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Created new subdir: uquake. Pick your favorite U word for the meaning -- Unchained, Ultimate, Ultra, Up Yours, Underworld, Underground, Unified, Unity, etc. You know the drill. This takes care of the "standalone" problem with the wrong name, and the recent snafu with multiple developers working on the same files simultaneously...expect me (and probably others) to start locking dirs when updates are taking place. And yes, this update is really as large as it looks. Software only at the moment, but I will have the makefile updated to build the GL builds as well.
1999-12-26 13:51:52 +00:00
/*
Copyright notice stuff
2000-01-06 13:48:07 +00:00
Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 1999,2000 contributors of the QuakeForge project
Please see the file "AUTHORS" for a list of contributors
Created new subdir: uquake. Pick your favorite U word for the meaning -- Unchained, Ultimate, Ultra, Up Yours, Underworld, Underground, Unified, Unity, etc. You know the drill. This takes care of the "standalone" problem with the wrong name, and the recent snafu with multiple developers working on the same files simultaneously...expect me (and probably others) to start locking dirs when updates are taking place. And yes, this update is really as large as it looks. Software only at the moment, but I will have the makefile updated to build the GL builds as well.
1999-12-26 13:51:52 +00:00
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//
// d_draw.s
// x86 assembly-language horizontal 8-bpp span-drawing code.
//
#include "asm_i386.h"
#include "quakeasm.h"
#include "asm_draw.h"
#include "d_ifacea.h"
#if id386
//----------------------------------------------------------------------
// 8-bpp horizontal span drawing code for polygons, with no transparency.
//
// Assumes there is at least one span in pspans, and that every span
// contains at least one pixel
//----------------------------------------------------------------------
.text
// out-of-line, rarely-needed clamping code
LClampHigh0:
movl C(bbextents),%esi
jmp LClampReentry0
LClampHighOrLow0:
jg LClampHigh0
xorl %esi,%esi
jmp LClampReentry0
LClampHigh1:
movl C(bbextentt),%edx
jmp LClampReentry1
LClampHighOrLow1:
jg LClampHigh1
xorl %edx,%edx
jmp LClampReentry1
LClampLow2:
movl $2048,%ebp
jmp LClampReentry2
LClampHigh2:
movl C(bbextents),%ebp
jmp LClampReentry2
LClampLow3:
movl $2048,%ecx
jmp LClampReentry3
LClampHigh3:
movl C(bbextentt),%ecx
jmp LClampReentry3
LClampLow4:
movl $2048,%eax
jmp LClampReentry4
LClampHigh4:
movl C(bbextents),%eax
jmp LClampReentry4
LClampLow5:
movl $2048,%ebx
jmp LClampReentry5
LClampHigh5:
movl C(bbextentt),%ebx
jmp LClampReentry5
#define pspans 4+16
.align 4
.globl C(D_DrawSpans8)
C(D_DrawSpans8):
pushl %ebp // preserve caller's stack frame
pushl %edi
pushl %esi // preserve register variables
pushl %ebx
//
// set up scaled-by-8 steps, for 8-long segments; also set up cacheblock
// and span list pointers
//
// TODO: any overlap from rearranging?
flds C(d_sdivzstepu)
fmuls fp_8
movl C(cacheblock),%edx
flds C(d_tdivzstepu)
fmuls fp_8
movl pspans(%esp),%ebx // point to the first span descriptor
flds C(d_zistepu)
fmuls fp_8
movl %edx,pbase // pbase = cacheblock
fstps zi8stepu
fstps tdivz8stepu
fstps sdivz8stepu
LSpanLoop:
//
// set up the initial s/z, t/z, and 1/z on the FP stack, and generate the
// initial s and t values
//
// FIXME: pipeline FILD?
