| /*
|
| Copyright (C) 1996-1997 Id Software, Inc.
|
|
|
| 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_spr8.s |
| // x86 assembly-language horizontal 8-bpp transparent span-drawing code. |
| // |
| |
| #include "asm_i386.h" |
| #include "quakeasm.h" |
| #include "asm_draw.h" |
| |
| #if id386 |
| |
| //---------------------------------------------------------------------- |
| // 8-bpp horizontal span drawing code for polygons, with transparency. |
| //---------------------------------------------------------------------- |
| |
| .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_SpriteDrawSpans) |
| C(D_SpriteDrawSpans): |
| 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, and 1/z step in 0.32 fixed-point |
| // |
| // FIXME: 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 |
| flds C(d_zistepu) |
| fmuls fp_64kx64k |
| fxch %st(3) |
| fstps sdivz8stepu |
| fstps zi8stepu |
| fstps tdivz8stepu |
| fistpl izistep |
| movl izistep,%eax |
| rorl $16,%eax // put upper 16 bits in low word |
| movl sspan_t_count(%ebx),%ecx |
| movl %eax,izistep |
| |
| cmpl $0,%ecx |
| jle LNextSpan |
| |
| 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 sspan_t_v(%ebx) |
| fildl sspan_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 |
| |
| fld %st(0) // FIXME: get rid of stall on FMUL? |
| fmuls fp_64kx64k |
| fxch %st(1) |
| |
| // |
| // calculate and clamp s & t |
| // |
| fdivr %st(0),%st(2) // 1/z | z*64k | t/z | s/z |
| fxch %st(1) |
| |
| fistpl izi // 0.32 fixed-point 1/z |
| movl izi,%ebp |
| |
| // |
| // set pz to point to the first z-buffer pixel in the span |
| // |
| rorl $16,%ebp // put upper 16 bits in low word |
| movl sspan_t_v(%ebx),%eax |
| movl %ebp,izi |
| movl sspan_t_u(%ebx),%ebp |
| imull C(d_zrowbytes) |
| shll $1,%ebp // a word per pixel |
| addl C(d_pzbuffer),%eax |
| addl %ebp,%eax |
| movl %eax,pz |
| |
| // |
| // point %edi to the first pixel in the span |
| // |
| movl C(d_viewbuffer),%ebp |
| movl sspan_t_v(%ebx),%eax |
| pushl %ebx // preserve spans pointer |
| movl C(tadjust),%edx |
| movl C(sadjust),%esi |
| movl C(d_scantable)(,%eax,4),%edi // v * screenwidth |
| addl %ebp,%edi |
| movl sspan_t_u(%ebx),%ebp |
| addl %ebp,%edi // pdest = &pdestspan[scans->u]; |
| |
| // |
| // 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) // _d_tdivzstepu | spancountminus1 |
| flds C(d_zistepu) // _d_zistepu | _d_tdivzstepu | spancountminus1 |
| fmul %st(2),%st(0) // _d_zistepu*scm1 | _d_tdivzstepu | scm1 |
| fxch %st(1) // _d_tdivzstepu | _d_zistepu*scm1 | scm1 |
| fmul %st(2),%st(0) // _d_tdivzstepu*scm1 | _d_zistepu*scm1 | scm1 |
| fxch %st(2) // scm1 | _d_zistepu*scm1 | _d_tdivzstepu*scm1 |
| fmuls C(d_sdivzstepu) // _d_sdivzstepu*scm1 | _d_zistepu*scm1 | |
| // _d_tdivzstepu*scm1 |
| fxch %st(1) // _d_zistepu*scm1 | _d_sdivzstepu*scm1 | |
| // _d_tdivzstepu*scm1 |
| faddp %st(0),%st(3) // _d_sdivzstepu*scm1 | _d_tdivzstepu*scm1 |
| fxch %st(1) // _d_tdivzstepu*scm1 | _d_sdivzstepu*scm1 |
| faddp %st(0),%st(3) // _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 |
| addl %ebx,%esi |
| imull C(cachewidth),%eax // (tfrac >> 16) * cachewidth |
| 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 |
| |
| subl $8,%ecx // count off this segments' pixels |
| movl C(sadjust),%ebp |
| pushl %ecx // remember count of remaining pixels |
| movl C(tadjust),%ecx |
| |
| 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,%edx // sstep >>= 16; |
| movl C(cachewidth),%ebx |
| sarl $19,%eax // tstep >>= 16; |
| jz LIsZero |
| imull %ebx,%eax // (tstep >> 16) * cachewidth; |
| LIsZero: |
| 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 %ebp,sstep |
| movl sfracf,%ebx |
| shll $13,%ecx // left-justify tstep fractional part |
| movl %eax,advancetable // advance extra in t |
