src/Unix/video_blit.cpp

/*
 *  video_blit.cpp - Video/graphics emulation, blitters
 *
 *  Basilisk II (C) 1997-2001 Christian Bauer
 *
 *  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
 */

#include "sysdeps.h"

#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>

#ifdef ENABLE_VOSF
// Format of the target visual
struct VisualFormat {
        int             depth;                                  // Screen depth
        uint32  Rmask, Gmask, Bmask;    // RGB mask values
        uint32  Rshift, Gshift, Bshift; // RGB shift values
};
static VisualFormat visualFormat;

/* -------------------------------------------------------------------------- */
/* --- Raw Copy / No conversion required                                  --- */
/* -------------------------------------------------------------------------- */

static void Blit_Copy_Raw(uint8 * dest, const uint8 * source, uint32 length)
{
        // This function is likely to be inlined and/or highly optimized
        memcpy(dest, source, length);
}

/* -------------------------------------------------------------------------- */
/* --- RGB 555                                                            --- */
/* -------------------------------------------------------------------------- */

#ifdef WORDS_BIGENDIAN
# define FB_FUNC_NAME Blit_RGB555_OBO
#else
# define FB_FUNC_NAME Blit_RGB555_NBO
#endif

#define FB_BLIT_1(dst, src) \
        (dst = (((src) >> 8) & 0xff) | (((src) & 0xff) << 8))
        
#define FB_BLIT_2(dst, src) \
        (dst = (((src) >> 8) & 0x00ff00ff) | (((src) & 0x00ff00ff) << 8))

#define FB_DEPTH 15
#include "video_blit.h"

/* -------------------------------------------------------------------------- */
/* --- BGR 555                                                            --- */
/* -------------------------------------------------------------------------- */

// TODO: BGR 555 (SGI/Irix)
// R/G/B mask values: 0x001f, 0x03e0, 0x7c00

/* -------------------------------------------------------------------------- */
/* --- RGB 565                                                            --- */
/* -------------------------------------------------------------------------- */

#ifdef WORDS_BIGENDIAN

// Native byte order

#define FB_BLIT_1(dst, src) \
        (dst = (((src) & 0x1f) | (((src) << 1) & 0xffc0)))

#define FB_BLIT_2(dst, src) \
        (dst = (((src) & 0x001f001f) | (((src) << 1) & 0xffc0ffc0)))

#define FB_DEPTH 16
#define FB_FUNC_NAME Blit_RGB565_NBO
#include "video_blit.h"

// Opposite byte order

#define FB_BLIT_1(dst, src) \
        (dst = ((((src) >> 7) & 0xff) | (((src) << 9) & 0xc000) | (((src) << 8) & 0x1f00)))

#define FB_BLIT_2(dst, src) \
        (dst = ((((src) >> 7) & 0x00ff00ff) | (((src) << 9) & 0xc000c000) | (((src) << 8) & 0x1f001f00)))

#define FB_DEPTH 16
#define FB_FUNC_NAME Blit_RGB565_OBO
#include "video_blit.h"

#else

// Native byte order

#define FB_BLIT_1(dst, src) \
        (dst = (((src) >> 8) & 0x001f) | (((src) << 9) & 0xfe00) | (((src) >> 7) & 0x01c0))
        
// gb-- Disabled because I don't see any improvement
#if 0 && defined(__i386__) && defined(X86_ASSEMBLY)

#define FB_BLIT_2(dst, src) \
        __asm__ (       "movl %0,%%ebx\n\t" \
                                "movl %0,%%ebp\n\t" \
                                "andl $0x1f001f00,%%ebx\n\t" \
                                "andl $0x007f007f,%0\n\t" \
                                "andl $0xe000e000,%%ebp\n\t" \
                                "shrl $8,%%ebx\n\t" \
                                "shrl $7,%%ebp\n\t" \
                                "shll $9,%0\n\t" \
                                "orl %%ebx,%%ebp\n\t" \
                                "orl %%ebp,%0\n\t" \
                        : "=r" (dst) : "0" (src) : "ebx", "ebp", "cc" )

