dbra d3,0b
jsr wait_vsync
rts
-
-#################################################
-# #
-# Load tile data from ROM #
-# #
-# Parameters: #
-# a3: VRAM base #
-# a4: pattern address #
-# d4: number of tiles to load #
-# Destroys a2,d0,d7... #
-# #
-#################################################
+# Load tile data from ROM
+# a0: VRAM base
+# a1: pattern address
+# d0: number of tiles to load
+# destroys d1
load_tiles:
- move.l #GFXCNTL,a2
- VRAM_ADDR_var a3
- move.l d0,(a2)
- lsl #3,d4
+ move.l d0,d1
+ VRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
- move.l #GFXDATA,a3
- subq.l #1,d4
-_copy_tile_data:
- move.l (a4)+,(a3)
- dbra d4,_copy_tile_data
+ move.l #GFXDATA,a0
+ lsl.w #3,d1
+ subq.l #1,d1
+0:
+ move.l (a1)+,(a0)
+ dbra d1,0b
rts
# Prepare to write to VDP RAM @a3
-# a3: VRAM base
-# a3 set to VDP data port for convenience
-# destroys a2,d0,d7
+# sets a0 to VDP data port for convenience
+# a0: VRAM base
+# destroys d0
load_prepare:
- move.l #GFXCNTL,a2
- VRAM_ADDR_var a3
- move.l d0,(a2)
- move.l #GFXDATA,a3
-
+ VRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
+ move.l #GFXDATA,a0
rts
-#################################################
-# #
-# Load color data from ROM #
-# #
-# Parameters: #
-# a3: CRAM base #
-# a4: color list address #
-# d4: number of colors to load #
-# #
-#################################################
+# Load color data from ROM
+# a0: CRAM base
+# a1: color list address
+# d0: number of colors to load
+# destroys d1
load_colors:
- move.l #GFXCNTL,a2
- CRAM_ADDR_var d0,a3
- move.l d0,(a2)
+ move.l d0,d1
+ CRAM_ADDR_var a0
+ move.l d0,(GFXCNTL).l
- move.l #GFXDATA,a3
- subq.w #1,d4
-_copy_color_data:
- move.w (a4)+,(a3)
- dbra d4,_copy_color_data
+ move.l #GFXDATA,a0
+ subq.w #1,d1
+0:
+ move.w (a1)+,(a0)
+ dbra d1,0b
rts
-#################################################
-##
-## print
-# a0 - string
-# d0 - x
-# d1 - y
+
+# print
+# a0 - string
+# d0 - x
+# d1 - y
+# destroys a1
print:
+ move.l a0,a1
lsl.w #6,d1
add.w d1,d0
- movea.l #0xe000,a6
lsl.w #1,d0
- add.w d0,a6
- moveq.l #0,d1
+ movea.l #0xe000,a0
+ add.w d0,a0
+ jsr load_prepare
+ moveq.l #0,d0
_print_loop:
- move.b (a0)+,d1
+ move.b (a1)+,d0
beq _print_end
- move.l a6,a3
- jsr load_prepare
- move.w d1,(a3)
- addq.l #2,a6
+ move.w d0,(a0)
jmp _print_loop
_print_end:
notaz.gp2x.de / megadrive.git / blobdiff