| movl %ecx,tstep |
| |
| movl pz,%ecx |
| movl izi,%ebp |
| |
| cmpw (%ecx),%bp |
| jl Lp1 |
| movb (%esi),%al // get first source texel |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp1 |
| movw %bp,(%ecx) |
| movb %al,(%edi) // store first dest pixel |
| Lp1: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx // advance tfrac fractional part by tstep frac |
| |
| sbbl %eax,%eax // turn tstep carry into -1 (0 if none) |
| addl sstep,%ebx // advance sfrac fractional part by sstep frac |
| adcl advancetable+4(,%eax,4),%esi // point to next source texel |
| |
| cmpw 2(%ecx),%bp |
| jl Lp2 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp2 |
| movw %bp,2(%ecx) |
| movb %al,1(%edi) |
| Lp2: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| cmpw 4(%ecx),%bp |
| jl Lp3 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp3 |
| movw %bp,4(%ecx) |
| movb %al,2(%edi) |
| Lp3: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| cmpw 6(%ecx),%bp |
| jl Lp4 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp4 |
| movw %bp,6(%ecx) |
| movb %al,3(%edi) |
| Lp4: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| cmpw 8(%ecx),%bp |
| jl Lp5 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp5 |
| movw %bp,8(%ecx) |
| movb %al,4(%edi) |
| Lp5: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| // |
| // start FDIV for end of next segment in flight, so it can overlap |
| // |
| popl %eax |
| cmpl $8,%eax // more than one segment after this? |
| ja LSetupNotLast2 // yes |
| |
| decl %eax |
| jz LFDIVInFlight2 // if only one pixel, no need to start an FDIV |
| movl %eax,spancountminus1 |
| fildl spancountminus1 |
| |
| flds C(d_zistepu) // _d_zistepu | spancountminus1 |
| fmul %st(1),%st(0) // _d_zistepu*scm1 | scm1 |
| flds C(d_tdivzstepu) // _d_tdivzstepu | _d_zistepu*scm1 | scm1 |
| fmul %st(2),%st(0) // _d_tdivzstepu*scm1 | _d_zistepu*scm1 | scm1 |
| fxch %st(1) // _d_zistepu*scm1 | _d_tdivzstepu*scm1 | scm1 |
| faddp %st(0),%st(3) // _d_tdivzstepu*scm1 | scm1 |
| fxch %st(1) // scm1 | _d_tdivzstepu*scm1 |
| fmuls C(d_sdivzstepu) // _d_sdivzstepu*scm1 | _d_tdivzstepu*scm1 |
| fxch %st(1) // _d_tdivzstepu*scm1 | _d_sdivzstepu*scm1 |
| faddp %st(0),%st(3) // _d_sdivzstepu*scm1 |
| flds fp_64k // 64k | _d_sdivzstepu*scm1 |
| fxch %st(1) // _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: |
| pushl %eax |
| |
| cmpw 10(%ecx),%bp |
| jl Lp6 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp6 |
| movw %bp,10(%ecx) |
| movb %al,5(%edi) |
| Lp6: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| cmpw 12(%ecx),%bp |
| jl Lp7 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp7 |
| movw %bp,12(%ecx) |
| movb %al,6(%edi) |
| Lp7: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| cmpw 14(%ecx),%bp |
| jl Lp8 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp8 |
| movw %bp,14(%ecx) |
| movb %al,7(%edi) |
| Lp8: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| addl $8,%edi |
| addl $16,%ecx |
| movl %edx,tfracf |
| movl snext,%edx |
| movl %ebx,sfracf |
| movl tnext,%ebx |
| movl %edx,s |
| movl %ebx,t |
| |
| movl %ecx,pz |
| movl %ebp,izi |
| |
| popl %ecx // retrieve count |
| |
| // |
| // determine whether last span or not |
| // |
| cmpl $8,%ecx // are there multiple segments remaining? |
| 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 |
| |
| movl C(tadjust),%ebx |
| 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 spr8entryvec_table(,%ecx,4),%ebx |
| movl %edx,%eax |
| pushl %ebx // entry point into code for RET later |
| movl %ebp,%ecx |
| sarl $16,%ecx // sstep >>= 16; |
| movl C(cachewidth),%ebx |
| sarl $16,%edx // tstep >>= 16; |
| jz LIsZeroLast |
| imull %ebx,%edx // (tstep >> 16) * cachewidth; |
| LIsZeroLast: |
