scummvm/backends/platform/wince/smartLandScale.s
2011-05-12 01:16:22 +02:00

188 lines
6.4 KiB
ArmAsm

@ ScummVM - Graphic Adventure Engine
@
@ ScummVM is the legal property of its developers, whose names
@ are too numerous to list here. Please refer to the COPYRIGHT
@ file distributed with this source distribution.
@
@ 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.
@
@ @author Robin Watts (robin@wss.co.uk)
@ For 16 source pixels 0123456789ABCDEF, we want to produce 11 output
@ pixels.
@0000000000011111111111222222222223333333333344444444444555555555
@<------||------><------||------><------||------><------||------>
@5566666666666777777777778888888888899999999999AAAAAAAAAAABBBBBBB
@<------||------><------||------><------||------><------||------>
@BBBBCCCCCCCCCCCDDDDDDDDDDDEEEEEEEEEEEFFFFFFFFFFF
@<------||------><------||------><------||------>
@ So, use the following weights (approximately right)
@ d0 = (3*s0 + 1*s1)>>2 Every source pixel constitutes
@ d1 = (2*s1 + 2*s2)>>2 3/4 of a destination pixel,
@ d2 = (1*s2 + 3*s3)>>2 except for s4,s5,sA and sB which
@ d3 = (2*s4 + 2*s5)>>2 constitute 1/2 each.
@ d4 = (3*s6 + 1*s7)>>2
@ d5 = (2*s7 + 2*s8)>>2
@ d6 = (1*s8 + 3*s9)>>2
@ d7 = (2*sA + 2*sB)>>2
@ d8 = (3*sC + 1*sD)>>2
@ d9 = (2*sD + 2*sE)>>2
@ dA = (1*sE + 3*sF)>>2
.text
.global SmartphoneLandscapeARM
@ scales a width x height block of 16bpp pixels from srcPtr to dstPtr,
@ scaling each scanline down by 11/16ths. Every 8th scanline is dropped
@ srcPitch and dstPitch identify how to reach subsequent lines.
@ mask allows for one routine to do both 565 and 565 formats.
SmartphoneLandscapeARM:
@ r0 = srcPtr
@ r1 = srcSpan
@ r2 = dstPtr
@ r3 = dstSpan
@ <> = width
@ <> = height
@ <> = mask
MOV r12,r13
STMFD r13!,{r4-r11,r14}
LDMFD r12,{r4,r5,r11} @ r4 = width
@ r5 = height
@ r11= mask
MOV r7, #7 @ r7 = line
SUB r8, r1, r4, LSL #1 @ r8 = srcSpan - width*2
y_loop:
MOV r6, r4 @ r6 = i
MOV r9, r2 @ r9 = dstPtr
x_loop:
LDRH r14,[r0],#2 @ r14 = s0
LDRH r12,[r0],#2 @ r12 = s1
LDRH r10,[r0],#2 @ r10 = s2
ORR r14,r14,r14,LSL #16 @ r14 = s0s0
ORR r12,r12,r12,LSL #16 @ r12 = s1s1
AND r14,r14,r11 @ r14 = s0 as g_b_r
AND r12,r12,r11 @ r12 = s1 as g_b_r
ADD r14,r14,r14,LSL #1 @ r14 = s0*3 as g_b_r
ORR r10,r10,r10,LSL #16 @ r10 = s2s2
ADD r14,r14,r12 @ r14 = (s0*3 + s1) as g_b_r
AND r10,r10,r11 @ r10 = s2 as g_b_r
AND r14,r11,r14,LSR #2 @ r14 = d0 as g_b_r
ORR r14,r14,r14,LSR #16 @ r14 = d0
STRH r14,[r9],#2 @ store d0
ADD r12,r12,r10 @ r12 = (s1 + s2) as g_b_r
LDRH r14,[r0],#2 @ r14 = s3
AND r12,r11,r12,LSR #1 @ r12 = d1 as g_b_r
ORR r12,r12,r12,LSR #16 @ r12 = d1
STRH r12,[r9],#2 @ store d1
ORR r14,r14,r14,LSL #16 @ r14 = s3s3
AND r14,r14,r11 @ r14 = s3 as g_b_r
ADD r10,r10,r14 @ r10 = (s2 + s3) as g_b_r
ADD r10,r10,r14,LSL #1 @ r10 = (s2 + s3*3) as g_b_r
LDRH r14,[r0],#2 @ r14 = s4
LDRH r12,[r0],#2 @ r12 = s5
