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Diffstat (limited to 'engines/scumm/gfxARM.s')
| -rwxr-xr-x | engines/scumm/gfxARM.s | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/engines/scumm/gfxARM.s b/engines/scumm/gfxARM.s new file mode 100755 index 0000000000..fa2457fb29 --- /dev/null +++ b/engines/scumm/gfxARM.s @@ -0,0 +1,120 @@ +@ ScummVM Scumm Interpreter +@ Copyright (C) 2007 The ScummVM project +@ +@ 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +@ +@ $URL: $ +@ $Id: $ +@ +@ @author Robin Watts (robin@wss.co.uk) + + .text + + .global asmDrawStripToScreen + + @ ARM implementation of asmDrawStripToScreen. + @ + @ C prototype would be: + @ + @ extern "C" void asmDrawStripToScreen(int height, + @ int width, + @ byte const *text, + @ byte const *src, + @ byte *dst, + @ int vsPitch, + @ int vsScreenWidth, + @ int textSurfacePitch); + @ + @ In addition, we assume that text, src and dst are all word (4 byte) + @ aligned. This is the same assumption that the old 'inline' version + @ made. +asmDrawStripToScreen: + @ r0 = height + @ r1 = width + @ r2 = text + @ r3 = src + MOV r12,r13 + STMFD r13!,{r4-r7,r9-r11,R14} + LDMIA r12,{r4,r5,r6,r7} + @ r4 = dst + @ r5 = vsPitch + @ r6 = vmScreenWidth + @ r7 = textSurfacePitch + + CMP r0,#0 @ If height<=0 + MOVLE r0,#1 @ height=1 + CMP r1,#4 @ If width<4 + BLT end @ return + + @ Width &= ~4 ? What's that about then? Width &= ~3 I could have + @ understood... + BIC r1,r1,#4 + + SUB r5,r5,r1 @ vsPitch -= width + SUB r6,r6,r1 @ vmScreenWidth -= width + SUB r7,r7,r1 @ textSurfacePitch -= width + MOV r10,#253 + ORR r10,r10,r10,LSL #8 + ORR r10,r10,r10,LSL #16 @ r10 = mask +yLoop: + MOV r14,r1 @ r14 = width +xLoop: + LDR r12,[r2],#4 @ r12 = [text] + LDR r11,[r3],#4 @ r11 = [src] + CMP r12,r10 + BNE singleByteCompare + SUBS r14,r14,#4 + STR r11,[r4], #4 @ r4 = [dst] + BGT xLoop + + ADD r2,r2,r7 @ text += textSurfacePitch + ADD r3,r3,r5 @ src += vsPitch + ADD r4,r4,r6 @ dst += vmScreenWidth + SUBS r0,r0,#1 + BGT yLoop + LDMFD r13!,{r4-r7,r9-r11,PC} + +singleByteCompare: + MOV r9,r12,LSR #24 @ r9 = 1st byte of [text] + CMP r9,r10,LSR #24 @ if (r9 == mask) + MOVEQ r9,r11,LSR #24 @ r9 = 1st byte of [src] + ORR r12,r9,r12,LSL #8 @ r12 = combine r9 and r12 + + MOV r9,r12,LSR #24 @ r9 = 1st byte of [text] + CMP r9,r10,LSR #24 @ if (r9 == mask) + MOVEQ r9,r11,LSR #24 @ r9 = 1st byte of [src] + ORR r12,r9,r12,LSL #8 @ r12 = combine r9 and r12 + + MOV r9,r12,LSR #24 @ r9 = 1st byte of [text] + CMP r9,r10,LSR #24 @ if (r9 == mask) + MOVEQ r9,r11,LSR #24 @ r9 = 1st byte of [src] + ORR r12,r9,r12,LSL #8 @ r12 = combine r9 and r12 + + MOV r9,r12,LSR #24 @ r9 = 1st byte of [text] + CMP r9,r10,LSR #24 @ if (r9 == mask) + MOVEQ r9,r11,LSR #24 @ r9 = 1st byte of [src] + ORR r12,r9,r12,LSL #8 @ r12 = combine r9 and r12 + + STR r12,[r4],#4 + SUBS r14,r14,#4 + BGT xLoop + + ADD r2,r2,r7 @ text += textSurfacePitch + ADD r3,r3,r5 @ src += vsPitch + ADD r4,r4,r6 @ dst += vmScreenWidth + SUBS r0,r0,#1 + BGT yLoop +end: + LDMFD r13!,{r4-r7,r9-r11,PC} |