fildl espan_t_v(%ebx)
fildl espan_t_u(%ebx)
fld %st(1) // dv | du | dv
fmuls C(d_sdivzstepv) // dv*d_sdivzstepv | du | dv
fld %st(1) // du | dv*d_sdivzstepv | du | dv
fmuls C(d_sdivzstepu) // du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
fld %st(2) // du | du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
fmuls C(d_tdivzstepu) // du*d_tdivzstepu | du*d_sdivzstepu |
// dv*d_sdivzstepv | du | dv
fxch %st(1) // du*d_sdivzstepu | du*d_tdivzstepu |
// dv*d_sdivzstepv | du | dv
faddp %st(0),%st(2) // du*d_tdivzstepu |
// du*d_sdivzstepu + dv*d_sdivzstepv | du | dv
fxch %st(1) // du*d_sdivzstepu + dv*d_sdivzstepv |
// du*d_tdivzstepu | du | dv
fld %st(3) // dv | du*d_sdivzstepu + dv*d_sdivzstepv |
// du*d_tdivzstepu | du | dv
fmuls C(d_tdivzstepv) // dv*d_tdivzstepv |
// du*d_sdivzstepu + dv*d_sdivzstepv |
// du*d_tdivzstepu | du | dv
fxch %st(1) // du*d_sdivzstepu + dv*d_sdivzstepv |
// dv*d_tdivzstepv | du*d_tdivzstepu | du | dv
fadds C(d_sdivzorigin) // sdivz = d_sdivzorigin + dv*d_sdivzstepv +
// du*d_sdivzstepu; stays in %st(2) at end
fxch %st(4) // dv | dv*d_tdivzstepv | du*d_tdivzstepu | du |
// s/z
fmuls C(d_zistepv) // dv*d_zistepv | dv*d_tdivzstepv |
// du*d_tdivzstepu | du | s/z
fxch %st(1) // dv*d_tdivzstepv | dv*d_zistepv |
// du*d_tdivzstepu | du | s/z
faddp %st(0),%st(2) // dv*d_zistepv |
// dv*d_tdivzstepv + du*d_tdivzstepu | du | s/z
fxch %st(2) // du | dv*d_tdivzstepv + du*d_tdivzstepu |
// dv*d_zistepv | s/z
fmuls C(d_zistepu) // du*d_zistepu |
// dv*d_tdivzstepv + du*d_tdivzstepu |
// dv*d_zistepv | s/z
fxch %st(1) // dv*d_tdivzstepv + du*d_tdivzstepu |
// du*d_zistepu | dv*d_zistepv | s/z
fadds C(d_tdivzorigin) // tdivz = d_tdivzorigin + dv*d_tdivzstepv +
// du*d_tdivzstepu; stays in %st(1) at end
fxch %st(2) // dv*d_zistepv | du*d_zistepu | t/z | s/z
faddp %st(0),%st(1) // dv*d_zistepv + du*d_zistepu | t/z | s/z
flds fp_64k // fp_64k | dv*d_zistepv + du*d_zistepu | t/z | s/z
fxch %st(1) // dv*d_zistepv + du*d_zistepu | fp_64k | t/z | s/z
fadds C(d_ziorigin) // zi = d_ziorigin + dv*d_zistepv +
// du*d_zistepu; stays in %st(0) at end
// 1/z | fp_64k | t/z | s/z
//
// calculate and clamp s & t
//
fdivr %st(0),%st(1) // 1/z | z*64k | t/z | s/z
//
// point %edi to the first pixel in the span
//
movl C(d_viewbuffer),%ecx
movl espan_t_v(%ebx),%eax
movl %ebx,pspantemp // preserve spans pointer
movl C(tadjust),%edx
movl C(sadjust),%esi
movl C(d_scantable)(,%eax,4),%edi // v * screenwidth
addl %ecx,%edi
movl espan_t_u(%ebx),%ecx
addl %ecx,%edi // pdest = &pdestspan[scans->u];
movl espan_t_count(%ebx),%ecx
//
// now start the FDIV for the end of the span
//
cmpl $8,%ecx
ja LSetupNotLast1
decl %ecx
jz LCleanup1 // if only one pixel, no need to start an FDIV
movl %ecx,spancountminus1
// finish up the s and t calcs
fxch %st(1) // z*64k | 1/z | t/z | s/z
fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
fxch %st(1) // z*64k | s | 1/z | t/z | s/z
fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
fxch %st(1) // s | t | 1/z | t/z | s/z
fistpl s // 1/z | t | t/z | s/z
fistpl t // 1/z | t/z | s/z
fildl spancountminus1
flds C(d_tdivzstepu) // C(d_tdivzstepu) | spancountminus1
