rockbox/apps/plugins/sdl/progs/quake/d_copy.S
Franklin Wei 5d05b9d3e9 Quake!
This ports id Software's Quake to run on the SDL plugin runtime. The
source code originated from id under the GPLv2 license. I used
https://github.com/ahefner/sdlquake as the base of my port.

Performance is, unsurprisingly, not on par with what you're probably
used to on PC. I average about 10FPS on ipod6g, but it's still
playable.

Sound works well enough, but in-game music is not supported. I've
written ARM assembly routines for the inner sound loop. Make sure you
turn the "brightness" all the way down, or colors will look funky.

To run, extract Quake's data files to /.rockbox/quake. Have fun!

Change-Id: I4285036e967d7f0722802d43cf2096c808ca5799
2019-07-19 22:37:40 -04:00

149 lines
2.5 KiB
ArmAsm

//
// d_copy.s
// x86 assembly-language screen copying code.
//
#include "asm_i386.h"
#include "quakeasm.h"
#include "asm_draw.h"
.data
LCopyWidth: .long 0
LBlockSrcStep: .long 0
LBlockDestStep: .long 0
LSrcDelta: .long 0
LDestDelta: .long 0
#define bufptr 4+16
// copies 16 rows per plane at a pop; idea is that 16*512 = 8k, and since
// no Mode X mode is wider than 360, all the data should fit in the cache for
// the passes for the next 3 planes
.text
.globl C(VGA_UpdatePlanarScreen)
C(VGA_UpdatePlanarScreen):
pushl %ebp // preserve caller's stack frame
pushl %edi
pushl %esi // preserve register variables
pushl %ebx
movl C(VGA_bufferrowbytes),%eax
shll $1,%eax
movl %eax,LBlockSrcStep
movl C(VGA_rowbytes),%eax
shll $1,%eax
movl %eax,LBlockDestStep
movl $0x3C4,%edx
movb $2,%al
outb %al,%dx // point the SC to the Map Mask
incl %edx
movl bufptr(%esp),%esi
movl C(VGA_pagebase),%edi
movl C(VGA_height),%ebp
shrl $1,%ebp
movl C(VGA_width),%ecx
movl C(VGA_bufferrowbytes),%eax
subl %ecx,%eax
movl %eax,LSrcDelta
movl C(VGA_rowbytes),%eax
shll $2,%eax
subl %ecx,%eax
movl %eax,LDestDelta
shrl $4,%ecx
movl %ecx,LCopyWidth
LRowLoop:
movb $1,%al
LPlaneLoop:
outb %al,%dx
movb $2,%ah
pushl %esi
pushl %edi
LRowSetLoop:
movl LCopyWidth,%ecx
LColumnLoop:
movb 12(%esi),%bh
movb 8(%esi),%bl
shll $16,%ebx
movb 4(%esi),%bh
movb (%esi),%bl
movl %ebx,(%edi)
addl $16,%esi
addl $4,%edi
decl %ecx
jnz LColumnLoop
addl LDestDelta,%edi
addl LSrcDelta,%esi
decb %ah
jnz LRowSetLoop
popl %edi
popl %esi
incl %esi
shlb $1,%al
cmpb $16,%al
jnz LPlaneLoop
subl $4,%esi
addl LBlockSrcStep,%esi
addl LBlockDestStep,%edi
decl %ebp
jnz LRowLoop
popl %ebx // restore register variables
popl %esi
popl %edi
popl %ebp // restore the caller's stack frame
ret
#define srcptr 4+16
#define destptr 8+16
#define width 12+16
#define height 16+16
#define srcrowbytes 20+16
#define destrowbytes 24+16
.globl C(VGA_UpdateLinearScreen)
C(VGA_UpdateLinearScreen):
pushl %ebp // preserve caller's stack frame
pushl %edi
pushl %esi // preserve register variables
pushl %ebx
cld
movl srcptr(%esp),%esi
movl destptr(%esp),%edi
movl width(%esp),%ebx
movl srcrowbytes(%esp),%eax
subl %ebx,%eax
movl destrowbytes(%esp),%edx
subl %ebx,%edx
shrl $2,%ebx
movl height(%esp),%ebp
LLRowLoop:
movl %ebx,%ecx
rep/movsl (%esi),(%edi)
addl %eax,%esi
addl %edx,%edi
decl %ebp
jnz LLRowLoop
popl %ebx // restore register variables
popl %esi
popl %edi
popl %ebp // restore the caller's stack frame
ret