#else

#define FB_BLIT_2(dst, src) \
        (dst = (((src) >> 8) & 0x001f001f) | (((src) << 9) & 0xfe00fe00) | (((src) >> 7) & 0x01c001c0))

#endif

#define FB_DEPTH 16
#define FB_FUNC_NAME Blit_RGB565_NBO
#include "video_blit.h"

// Opposite byte order (untested)

#define FB_BLIT_1(dst, src) \
        (dst = (((src) & 0x1f00) | (((src) << 1) & 0xe0fe) | (((src) >> 15) & 1)))

#define FB_BLIT_2(dst, src) \
        (dst = (((src) & 0x1f001f00) | (((src) << 1) & 0xe0fee0fe) | (((src) >> 15) & 0x10001)))

#define FB_DEPTH 16
#define FB_FUNC_NAME Blit_RGB565_OBO
#include "video_blit.h"

#endif

/* -------------------------------------------------------------------------- */
/* --- RGB 888                                                            --- */
/* -------------------------------------------------------------------------- */

#ifdef WORDS_BIGENDIAN
# define FB_FUNC_NAME Blit_RGB888_OBO
#else
# define FB_FUNC_NAME Blit_RGB888_NBO
#endif

#define FB_BLIT_2(dst, src) \
        (dst = (((src) >> 24) & 0xff) | (((src) >> 8) & 0xff00) | (((src) & 0xff00) << 8) | (((src) & 0xff) << 24))

#define FB_DEPTH 24
#include "video_blit.h"

/* -------------------------------------------------------------------------- */
/* --- BGR 888                                                            --- */
/* -------------------------------------------------------------------------- */

// Native byte order (untested)

#ifdef WORDS_BIGENDIAN

#define FB_BLIT_2(dst, src) \
        (dst = (((src) >> 16) & 0xff) | ((src) & 0xff00) | (((src) & 0xff) << 16))

#define FB_FUNC_NAME Blit_BGR888_NBO
#define FB_DEPTH 24
#include "video_blit.h"

#else

#define FB_BLIT_2(dst, src) \
        (dst = (((src) >> 16) & 0xff) | ((src) & 0xff0000) | (((src) & 0xff) << 16))

#define FB_FUNC_NAME Blit_BGR888_OBO
#define FB_DEPTH 24
#include "video_blit.h"

#endif

// Opposite byte order (untested)

#ifdef WORDS_BIGENDIAN
# define FB_FUNC_NAME Blit_BGR888_OBO
#else
# define FB_FUNC_NAME Blit_BGR888_NBO
#endif

#define FB_BLIT_2(dst, src) \
        (dst = ((src) & 0xff00ff) | (((src) & 0xff00) << 16))

#define FB_DEPTH 24
#include "video_blit.h"

/* -------------------------------------------------------------------------- */
/* --- Blitters to the host frame buffer, or XImage buffer                --- */
/* -------------------------------------------------------------------------- */

// Function used to update the hosst frame buffer (DGA), or an XImage buffer (WIN)
// --> Shall be initialized only through the Screen_blitter_init() function
typedef void (*Screen_blit_func)(uint8 * dest, const uint8 * source, uint32 length);
Screen_blit_func Screen_blit = 0;

// Structure used to match the adequate framebuffer update function
struct Screen_blit_func_info {
        int                                     depth;                  // Screen depth
        uint32                          Rmask;                  // Red mask
        uint32                          Gmask;                  // Green mask
        uint32                          Bmask;                  // Blue mask
        Screen_blit_func        handler_nbo;    // Update function (native byte order)
        Screen_blit_func        handler_obo;    // Update function (opposite byte order)
};