flds C(d_zistepu) // C(d_zistepu) | C(d_tdivzstepu) | spancountminus1
fmul %st(2),%st(0) // C(d_zistepu)*scm1 | C(d_tdivzstepu) | scm1
fxch %st(1) // C(d_tdivzstepu) | C(d_zistepu)*scm1 | scm1
fmul %st(2),%st(0) // C(d_tdivzstepu)*scm1 | C(d_zistepu)*scm1 | scm1
fxch %st(2) // scm1 | C(d_zistepu)*scm1 | C(d_tdivzstepu)*scm1
fmuls C(d_sdivzstepu) // C(d_sdivzstepu)*scm1 | C(d_zistepu)*scm1 |
// C(d_tdivzstepu)*scm1
fxch %st(1) // C(d_zistepu)*scm1 | C(d_sdivzstepu)*scm1 |
// C(d_tdivzstepu)*scm1
faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1 | C(d_tdivzstepu)*scm1
fxch %st(1) // C(d_tdivzstepu)*scm1 | C(d_sdivzstepu)*scm1
faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1
faddp %st(0),%st(3)
flds fp_64k
fdiv %st(1),%st(0) // this is what we've gone to all this trouble to
// overlap
jmp LFDIVInFlight1
LCleanup1:
// finish up the s and t calcs
fxch %st(1) // z*64k | 1/z | t/z | s/z
fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
fxch %st(1) // z*64k | s | 1/z | t/z | s/z
fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
fxch %st(1) // s | t | 1/z | t/z | s/z
fistpl s // 1/z | t | t/z | s/z
fistpl t // 1/z | t/z | s/z
jmp LFDIVInFlight1
.align 4
LSetupNotLast1:
// finish up the s and t calcs
fxch %st(1) // z*64k | 1/z | t/z | s/z
fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
fxch %st(1) // z*64k | s | 1/z | t/z | s/z
fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
fxch %st(1) // s | t | 1/z | t/z | s/z
fistpl s // 1/z | t | t/z | s/z
fistpl t // 1/z | t/z | s/z
fadds zi8stepu
fxch %st(2)
fadds sdivz8stepu
fxch %st(2)
flds tdivz8stepu
faddp %st(0),%st(2)
flds fp_64k
fdiv %st(1),%st(0) // z = 1/1/z
// this is what we've gone to all this trouble to
// overlap
LFDIVInFlight1:
addl s,%esi
addl t,%edx
movl C(bbextents),%ebx
movl C(bbextentt),%ebp
cmpl %ebx,%esi
ja LClampHighOrLow0
LClampReentry0:
movl %esi,s
movl pbase,%ebx
shll $16,%esi
cmpl %ebp,%edx
movl %esi,sfracf
ja LClampHighOrLow1
LClampReentry1:
movl %edx,t
movl s,%esi // sfrac = scans->sfrac;
shll $16,%edx
movl t,%eax // tfrac = scans->tfrac;
sarl $16,%esi
movl %edx,tfracf
//
// calculate the texture starting address
//
sarl $16,%eax
movl C(cachewidth),%edx
imull %edx,%eax // (tfrac >> 16) * cachewidth
addl %ebx,%esi
addl %eax,%esi // psource = pbase + (sfrac >> 16) +
// ((tfrac >> 16) * cachewidth);
//
// determine whether last span or not
//
cmpl $8,%ecx
jna LLastSegment
//
// not the last segment; do full 8-wide segment
//
LNotLastSegment:
//
// advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
// get there
//
// pick up after the FDIV that was left in flight previously
fld %st(0) // duplicate it
fmul %st(4),%st(0) // s = s/z * z
fxch %st(1)
fmul %st(3),%st(0) // t = t/z * z
fxch %st(1)
fistpl snext
fistpl tnext
movl snext,%eax
movl tnext,%edx
movb (%esi),%bl // get first source texel
subl $8,%ecx // count off this segments' pixels
movl C(sadjust),%ebp
movl %ecx,counttemp // remember count of remaining pixels
movl C(tadjust),%ecx
movb %bl,(%edi) // store first dest pixel
addl %eax,%ebp
addl %edx,%ecx
movl C(bbextents),%eax
movl C(bbextentt),%edx
