/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    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

    Lesser General Public License for more details.

    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

    Sam Lantinga

    slouken@libsdl.org

*/

/*

	Chunky to planar conversion routine

	1 byte/pixel -> 4 or 8 bit planes

	Patrice Mandin

	Xavier Joubert

	Mikael Kalms

*/

	.globl	_SDL_Atari_C2pConvert

	.globl	_SDL_Atari_C2pConvert8

	.globl	_SDL_Atari_C2pConvert4

	.globl	_SDL_Atari_C2pConvert4_pal

/* ------------	Conversion C2P, 8 bits ------------ */

	.text

_SDL_Atari_C2pConvert8:

	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,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

SDL_Atari_C2p8_rowloop:

	movel	c2p_cursrc,a0

	movel	c2p_curdst,a1

	movel	a0,a2

	addw	c2p_rowlen,a2

	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

	swap	d3

	movel	d0,a6

	movel	d2,a5

	movel	d1,a4

	movel	d3,a3

	cmpl	a0,a2

	bgt		SDL_Atari_C2p8_pix16

	movel	a3,a1@+

	movel	a4,a1@+

	movel	a5,a1@+

	movel	a6,a1@+

	/* Double the line ? */

	movel	c2p_srcpitch,d0

	movel	c2p_dstpitch,d1

	tstl	c2p_dblligne

	beqs	SDL_Atari_C2p8_nodblline

	movel	c2p_curdst,a0

	movel	a0,a1

	addl	d1,a1

	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

	addl	d1,c2p_curdst

SDL_Atari_C2p8_nodblline:

	/* Next line */

	addl	d0,c2p_cursrc

	addl	d1,c2p_curdst

	subqw	#1,c2p_row

	bne		SDL_Atari_C2p8_rowloop	

	moveml	sp@+,d2-d7/a2-a6

	rts

/* ------------	Conversion C2P, 4 bits ------------ */

_SDL_Atari_C2pConvert4:

	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

	lea	_SDL_Atari_table_c2p,a2

	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

	lea		a2@(0,d0:w:4),a3

#else

	moveq	#0,d0

	moveb	a0@+,d0

	lslw	#2,d0

	lea		a2@(0,d0:w),a3

#endif

	lsll	#1,d1

	orl		a3@,d1

	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

	lea		a2@(0,d0:w:4),a3

#else

	moveq	#0,d0

	moveb	a0@+,d0

	lslw	#2,d0

	lea		a2@(0,d0:w),a3

#endif

	lsll	#1,d1

	orl		a3@,d1

	dbra	d5,c2p4_bcl815

	movepl	d1,a1@(0)

	addw	d3,a1

	swap	d3

	dbra	d6,c2p4_bclx

	| Double line ?

	tstl	c2p_dblligne

	beqs	c2p4_nodblligne

	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

/* ------------	Conversion of a light palette in 4 bits ------------ */

_SDL_Atari_C2pConvert4_pal:

	/* a0 is a 256-word light palette */

	movel	sp@(4),a0

	moveml	d2-d3,sp@-

	lea		_SDL_Atari_table_c2p,a1

	movew	#255,d3

c2p_pal_initbcl:

	movew	a0@+,d0

	lsrw	#4,d0

	andw	#15,d0

	moveq	#3,d1

c2p_pal_initbyte:

	btst	d1,d0

	sne		d2

	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 ------------ */

	.bss

	.even

	.comm	_SDL_Atari_C2pConvert,4

	.comm	_SDL_Atari_table_c2p,1024

	.comm	c2p_source,4	/* Source framebuffer */

	.comm	c2p_dest,4		/* Destination framebuffer */

	.comm	c2p_width,4		/* Width of zone to convert */

	.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 */

	.comm	c2p_row,2		/* Current line number */