// Table of visual formats supported and their respective handler
static Screen_blit_func_info Screen_blitters[] = {
#ifdef WORDS_BIGENDIAN
        {  1, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw       , Blit_Copy_Raw         },      // NT
        {  8, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw       , Blit_Copy_Raw         },      // OK (NBO)
        { 15, 0x007c00, 0x0003e0, 0x00001f, Blit_Copy_Raw       , Blit_RGB555_OBO       },      // OK (OBO)
        { 16, 0x00f800, 0x0007e0, 0x00001f, Blit_RGB565_NBO     , Blit_RGB565_OBO       },      // OK (OBO)
        { 24, 0xff0000, 0x00ff00, 0x0000ff, Blit_Copy_Raw       , Blit_RGB888_OBO       },      // OK (OBO)
        { 24, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO     , Blit_BGR888_OBO       },      // NT
        { 32, 0xff0000, 0x00ff00, 0x0000ff, Blit_Copy_Raw       , Blit_RGB888_OBO       },      // OK (OBO)
        { 32, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO     , Blit_BGR888_OBO       }       // NT
#else
        {  1, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw       , Blit_Copy_Raw         },      // NT
        {  8, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw       , Blit_Copy_Raw         },      // OK (NBO)
        { 15, 0x007c00, 0x0003e0, 0x00001f, Blit_RGB555_NBO     , Blit_Copy_Raw         },      // OK (NBO)
        { 16, 0x00f800, 0x0007e0, 0x00001f, Blit_RGB565_NBO     , Blit_RGB565_OBO       },      // OK (NBO)
        { 24, 0xff0000, 0x00ff00, 0x0000ff, Blit_RGB888_NBO     , Blit_Copy_Raw         },      // OK (NBO)
        { 24, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO     , Blit_BGR888_OBO       },      // NT
        { 32, 0xff0000, 0x00ff00, 0x0000ff, Blit_RGB888_NBO     , Blit_Copy_Raw         },      // OK (NBO)
        { 32, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO     , Blit_BGR888_OBO       }       // NT
#endif
};

// Initialize the framebuffer update function
// Returns FALSE, if the function was to be reduced to a simple memcpy()
// --> In that case, VOSF is not necessary
bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order)
{
        visualFormat.depth = visual_info->depth;
        visualFormat.Rmask = visual_info->red_mask;
        visualFormat.Gmask = visual_info->green_mask;
        visualFormat.Bmask = visual_info->blue_mask;
        
        // Compute RGB shift values
        visualFormat.Rshift = 0;
        for (uint32 Rmask = visualFormat.Rmask; Rmask && ((Rmask & 1) != 1); Rmask >>= 1)
                ++visualFormat.Rshift;
        visualFormat.Gshift = 0;
        for (uint32 Gmask = visualFormat.Gmask; Gmask && ((Gmask & 1) != 1); Gmask >>= 1)
                ++visualFormat.Gshift;
        visualFormat.Bshift = 0;
        for (uint32 Bmask = visualFormat.Bmask; Bmask && ((Bmask & 1) != 1); Bmask >>= 1)
                ++visualFormat.Bshift;
        
        // Search for an adequate blit function
        bool blitter_found = false;
        const int blitters_count = sizeof(Screen_blitters)/sizeof(Screen_blitters[0]);
        for (int i = 0; !blitter_found && (i < blitters_count); i++) {
                if      (       (visualFormat.depth == Screen_blitters[i].depth)
                        &&      (visualFormat.Rmask == Screen_blitters[i].Rmask)
                        &&      (visualFormat.Gmask == Screen_blitters[i].Gmask)
                        &&      (visualFormat.Bmask == Screen_blitters[i].Bmask)
                        )
                {
                        blitter_found = true;
                        Screen_blit = native_byte_order
                                                ? Screen_blitters[i].handler_nbo
                                                : Screen_blitters[i].handler_obo
                                                ;
                }
        }
        
