The Quake sources as originally release under the GPL license on December 21, 1999

WinQuake/surf16.s

@@ -0,0 +1,172 @@
+/*
+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.
+
+*/
+//
+// surf16.s
+// x86 assembly-language 16 bpp surface block drawing code.
+//
+
+#include "asm_i386.h"
+#include "quakeasm.h"
+#include "asm_draw.h"
+
+#if id386
+
+//----------------------------------------------------------------------
+// Surface block drawer
+//----------------------------------------------------------------------
+
+	.data
+
+k:			.long	0
+loopentry:	.long	0
+
+	.align	4
+blockjumptable16:
+	.long	LEnter2_16
+	.long	LEnter4_16
+	.long	0, LEnter8_16
+	.long	0, 0, 0, LEnter16_16
+
+
+	.text
+
+	.align 4
+.globl C(R_Surf16Start)
+C(R_Surf16Start):
+
+	.align 4
+.globl C(R_DrawSurfaceBlock16)
+C(R_DrawSurfaceBlock16):
+	pushl	%ebp				// preserve caller's stack frame
+	pushl	%edi
+	pushl	%esi				// preserve register variables
+	pushl	%ebx
+
+	movl	C(blocksize),%eax
+	movl	C(prowdestbase),%edi
+	movl	C(pbasesource),%esi
+	movl	C(sourcesstep),%ebx
+	movl	blockjumptable16-4(,%eax,2),%ecx
+	movl	%eax,k
+	movl	%ecx,loopentry
+	movl	C(lightleft),%edx
+	movl	C(lightright),%ebp
+
+Lblockloop16:
+
+	subl	%edx,%ebp
+	movb	C(blockdivshift),%cl
+	sarl	%cl,%ebp
+	jns		Lp1_16
+	testl	C(blockdivmask),%ebp
+	jz		Lp1_16
+	incl	%ebp
+Lp1_16:
+
+	subl	%eax,%eax
+	subl	%ecx,%ecx	// high words must be 0 in loop for addressing
+
+	jmp		*loopentry
+
+	.align	4
+
+#include "block16.h"
+
+	movl	C(pbasesource),%esi
+	movl	C(lightleft),%edx
+	movl	C(lightright),%ebp
+	movl	C(sourcetstep),%eax
+	movl	C(lightrightstep),%ecx
+	movl	C(prowdestbase),%edi
+
+	addl	%eax,%esi
+	addl	%ecx,%ebp
+
+	movl	C(lightleftstep),%eax
+	movl	C(surfrowbytes),%ecx
+
+	addl	%eax,%edx
+	addl	%ecx,%edi
+
+	movl	%esi,C(pbasesource)
+	movl	%ebp,C(lightright)
+	movl	k,%eax
+	movl	%edx,C(lightleft)
+	decl	%eax
+	movl	%edi,C(prowdestbase)
+	movl	%eax,k
+	jnz		Lblockloop16
+
+	popl	%ebx				// restore register variables
+	popl	%esi
+	popl	%edi
+	popl	%ebp				// restore the caller's stack frame
+	ret
+
+.globl C(R_Surf16End)
+C(R_Surf16End):
+
+//----------------------------------------------------------------------
+// Code patching routines
+//----------------------------------------------------------------------
+	.data
+
+	.align 4
+LPatchTable16:
+	.long	LBPatch0-4
+	.long	LBPatch1-4
+	.long	LBPatch2-4
+	.long	LBPatch3-4
+	.long	LBPatch4-4
+	.long	LBPatch5-4
+	.long	LBPatch6-4
+	.long	LBPatch7-4
+	.long	LBPatch8-4
+	.long	LBPatch9-4
+	.long	LBPatch10-4
+	.long	LBPatch11-4
+	.long	LBPatch12-4
+	.long	LBPatch13-4
+	.long	LBPatch14-4
+	.long	LBPatch15-4
+
+	.text
+
+	.align 4
+.globl C(R_Surf16Patch)
+C(R_Surf16Patch):
+	pushl	%ebx
+
+	movl	C(colormap),%eax
+	movl	$LPatchTable16,%ebx
+	movl	$16,%ecx
+LPatchLoop16:
+	movl	(%ebx),%edx
+	addl	$4,%ebx
+	movl	%eax,(%edx)
+	decl	%ecx
+	jnz		LPatchLoop16
+
+	popl	%ebx
+
+	ret
+
+
+#endif	// id386