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SDL_ataric2p.S
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2009 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library 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
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
slouken@libsdl.org
*/
/*
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Chunky to planar conversion routine
1 byte/pixel -> 4 or 8 bit planes
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Patrice Mandin
Xavier Joubert
Mikael Kalms
*/
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.globl _SDL_Atari_C2pConvert
.globl _SDL_Atari_C2pConvert8
.globl _SDL_Atari_C2pConvert4
.globl _SDL_Atari_C2pConvert4_pal
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/* ------------ Conversion C2P, 8 bits ------------ */
.text
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_SDL_Atari_C2pConvert8:
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movel sp@(4),c2p_source
movel sp@(8),c2p_dest
movel sp@(12),c2p_width
movel sp@(16),c2p_height
movel sp@(20),c2p_dblligne
movel sp@(24),c2p_srcpitch
movel sp@(28),c2p_dstpitch
moveml d2-d7/a2-a6,sp@-
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movel c2p_source,c2p_cursrc
movel c2p_dest,c2p_curdst
movel #0x0f0f0f0f,d4
movel #0x00ff00ff,d5
movel #0x55555555,d6
movew c2p_height+2,c2p_row
movew c2p_width+2,d0
andw #-8,d0
movew d0,c2p_rowlen
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SDL_Atari_C2p8_rowloop:
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movel c2p_cursrc,a0
movel c2p_curdst,a1
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movel a0,a2
addw c2p_rowlen,a2
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movel a0@+,d0
movel a0@+,d1
movel a0@+,d2
movel a0@+,d3
/*
d0 = a7a6a5a4a3a2a1a0 b7b6b5b4b3b2b1b0 c7c6c5c4c3c2c1c0 d7d6d5d4d3d2d1d0
d1 = e7e6e5e4e3e2e1e0 f7f6f5f4f3f2f1f0 g7g6g5g4g3g2g1g0 h7h6h5h4h3h2h1h0
d2 = i7i6i5i4i3i2i1i0 j7j6j5j4j3j2j1j0 k7k6k5k4k3k2k1k0 l7l6l5l4l3l2l1l0
d3 = m7m6m5m4m3m2m1m0 n7n6n5n4n3n2n1n0 o7o6o5o4o3o2o1o0 p7p6p5p4p3p2p1p0
*/
movel d1,d7
lsrl #4,d7
eorl d0,d7
andl d4,d7
eorl d7,d0
lsll #4,d7
eorl d7,d1
movel d3,d7
lsrl #4,d7
eorl d2,d7
andl d4,d7
eorl d7,d2
lsll #4,d7
eorl d7,d3
movel d2,d7
lsrl #8,d7
eorl d0,d7
andl d5,d7
eorl d7,d0
lsll #8,d7
eorl d7,d2
movel d3,d7
lsrl #8,d7
eorl d1,d7
andl d5,d7
eorl d7,d1
lsll #8,d7
eorl d7,d3
/*
d0 = a7a6a5a4e7e6e5e4 i7i6i5i4m7m6m5m4 c7c6c5c4g7g6g5g4 k7k6k5k4o7o6o5o4
d1 = a3a2a1a0e3e2e1e0 i3i2i1i0m3m2m1m0 c3c2c1c0g3g2g1g0 k3k2k1k0o3o2o1o0
d2 = b7b6b5b4f7f6f5f4 j7j6j5j4n7n6n5n4 d7d6d5d4h7h6h5h4 l7l6l5l4p7p6p5p4
d3 = b3b2b1b0f3f2f1f0 j3j2j1j0n3n2n1n0 d3d2d1d0h3h2h1h0 l3l2l1l0p3p2p1p0
*/
bras SDL_Atari_C2p8_start
SDL_Atari_C2p8_pix16:
movel a0@+,d0
movel a0@+,d1
movel a0@+,d2
movel a0@+,d3
/*
d0 = a7a6a5a4a3a2a1a0 b7b6b5b4b3b2b1b0 c7c6c5c4c3c2c1c0 d7d6d5d4d3d2d1d0
d1 = e7e6e5e4e3e2e1e0 f7f6f5f4f3f2f1f0 g7g6g5g4g3g2g1g0 h7h6h5h4h3h2h1h0
d2 = i7i6i5i4i3i2i1i0 j7j6j5j4j3j2j1j0 k7k6k5k4k3k2k1k0 l7l6l5l4l3l2l1l0
d3 = m7m6m5m4m3m2m1m0 n7n6n5n4n3n2n1n0 o7o6o5o4o3o2o1o0 p7p6p5p4p3p2p1p0
*/
movel d1,d7
lsrl #4,d7
movel a3,a1@+
eorl d0,d7
andl d4,d7
eorl d7,d0
lsll #4,d7
eorl d7,d1
movel d3,d7
lsrl #4,d7
eorl d2,d7
andl d4,d7
eorl d7,d2
movel a4,a1@+
lsll #4,d7
eorl d7,d3
movel d2,d7
lsrl #8,d7
eorl d0,d7
andl d5,d7
eorl d7,d0
movel a5,a1@+
lsll #8,d7
eorl d7,d2
movel d3,d7
lsrl #8,d7
eorl d1,d7
andl d5,d7
eorl d7,d1
movel a6,a1@+
lsll #8,d7
eorl d7,d3
/*
d0 = a7a6a5a4e7e6e5e4 i7i6i5i4m7m6m5m4 c7c6c5c4g7g6g5g4 k7k6k5k4o7o6o5o4
d1 = a3a2a1a0e3e2e1e0 i3i2i1i0m3m2m1m0 c3c2c1c0g3g2g1g0 k3k2k1k0o3o2o1o0
d2 = b7b6b5b4f7f6f5f4 j7j6j5j4n7n6n5n4 d7d6d5d4h7h6h5h4 l7l6l5l4p7p6p5p4