        // No appropriate blitter found, dump RGB mask values and abort()
        if (!blitter_found) {
                fprintf(stderr, "### No appropriate blitter found\n");
                fprintf(stderr, "\tR/G/B mask values  : 0x%06x, 0x%06x, 0x%06x (depth = %d)\n",
                        visualFormat.Rmask, visualFormat.Gmask, visualFormat.Bmask, visualFormat.depth);
                fprintf(stderr, "\tR/G/B shift values : %d/%d/%d\n",
                        visualFormat.Rshift, visualFormat.Gshift, visualFormat.Bshift);
                abort();
        }
        
        // If the blitter simply reduces to a copy, we don't need VOSF in DGA mode
        // --> In that case, we return FALSE
        return (Screen_blit != Blit_Copy_Raw);
}
#endif /* ENABLE_VOSF */
Revision:	1.1
Committed:	2001-01-28T14:05:19Z (23 years, 5 months ago) by gbeauche
Branch:	MAIN
Log Message:	Mainly changes to the VOSF code: - improved blitters selection - improved blitters performance if UNALIGNED_PROFITABLE is set - cleaned up 8 bpp blitters
#	Content
1	/*
2	* video_blit.cpp - Video/graphics emulation, blitters
3	*
4	* Basilisk II (C) 1997-2001 Christian Bauer
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19	*/
20
21	#include "sysdeps.h"
22
23	#include <stdio.h>
24	#include <stdlib.h>
25	#include <X11/Xlib.h>
26	#include <X11/Xutil.h>
27
28	#ifdef ENABLE_VOSF
29	// Format of the target visual
30	struct VisualFormat {
31	int depth; // Screen depth
32	uint32 Rmask, Gmask, Bmask; // RGB mask values
33	uint32 Rshift, Gshift, Bshift; // RGB shift values
34	};
35	static VisualFormat visualFormat;
36
37	/* -------------------------------------------------------------------------- */
38	/* --- Raw Copy / No conversion required --- */
39	/* -------------------------------------------------------------------------- */
40
41	static void Blit_Copy_Raw(uint8 * dest, const uint8 * source, uint32 length)
42	{
43	// This function is likely to be inlined and/or highly optimized
44	memcpy(dest, source, length);
45	}
46
47	/* -------------------------------------------------------------------------- */
48	/* --- RGB 555 --- */
49	/* -------------------------------------------------------------------------- */
50
51	#ifdef WORDS_BIGENDIAN
52	# define FB_FUNC_NAME Blit_RGB555_OBO
53	#else
54	# define FB_FUNC_NAME Blit_RGB555_NBO
55	#endif
56
57	#define FB_BLIT_1(dst, src) \
58	(dst = (((src) >> 8) & 0xff) \| (((src) & 0xff) << 8))
59
60	#define FB_BLIT_2(dst, src) \
61	(dst = (((src) >> 8) & 0x00ff00ff) \| (((src) & 0x00ff00ff) << 8))
62
63	#define FB_DEPTH 15
64	#include "video_blit.h"
65
66	/* -------------------------------------------------------------------------- */
67	/* --- BGR 555 --- */
68	/* -------------------------------------------------------------------------- */
69
70	// TODO: BGR 555 (SGI/Irix)
71	// R/G/B mask values: 0x001f, 0x03e0, 0x7c00
72
73	/* -------------------------------------------------------------------------- */
74	/* --- RGB 565 --- */
75	/* -------------------------------------------------------------------------- */
76
77	#ifdef WORDS_BIGENDIAN
78
79	// Native byte order
80
81	#define FB_BLIT_1(dst, src) \