| 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 %ebp,sstep |
| movl %ecx,%edx |
| |
| movl pz,%ecx |
| movl izi,%ebp |
| |
| ret // jump to the number-of-pixels handler |
| |
| //---------------------------------------- |
| |
| LNoSteps: |
| movl pz,%ecx |
| subl $7,%edi // adjust for hardwired offset |
| subl $14,%ecx |
| jmp LEndSpan |
| |
| |
| LOnlyOneStep: |
| subl s,%eax |
| subl t,%ebx |
| movl %eax,%ebp |
| movl %ebx,%edx |
| jmp LSetEntryvec |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry2_8 |
| Spr8Entry2_8: |
| subl $6,%edi // adjust for hardwired offsets |
| subl $12,%ecx |
| movb (%esi),%al |
| jmp LLEntry2_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry3_8 |
| Spr8Entry3_8: |
| subl $5,%edi // adjust for hardwired offsets |
| subl $10,%ecx |
| jmp LLEntry3_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry4_8 |
| Spr8Entry4_8: |
| subl $4,%edi // adjust for hardwired offsets |
| subl $8,%ecx |
| jmp LLEntry4_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry5_8 |
| Spr8Entry5_8: |
| subl $3,%edi // adjust for hardwired offsets |
| subl $6,%ecx |
| jmp LLEntry5_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry6_8 |
| Spr8Entry6_8: |
| subl $2,%edi // adjust for hardwired offsets |
| subl $4,%ecx |
| jmp LLEntry6_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry7_8 |
| Spr8Entry7_8: |
| decl %edi // adjust for hardwired offsets |
| subl $2,%ecx |
| jmp LLEntry7_8 |
| |
| //---------------------------------------- |
| |
| .globl Spr8Entry8_8 |
| Spr8Entry8_8: |
| cmpw (%ecx),%bp |
| jl Lp9 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp9 |
| movw %bp,(%ecx) |
| movb %al,(%edi) |
| Lp9: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry7_8: |
| cmpw 2(%ecx),%bp |
| jl Lp10 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp10 |
| movw %bp,2(%ecx) |
| movb %al,1(%edi) |
| Lp10: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry6_8: |
| cmpw 4(%ecx),%bp |
| jl Lp11 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp11 |
| movw %bp,4(%ecx) |
| movb %al,2(%edi) |
| Lp11: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry5_8: |
| cmpw 6(%ecx),%bp |
| jl Lp12 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp12 |
| movw %bp,6(%ecx) |
| movb %al,3(%edi) |
| Lp12: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry4_8: |
| cmpw 8(%ecx),%bp |
| jl Lp13 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp13 |
| movw %bp,8(%ecx) |
| movb %al,4(%edi) |
| Lp13: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry3_8: |
| cmpw 10(%ecx),%bp |
| jl Lp14 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp14 |
| movw %bp,10(%ecx) |
| movb %al,5(%edi) |
| Lp14: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| LLEntry2_8: |
| cmpw 12(%ecx),%bp |
| jl Lp15 |
| movb (%esi),%al |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp15 |
| movw %bp,12(%ecx) |
| movb %al,6(%edi) |
| Lp15: |
| addl izistep,%ebp |
| adcl $0,%ebp |
| addl tstep,%edx |
| sbbl %eax,%eax |
| addl sstep,%ebx |
| adcl advancetable+4(,%eax,4),%esi |
| |
| LEndSpan: |
| cmpw 14(%ecx),%bp |
| jl Lp16 |
| movb (%esi),%al // load first texel in segment |
| cmpb $(TRANSPARENT_COLOR),%al |
| jz Lp16 |
| movw %bp,14(%ecx) |
| movb %al,7(%edi) |
| Lp16: |
| |
| // |
| // clear s/z, t/z, 1/z from FP stack |
| // |
| fstp %st(0) |
| fstp %st(0) |
| fstp %st(0) |
| |
| popl %ebx // restore spans pointer |
| LNextSpan: |
| addl $(sspan_t_size),%ebx // point to next span |
| movl sspan_t_count(%ebx),%ecx |
| cmpl $0,%ecx // any more spans? |
| jg LSpanLoop // yes |
| jz LNextSpan // yes, but this one's empty |
| |
| popl %ebx // restore register variables |
| popl %esi |
| popl %edi |
| popl %ebp // restore the caller's stack frame |
| ret |
| |
| #endif // id386 |