cmpl $2048,%ebp
jl LClampLow2
cmpl %eax,%ebp
ja LClampHigh2
LClampReentry2:
cmpl $2048,%ecx
jl LClampLow3
cmpl %edx,%ecx
ja LClampHigh3
LClampReentry3:
movl %ebp,snext
movl %ecx,tnext
subl s,%ebp
subl t,%ecx
//
// set up advancetable
//
movl %ecx,%eax
movl %ebp,%edx
sarl $19,%eax // tstep >>= 16;
jz LZero
sarl $19,%edx // sstep >>= 16;
movl C(cachewidth),%ebx
imull %ebx,%eax
jmp LSetUp1
LZero:
sarl $19,%edx // sstep >>= 16;
movl C(cachewidth),%ebx
LSetUp1:
addl %edx,%eax // add in sstep
// (tstep >> 16) * cachewidth + (sstep >> 16);
movl tfracf,%edx
movl %eax,advancetable+4 // advance base in t
addl %ebx,%eax // ((tstep >> 16) + 1) * cachewidth +
// (sstep >> 16);
shll $13,%ebp // left-justify sstep fractional part
movl sfracf,%ebx
shll $13,%ecx // left-justify tstep fractional part
movl %eax,advancetable // advance extra in t
movl %ecx,tstep
addl %ecx,%edx // advance tfrac fractional part by tstep frac
sbbl %ecx,%ecx // turn tstep carry into -1 (0 if none)
addl %ebp,%ebx // advance sfrac fractional part by sstep frac
adcl advancetable+4(,%ecx,4),%esi // point to next source texel
addl tstep,%edx
sbbl %ecx,%ecx
movb (%esi),%al
addl %ebp,%ebx
movb %al,1(%edi)
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,2(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,3(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
//
// start FDIV for end of next segment in flight, so it can overlap
//
movl counttemp,%ecx
cmpl $8,%ecx // more than one segment after this?
ja LSetupNotLast2 // yes
decl %ecx
jz LFDIVInFlight2 // if only one pixel, no need to start an FDIV
movl %ecx,spancountminus1
fildl spancountminus1
flds C(d_zistepu) // C(d_zistepu) | spancountminus1
fmul %st(1),%st(0) // C(d_zistepu)*scm1 | scm1
flds C(d_tdivzstepu) // C(d_tdivzstepu) | C(d_zistepu)*scm1 | scm1
fmul %st(2),%st(0) // C(d_tdivzstepu)*scm1 | C(d_zistepu)*scm1 | scm1
fxch %st(1) // C(d_zistepu)*scm1 | C(d_tdivzstepu)*scm1 | scm1
faddp %st(0),%st(3) // C(d_tdivzstepu)*scm1 | scm1
fxch %st(1) // scm1 | C(d_tdivzstepu)*scm1
fmuls C(d_sdivzstepu) // C(d_sdivzstepu)*scm1 | C(d_tdivzstepu)*scm1
fxch %st(1) // C(d_tdivzstepu)*scm1 | C(d_sdivzstepu)*scm1
faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1
flds fp_64k // 64k | C(d_sdivzstepu)*scm1
fxch %st(1) // C(d_sdivzstepu)*scm1 | 64k
faddp %st(0),%st(4) // 64k
fdiv %st(1),%st(0) // this is what we've gone to all this trouble to
// overlap
jmp LFDIVInFlight2
.align 4
LSetupNotLast2:
fadds zi8stepu
fxch %st(2)
fadds sdivz8stepu
fxch %st(2)
flds tdivz8stepu
faddp %st(0),%st(2)
flds fp_64k
fdiv %st(1),%st(0) // z = 1/1/z
// this is what we've gone to all this trouble to
// overlap
LFDIVInFlight2:
movl %ecx,counttemp
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,4(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,5(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,6(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl $8,%edi
movl %edx,tfracf
movl snext,%edx
movl %ebx,sfracf
movl tnext,%ebx
movl %edx,s
movl %ebx,t
movl counttemp,%ecx // retrieve count
//
// determine whether last span or not
//
cmpl $8,%ecx // are there multiple segments remaining?