82	(dst = (((src) & 0x1f) \| (((src) << 1) & 0xffc0)))
83
84	#define FB_BLIT_2(dst, src) \
85	(dst = (((src) & 0x001f001f) \| (((src) << 1) & 0xffc0ffc0)))
86
87	#define FB_DEPTH 16
88	#define FB_FUNC_NAME Blit_RGB565_NBO
89	#include "video_blit.h"
90
91	// Opposite byte order
92
93	#define FB_BLIT_1(dst, src) \
94	(dst = ((((src) >> 7) & 0xff) \| (((src) << 9) & 0xc000) \| (((src) << 8) & 0x1f00)))
95
96	#define FB_BLIT_2(dst, src) \
97	(dst = ((((src) >> 7) & 0x00ff00ff) \| (((src) << 9) & 0xc000c000) \| (((src) << 8) & 0x1f001f00)))
98
99	#define FB_DEPTH 16
100	#define FB_FUNC_NAME Blit_RGB565_OBO
101	#include "video_blit.h"
102
103	#else
104
105	// Native byte order
106
107	#define FB_BLIT_1(dst, src) \
108	(dst = (((src) >> 8) & 0x001f) \| (((src) << 9) & 0xfe00) \| (((src) >> 7) & 0x01c0))
109
110	// gb-- Disabled because I don't see any improvement
111	#if 0 && defined(__i386__) && defined(X86_ASSEMBLY)
112
113	#define FB_BLIT_2(dst, src) \
114	__asm__ ( "movl %0,%%ebx\n\t" \
115	"movl %0,%%ebp\n\t" \
116	"andl $0x1f001f00,%%ebx\n\t" \
117	"andl $0x007f007f,%0\n\t" \
118	"andl $0xe000e000,%%ebp\n\t" \
119	"shrl $8,%%ebx\n\t" \
120	"shrl $7,%%ebp\n\t" \
121	"shll $9,%0\n\t" \
122	"orl %%ebx,%%ebp\n\t" \
123	"orl %%ebp,%0\n\t" \
124	: "=r" (dst) : "0" (src) : "ebx", "ebp", "cc" )
125
126	#else
127
128	#define FB_BLIT_2(dst, src) \
129	(dst = (((src) >> 8) & 0x001f001f) \| (((src) << 9) & 0xfe00fe00) \| (((src) >> 7) & 0x01c001c0))
130
131	#endif
132
133	#define FB_DEPTH 16
134	#define FB_FUNC_NAME Blit_RGB565_NBO
135	#include "video_blit.h"
136
137	// Opposite byte order (untested)
138
139	#define FB_BLIT_1(dst, src) \
140	(dst = (((src) & 0x1f00) \| (((src) << 1) & 0xe0fe) \| (((src) >> 15) & 1)))
141
142	#define FB_BLIT_2(dst, src) \
143	(dst = (((src) & 0x1f001f00) \| (((src) << 1) & 0xe0fee0fe) \| (((src) >> 15) & 0x10001)))
144
145	#define FB_DEPTH 16
146	#define FB_FUNC_NAME Blit_RGB565_OBO
147	#include "video_blit.h"
148
149	#endif
150
151	/* -------------------------------------------------------------------------- */
152	/* --- RGB 888 --- */
153	/* -------------------------------------------------------------------------- */
154
155	#ifdef WORDS_BIGENDIAN
156	# define FB_FUNC_NAME Blit_RGB888_OBO
157	#else
158	# define FB_FUNC_NAME Blit_RGB888_NBO
159	#endif
160
161	#define FB_BLIT_2(dst, src) \
162	(dst = (((src) >> 24) & 0xff) \| (((src) >> 8) & 0xff00) \| (((src) & 0xff00) << 8) \| (((src) & 0xff) << 24))
163
164	#define FB_DEPTH 24
165	#include "video_blit.h"
166
167	/* -------------------------------------------------------------------------- */
168	/* --- BGR 888 --- */
169	/* -------------------------------------------------------------------------- */
170
171	// Native byte order (untested)
172
173	#ifdef WORDS_BIGENDIAN
174
175	#define FB_BLIT_2(dst, src) \
176	(dst = (((src) >> 16) & 0xff) \| ((src) & 0xff00) \| (((src) & 0xff) << 16))
177
178	#define FB_FUNC_NAME Blit_BGR888_NBO
179	#define FB_DEPTH 24
180	#include "video_blit.h"
181
182	#else
183
184	#define FB_BLIT_2(dst, src) \
185	(dst = (((src) >> 16) & 0xff) \| ((src) & 0xff0000) \| (((src) & 0xff) << 16))