d3 = b3b2b1b0f3f2f1f0 j3j2j1j0n3n2n1n0 d3d2d1d0h3h2h1h0 l3l2l1l0p3p2p1p0
*/
SDL_Atari_C2p8_start:
movel d2,d7
lsrl #1,d7
eorl d0,d7
andl d6,d7
eorl d7,d0
addl d7,d7
eorl d7,d2
movel d3,d7
lsrl #1,d7
eorl d1,d7
andl d6,d7
eorl d7,d1
addl d7,d7
eorl d7,d3
/*
d0 = a7b7a5b5e7f7e5f5 i7j7i5j5m7n7m5n5 c7d7c5d5g7h7g5h5 k7l7k5l5o7p7o5p5
d1 = a3b3a1b1e3f3e1f1 i3j3i1j1m3n3m1n1 c3d3c1d1g3h3g1h1 k3l3k1l1o3p3o1p1
d2 = a6b6a4b4e6f6e4f4 i6j6i4j4m6n6m4n4 c6d6c4d4g6h6g4h4 k6l6k4l4o6p6o4p4
d3 = a2b2a0b0e2f2e0f0 i2j2i0j0m2n2m0n0 c2d2c0d0g2h2g0h0 k2l2k0l0o2p2o0p0
*/
movew d2,d7
movew d0,d2
swap d2
movew d2,d0
movew d7,d2
movew d3,d7
movew d1,d3
swap d3
movew d3,d1
movew d7,d3
/*
d0 = a7b7a5b5e7f7e5f5 i7j7i5j5m7n7m5n5 a6b6a4b4e6f6e4f4 i6j6i4j4m6n6m4n4
d1 = a3b3a1b1e3f3e1f1 i3j3i1j1m3n3m1n1 a2b2a0b0e2f2e0f0 i2j2i0j0m2n2m0n0
d2 = c7d7c5d5g7h7g5h5 k7l7k5l5o7p7o5p5 c6d6c4d4g6h6g4h4 k6l6k4l4o6p6o4p4
d3 = c3d3c1d1g3h3g1h1 k3l3k1l1o3p3o1p1 c2d2c0d0g2h2g0h0 k2l2k0l0o2p2o0p0
*/
movel d2,d7
lsrl #2,d7
eorl d0,d7
andl #0x33333333,d7
eorl d7,d0
lsll #2,d7
eorl d7,d2
movel d3,d7
lsrl #2,d7
eorl d1,d7
andl #0x33333333,d7
eorl d7,d1
lsll #2,d7
eorl d7,d3
/*
d0 = a7b7c7d7e7f7g7h7 i7j7k7l7m7n7o7p7 a6b6c6d6e6f6g6h6 i6j6k6l6m6n6o6p6
d1 = a3b3c3d3e3f3g3h3 i3j3k3l3m3n3o3p3 a2b2c2d2e2f2g2h2 i2j2k2l2m2n2o2p2
d2 = a5b5c5d5e5f5g5h5 i5j5k5l5m5n5o5p5 a4b4c4d4e4f4g4h4 i4j4k4l4m4n4o4p4
d3 = a1b1c1d1e1f1g1h1 i1j1k1l1m1n1o1p1 a0b0c0d0e0f0g0h0 i0j0k0l0m0n0o0p0
*/
swap d0
swap d1
swap d2
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swap d3
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movel d0,a6
movel d2,a5
movel d1,a4
movel d3,a3
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cmpl a0,a2
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bgt SDL_Atari_C2p8_pix16
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movel a3,a1@+
movel a4,a1@+
movel a5,a1@+
movel a6,a1@+
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/* Double the line ? */
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movel c2p_srcpitch,d0
movel c2p_dstpitch,d1
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tstl c2p_dblligne
beqs SDL_Atari_C2p8_nodblline
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movel c2p_curdst,a0
movel a0,a1
addl d1,a1
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movew c2p_width+2,d7
lsrw #4,d7
subql #1,d7
SDL_Atari_C2p8_dblloop:
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
dbra d7,SDL_Atari_C2p8_dblloop
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addl d1,c2p_curdst
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SDL_Atari_C2p8_nodblline:
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/* Next line */
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addl d0,c2p_cursrc
addl d1,c2p_curdst
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subqw #1,c2p_row
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bne SDL_Atari_C2p8_rowloop
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moveml sp@+,d2-d7/a2-a6
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rts
/* ------------ Conversion C2P, 4 bits ------------ */
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_SDL_Atari_C2pConvert4:
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movel sp@(4),c2p_source
movel sp@(8),c2p_dest
movel sp@(12),c2p_width
movel sp@(16),c2p_height
movel sp@(20),c2p_dblligne
movel sp@(24),c2p_srcpitch
movel sp@(28),c2p_dstpitch
moveml d2-d7/a2-a6,sp@-
movel c2p_source,a0
movel c2p_dest,a1
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lea _SDL_Atari_table_c2p,a2
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movel #0x00070001,d3
#if defined(__M68020__)
moveq #0,d0
#endif
movel c2p_height,d7
subql #1,d7
c2p4_bcly:
movel a0,a4 | Save start address of source
movel a1,a5 | Save start address of dest
| Conversion
movel c2p_width,d6
lsrw #4,d6
subql #1,d6
c2p4_bclx:
| Octets 0-7
moveq #0,d1
moveq #7,d5
c2p4_bcl07:
#if defined(__M68020__)
moveb a0@+,d0
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lea a2@(0,d0:w:4),a3
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#else
moveq #0,d0
moveb a0@+,d0
lslw #2,d0
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lea a2@(0,d0:w),a3
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#endif
lsll #1,d1
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orl a3@,d1
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dbra d5,c2p4_bcl07
movepl d1,a1@(0)
addw d3,a1
swap d3
| Octets 8-15
moveq #0,d1
moveq #7,d5
c2p4_bcl815:
#if defined(__M68020__)
moveb a0@+,d0
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lea a2@(0,d0:w:4),a3
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#else
moveq #0,d0
moveb a0@+,d0
lslw #2,d0
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lea a2@(0,d0:w),a3
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#endif
lsll #1,d1
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orl a3@,d1
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dbra d5,c2p4_bcl815
movepl d1,a1@(0)
addw d3,a1
swap d3
dbra d6,c2p4_bclx
| Double line ?
tstl c2p_dblligne
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beqs c2p4_nodblligne
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movel a5,a6 | src line
movel a5,a1 | dest line
addl c2p_dstpitch,a1
movel c2p_width,d6
lsrw #3,d6
subql #1,d6
c2p4_copydbl:
movel a6@+,a1@+
dbra d6,c2p4_copydbl
addl c2p_dstpitch,a5
c2p4_nodblligne:
| Next line
movel a4,a0
addl c2p_srcpitch,a0
movel a5,a1
addl c2p_dstpitch,a1
dbra d7,c2p4_bcly
moveml sp@+,d2-d7/a2-a6
rts
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/* ------------ Conversion of a light palette in 4 bits ------------ */
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_SDL_Atari_C2pConvert4_pal:
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/* a0 is a 256-word light palette */
movel sp@(4),a0
moveml d2-d3,sp@-
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lea _SDL_Atari_table_c2p,a1
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movew #255,d3
c2p_pal_initbcl:
movew a0@+,d0
lsrw #4,d0
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andw #15,d0
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moveq #3,d1
c2p_pal_initbyte:
btst d1,d0
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sne d2
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negw d2
moveb d2,a1@(0,d1:w)
dbra d1,c2p_pal_initbyte
addql #4,a1
dbra d3,c2p_pal_initbcl
moveml sp@+,d2-d3
rts
/* ------------ Buffers ------------ */
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.bss
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.comm _SDL_Atari_C2pConvert,4
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.comm _SDL_Atari_table_c2p,1024
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.comm c2p_source,4 /* Source framebuffer */
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.comm c2p_dest,4 /* Destination framebuffer */
.comm c2p_width,4 /* Width of zone to convert */
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.comm c2p_height,4 /* Height of zone to convert */
.comm c2p_dblligne,4 /* Double the lines while converting ? */
.comm c2p_srcpitch,4 /* Source pitch */
.comm c2p_dstpitch,4 /* Destination pitch */
.comm c2p_cursrc,4 /* Current source line */
.comm c2p_curdst,4 /* Current destination line */
.comm c2p_rowlen,2 /* Line length in bytes */
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.comm c2p_row,2 /* Current line number */