movb %al,-1(%edi)
ja LNotLastSegment // yes
//
// last segment of scan
//
LLastSegment:
//
// advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
// get there. The number of pixels left is variable, and we want to land on the
// last pixel, not step one past it, so we can't run into arithmetic problems
//
testl %ecx,%ecx
jz LNoSteps // just draw the last pixel and we're done
// pick up after the FDIV that was left in flight previously
fld %st(0) // duplicate it
fmul %st(4),%st(0) // s = s/z * z
fxch %st(1)
fmul %st(3),%st(0) // t = t/z * z
fxch %st(1)
fistpl snext
fistpl tnext
movb (%esi),%al // load first texel in segment
movl C(tadjust),%ebx
movb %al,(%edi) // store first pixel in segment
movl C(sadjust),%eax
addl snext,%eax
addl tnext,%ebx
movl C(bbextents),%ebp
movl C(bbextentt),%edx
cmpl $2048,%eax
jl LClampLow4
cmpl %ebp,%eax
ja LClampHigh4
LClampReentry4:
movl %eax,snext
cmpl $2048,%ebx
jl LClampLow5
cmpl %edx,%ebx
ja LClampHigh5
LClampReentry5:
cmpl $1,%ecx // don't bother
je LOnlyOneStep // if two pixels in segment, there's only one step,
// of the segment length
subl s,%eax
subl t,%ebx
addl %eax,%eax // convert to 15.17 format so multiply by 1.31
addl %ebx,%ebx // reciprocal yields 16.48
imull reciprocal_table-8(,%ecx,4) // sstep = (snext - s) / (spancount-1)
movl %edx,%ebp
movl %ebx,%eax
imull reciprocal_table-8(,%ecx,4) // tstep = (tnext - t) / (spancount-1)
LSetEntryvec:
//
// set up advancetable
//
movl entryvec_table(,%ecx,4),%ebx
movl %edx,%eax
movl %ebx,jumptemp // entry point into code for RET later
movl %ebp,%ecx
sarl $16,%edx // tstep >>= 16;
movl C(cachewidth),%ebx
sarl $16,%ecx // sstep >>= 16;
imull %ebx,%edx
addl %ecx,%edx // add in sstep
// (tstep >> 16) * cachewidth + (sstep >> 16);
movl tfracf,%ecx
movl %edx,advancetable+4 // advance base in t
addl %ebx,%edx // ((tstep >> 16) + 1) * cachewidth +
// (sstep >> 16);
shll $16,%ebp // left-justify sstep fractional part
movl sfracf,%ebx
shll $16,%eax // left-justify tstep fractional part
movl %edx,advancetable // advance extra in t
movl %eax,tstep
movl %ecx,%edx
addl %eax,%edx
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
jmp *jumptemp // jump to the number-of-pixels handler
//----------------------------------------
LNoSteps:
movb (%esi),%al // load first texel in segment
subl $7,%edi // adjust for hardwired offset
jmp LEndSpan
LOnlyOneStep:
subl s,%eax
subl t,%ebx
movl %eax,%ebp
movl %ebx,%edx
jmp LSetEntryvec
//----------------------------------------
.globl Entry2_8
Entry2_8:
subl $6,%edi // adjust for hardwired offsets
movb (%esi),%al
jmp LLEntry2_8
//----------------------------------------
.globl Entry3_8
Entry3_8:
subl $5,%edi // adjust for hardwired offsets
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
jmp LLEntry3_8
//----------------------------------------
.globl Entry4_8
Entry4_8:
subl $4,%edi // adjust for hardwired offsets
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
jmp LLEntry4_8
//----------------------------------------
.globl Entry5_8
Entry5_8:
subl $3,%edi // adjust for hardwired offsets
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
jmp LLEntry5_8
//----------------------------------------
.globl Entry6_8
Entry6_8:
subl $2,%edi // adjust for hardwired offsets
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
jmp LLEntry6_8
//----------------------------------------
.globl Entry7_8
Entry7_8:
decl %edi // adjust for hardwired offsets
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
jmp LLEntry7_8
//----------------------------------------
.globl Entry8_8
Entry8_8:
addl %eax,%edx
movb (%esi),%al
sbbl %ecx,%ecx
addl %ebp,%ebx
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
sbbl %ecx,%ecx
movb %al,1(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
LLEntry7_8:
sbbl %ecx,%ecx
movb %al,2(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
LLEntry6_8:
sbbl %ecx,%ecx
movb %al,3(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
LLEntry5_8:
sbbl %ecx,%ecx
movb %al,4(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
addl tstep,%edx
LLEntry4_8:
sbbl %ecx,%ecx
movb %al,5(%edi)
addl %ebp,%ebx
movb (%esi),%al
adcl advancetable+4(,%ecx,4),%esi
LLEntry3_8:
movb %al,6(%edi)
movb (%esi),%al
LLEntry2_8:
LEndSpan:
//
// clear s/z, t/z, 1/z from FP stack
//
fstp %st(0)
fstp %st(0)
fstp %st(0)
movl pspantemp,%ebx // restore spans pointer
movl espan_t_pnext(%ebx),%ebx // point to next span
testl %ebx,%ebx // any more spans?