AND r10,r11,r10,LSR #2 @ r10 = d2 as g_b_r
ORR r10,r10,r10,LSR #16 @ r10 = d2
STRH r10,[r9],#2 @ store d2
ORR r14,r14,r14,LSL #16 @ r14 = s4s4
ORR r12,r12,r12,LSL #16 @ r12 = s5s5
AND r14,r14,r11 @ r14 = s4 as g_b_r
AND r12,r12,r11 @ r12 = s5 as g_b_r
ADD r14,r14,r12 @ r14 = (s4 + s5) as g_b_r
LDRH r12,[r0],#2 @ r12 = s6
LDRH r10,[r0],#2 @ r10 = s7
AND r14,r11,r14,LSR #1 @ r14 = d3 as g_b_r
ORR r14,r14,r14,LSR #16 @ r14 = d3
STRH r14,[r9],#2 @ store d3
ORR r12,r12,r12,LSL #16 @ r12 = s6s6
ORR r10,r10,r10,LSL #16 @ r10 = s7s7
LDRH r14,[r0],#2 @ r14 = s8
AND r12,r12,r11 @ r12 = s6 as g_b_r
AND r10,r10,r11 @ r10 = s7 as g_b_r
ORR r14,r14,r14,LSL #16 @ r14 = s8s8
ADD r12,r12,r12,LSL #1 @ r12 = 3*s6 as g_b_r
AND r14,r14,r11 @ r14 = s8 as g_b_r
ADD r12,r12,r10 @ r12 = (3*s6+s7) as g_b_r
AND r12,r11,r12,LSR #2 @ r12 = d4 as g_b_r
ORR r12,r12,r12,LSR #16 @ r12 = d4
STRH r12,[r9],#2 @ store d4
ADD r10,r10,r14 @ r10 = (s7+s8) as g_b_r
AND r10,r11,r10,LSR #1 @ r10 = d5 as g_b_r
LDRH r12,[r0],#2 @ r12 = s9
ORR r10,r10,r10,LSR #16 @ r10 = d5
STRH r10,[r9],#2 @ store d5
ORR r12,r12,r12,LSL #16 @ r12 = s9s9
AND r12,r12,r11 @ r12 = s9 as g_b_r
ADD r12,r12,r12,LSL #1 @ r12 = s9*3 as g_b_r
ADD r12,r12,r14 @ r12 = (s8+s9*3) as g_b_r
AND r12,r11,r12,LSR #2 @ r12 = d6 as g_b_r
LDRH r14,[r0],#2 @ r14 = sA
LDRH r10,[r0],#2 @ r10 = sB
ORR r12,r12,r12,LSR #16 @ r12 = d6
STRH r12,[r9],#2 @ store d6
ORR r14,r14,r14,LSL #16 @ r14 = sAsA
ORR r10,r10,r10,LSL #16 @ r10 = sBsB
LDRH r12,[r0],#2 @ r12 = sC
AND r14,r14,r11 @ r14 = sA as g_b_r
AND r10,r10,r11 @ r10 = sB as g_b_r
ORR r12,r12,r12,LSL #16 @ r12 = sCsC
ADD r14,r14,r10 @ r14 = (sA + sB) as g_b_r
LDRH r10,[r0],#2 @ r10 = sD
AND r14,r11,r14,LSR #1 @ r14 = d7 as g_b_r
AND r12,r12,r11 @ r12 = sC as g_b_r
ORR r14,r14,r14,LSR #16 @ r14 = d7
ORR r10,r10,r10,LSL #16 @ r10 = sDsD
STRH r14,[r9],#2 @ store d7
AND r10,r10,r11 @ r10 = sD as g_b_r
ADD r12,r12,r12,LSL #1 @ r12 = 3*sC as g_b_r
LDRH r14,[r0],#2 @ r14 = sE
ADD r12,r12,r10 @ r12 = (3*sC+sD) as g_b_r
AND r12,r11,r12,LSR #2 @ r12 = d8 as g_b_r
ORR r14,r14,r14,LSL #16 @ r14 = sEsE
ORR r12,r12,r12,LSR #16 @ r12 = d8
AND r14,r14,r11 @ r14 = sE as g_b_r
STRH r12,[r9],#2 @ store d8
ADD r10,r10,r14 @ r10 = (sD+sE) as g_b_r
LDRH r12,[r0],#2 @ r12 = sF
AND r10,r11,r10,LSR #1 @ r10 = d9 as g_b_r
ORR r10,r10,r10,LSR #16 @ r10 = d9
STRH r10,[r9],#2 @ store d9
ORR r12,r12,r12,LSL #16 @ r12 = sFsF
AND r12,r12,r11 @ r12 = sF as g_b_r
ADD r12,r12,r12,LSL #1 @ r12 = 3*sF as g_b_r
ADD r12,r12,r14 @ r12 = (sE+3*sF) as g_b_r
AND r12,r11,r12,LSR #2 @ r12 = dA as g_b_r
ORR r12,r12,r12,LSR #16 @ r12 = dA
SUBS r6,r6,#16 @ width -= 16
STRH r12,[r9],#2 @ store dA
BGT x_loop
ADD r0, r0, r8 @ srcPtr += srcSpan
ADD r2, r2, r3 @ dstPtr += dstSpan
SUBS r7, r7, #1
ADDEQ r0, r0, r1
MOVEQ r7, #7
SUBEQ r5, r5, #1
SUBS r5, r5, #1
BGT y_loop
LDMFD r13!,{r4-r11,PC}