movb %al,7(%edi)
jnz LSpanLoop // more spans
popl %ebx // restore register variables
popl %esi
popl %edi
popl %ebp // restore the caller's stack frame
ret
//----------------------------------------------------------------------
// 8-bpp horizontal span z drawing codefor polygons, with no transparency.
//
// Assumes there is at least one span in pzspans, and that every span
// contains at least one pixel
//----------------------------------------------------------------------
.text
// z-clamp on a non-negative gradient span
LClamp:
movl $0x40000000,%edx
xorl %ebx,%ebx
fstp %st(0)
jmp LZDraw
// z-clamp on a negative gradient span
LClampNeg:
movl $0x40000000,%edx
xorl %ebx,%ebx
fstp %st(0)
jmp LZDrawNeg
#define pzspans 4+16
.globl C(D_DrawZSpans)
C(D_DrawZSpans):
pushl %ebp // preserve caller's stack frame
pushl %edi
pushl %esi // preserve register variables
pushl %ebx
flds C(d_zistepu)
movl C(d_zistepu),%eax
movl pzspans(%esp),%esi
testl %eax,%eax
jz LFNegSpan
fmuls Float2ToThe31nd
fistpl izistep // note: we are relying on FP exceptions being turned
// off here to avoid range problems
movl izistep,%ebx // remains loaded for all spans
LFSpanLoop:
// set up the initial 1/z value
fildl espan_t_v(%esi)
fildl espan_t_u(%esi)
movl espan_t_v(%esi),%ecx
movl C(d_pzbuffer),%edi
fmuls C(d_zistepu)
fxch %st(1)
fmuls C(d_zistepv)
fxch %st(1)
fadds C(d_ziorigin)
imull C(d_zrowbytes),%ecx
faddp %st(0),%st(1)
// clamp if z is nearer than 2 (1/z > 0.5)
fcoms float_point5
addl %ecx,%edi
movl espan_t_u(%esi),%edx
addl %edx,%edx // word count
movl espan_t_count(%esi),%ecx
addl %edx,%edi // pdest = &pdestspan[scans->u];
pushl %esi // preserve spans pointer
fnstsw %ax
testb $0x45,%ah
jz LClamp
fmuls Float2ToThe31nd
fistpl izi // note: we are relying on FP exceptions being turned
// off here to avoid problems when the span is closer
// than 1/(2**31)
movl izi,%edx
// at this point:
// %ebx = izistep
// %ecx = count
// %edx = izi
// %edi = pdest
LZDraw:
// do a single pixel up front, if necessary to dword align the destination
testl $2,%edi
jz LFMiddle
movl %edx,%eax
addl %ebx,%edx
shrl $16,%eax
decl %ecx
movw %ax,(%edi)
addl $2,%edi
// do middle a pair of aligned dwords at a time
LFMiddle:
pushl %ecx
shrl $1,%ecx // count / 2
jz LFLast // no aligned dwords to do
shrl $1,%ecx // (count / 2) / 2
jnc LFMiddleLoop // even number of aligned dwords to do
movl %edx,%eax
addl %ebx,%edx
shrl $16,%eax
movl %edx,%esi
addl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%eax
movl %eax,(%edi)
addl $4,%edi
andl %ecx,%ecx
jz LFLast
LFMiddleLoop:
movl %edx,%eax
addl %ebx,%edx
shrl $16,%eax
movl %edx,%esi
addl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%eax
movl %edx,%ebp
movl %eax,(%edi)
addl %ebx,%edx
shrl $16,%ebp
movl %edx,%esi
addl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%ebp
movl %ebp,4(%edi) // FIXME: eliminate register contention
addl $8,%edi
decl %ecx
jnz LFMiddleLoop
LFLast:
popl %ecx // retrieve count
popl %esi // retrieve span pointer
// do the last, unaligned pixel, if there is one
andl $1,%ecx // is there an odd pixel left to do?
jz LFSpanDone // no
shrl $16,%edx
movw %dx,(%edi) // do the final pixel's z
LFSpanDone:
movl espan_t_pnext(%esi),%esi
testl %esi,%esi
jnz LFSpanLoop
jmp LFDone
LFNegSpan:
fmuls FloatMinus2ToThe31nd
fistpl izistep // note: we are relying on FP exceptions being turned
// off here to avoid range problems
movl izistep,%ebx // remains loaded for all spans
LFNegSpanLoop:
// set up the initial 1/z value
fildl espan_t_v(%esi)
fildl espan_t_u(%esi)
movl espan_t_v(%esi),%ecx
movl C(d_pzbuffer),%edi
fmuls C(d_zistepu)
fxch %st(1)
fmuls C(d_zistepv)
fxch %st(1)
fadds C(d_ziorigin)
imull C(d_zrowbytes),%ecx
faddp %st(0),%st(1)
// clamp if z is nearer than 2 (1/z > 0.5)
fcoms float_point5
addl %ecx,%edi
movl espan_t_u(%esi),%edx
addl %edx,%edx // word count
movl espan_t_count(%esi),%ecx
addl %edx,%edi // pdest = &pdestspan[scans->u];
pushl %esi // preserve spans pointer
fnstsw %ax
testb $0x45,%ah
jz LClampNeg
fmuls Float2ToThe31nd
fistpl izi // note: we are relying on FP exceptions being turned
// off here to avoid problems when the span is closer
// than 1/(2**31)
movl izi,%edx
// at this point:
// %ebx = izistep
// %ecx = count
// %edx = izi
// %edi = pdest
LZDrawNeg:
// do a single pixel up front, if necessary to dword align the destination
testl $2,%edi
jz LFNegMiddle
movl %edx,%eax
subl %ebx,%edx
shrl $16,%eax
decl %ecx
movw %ax,(%edi)
addl $2,%edi
// do middle a pair of aligned dwords at a time
LFNegMiddle:
pushl %ecx
shrl $1,%ecx // count / 2
jz LFNegLast // no aligned dwords to do
shrl $1,%ecx // (count / 2) / 2
jnc LFNegMiddleLoop // even number of aligned dwords to do
movl %edx,%eax
subl %ebx,%edx
shrl $16,%eax
movl %edx,%esi
subl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%eax
movl %eax,(%edi)
addl $4,%edi
andl %ecx,%ecx
jz LFNegLast
LFNegMiddleLoop:
movl %edx,%eax
subl %ebx,%edx
shrl $16,%eax
movl %edx,%esi
subl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%eax
movl %edx,%ebp
movl %eax,(%edi)
subl %ebx,%edx
shrl $16,%ebp
movl %edx,%esi
subl %ebx,%edx
andl $0xFFFF0000,%esi
orl %esi,%ebp
movl %ebp,4(%edi) // FIXME: eliminate register contention
addl $8,%edi
decl %ecx
jnz LFNegMiddleLoop
LFNegLast:
popl %ecx // retrieve count
popl %esi // retrieve span pointer
// do the last, unaligned pixel, if there is one
andl $1,%ecx // is there an odd pixel left to do?
jz LFNegSpanDone // no
shrl $16,%edx
movw %dx,(%edi) // do the final pixel's z
LFNegSpanDone:
movl espan_t_pnext(%esi),%esi
testl %esi,%esi
jnz LFNegSpanLoop
LFDone:
popl %ebx // restore register variables
popl %esi
popl %edi
popl %ebp // restore the caller's stack frame
ret
#endif // id386
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