186
187	#define FB_FUNC_NAME Blit_BGR888_OBO
188	#define FB_DEPTH 24
189	#include "video_blit.h"
190
191	#endif
192
193	// Opposite byte order (untested)
194
195	#ifdef WORDS_BIGENDIAN
196	# define FB_FUNC_NAME Blit_BGR888_OBO
197	#else
198	# define FB_FUNC_NAME Blit_BGR888_NBO
199	#endif
200
201	#define FB_BLIT_2(dst, src) \
202	(dst = ((src) & 0xff00ff) \| (((src) & 0xff00) << 16))
203
204	#define FB_DEPTH 24
205	#include "video_blit.h"
206
207	/* -------------------------------------------------------------------------- */
208	/* --- Blitters to the host frame buffer, or XImage buffer --- */
209	/* -------------------------------------------------------------------------- */
210
211	// Function used to update the hosst frame buffer (DGA), or an XImage buffer (WIN)
212	// --> Shall be initialized only through the Screen_blitter_init() function
213	typedef void (Screen_blit_func)(uint8 dest, const uint8 * source, uint32 length);
214	Screen_blit_func Screen_blit = 0;
215
216	// Structure used to match the adequate framebuffer update function
217	struct Screen_blit_func_info {
218	int depth; // Screen depth
219	uint32 Rmask; // Red mask
220	uint32 Gmask; // Green mask
221	uint32 Bmask; // Blue mask
222	Screen_blit_func handler_nbo; // Update function (native byte order)
223	Screen_blit_func handler_obo; // Update function (opposite byte order)
224	};
225
226	// Table of visual formats supported and their respective handler
227	static Screen_blit_func_info Screen_blitters[] = {
228	#ifdef WORDS_BIGENDIAN
229	{ 1, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw , Blit_Copy_Raw }, // NT
230	{ 8, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw , Blit_Copy_Raw }, // OK (NBO)
231	{ 15, 0x007c00, 0x0003e0, 0x00001f, Blit_Copy_Raw , Blit_RGB555_OBO }, // OK (OBO)
232	{ 16, 0x00f800, 0x0007e0, 0x00001f, Blit_RGB565_NBO , Blit_RGB565_OBO }, // OK (OBO)
233	{ 24, 0xff0000, 0x00ff00, 0x0000ff, Blit_Copy_Raw , Blit_RGB888_OBO }, // OK (OBO)
234	{ 24, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO , Blit_BGR888_OBO }, // NT
235	{ 32, 0xff0000, 0x00ff00, 0x0000ff, Blit_Copy_Raw , Blit_RGB888_OBO }, // OK (OBO)
236	{ 32, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO , Blit_BGR888_OBO } // NT
237	#else
238	{ 1, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw , Blit_Copy_Raw }, // NT
239	{ 8, 0x000000, 0x000000, 0x000000, Blit_Copy_Raw , Blit_Copy_Raw }, // OK (NBO)
240	{ 15, 0x007c00, 0x0003e0, 0x00001f, Blit_RGB555_NBO , Blit_Copy_Raw }, // OK (NBO)
241	{ 16, 0x00f800, 0x0007e0, 0x00001f, Blit_RGB565_NBO , Blit_RGB565_OBO }, // OK (NBO)
242	{ 24, 0xff0000, 0x00ff00, 0x0000ff, Blit_RGB888_NBO , Blit_Copy_Raw }, // OK (NBO)
243	{ 24, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO , Blit_BGR888_OBO }, // NT
244	{ 32, 0xff0000, 0x00ff00, 0x0000ff, Blit_RGB888_NBO , Blit_Copy_Raw }, // OK (NBO)
245	{ 32, 0x0000ff, 0x00ff00, 0xff0000, Blit_BGR888_NBO , Blit_BGR888_OBO } // NT
246	#endif
247	};
248
249	// Initialize the framebuffer update function
250	// Returns FALSE, if the function was to be reduced to a simple memcpy()
251	// --> In that case, VOSF is not necessary
252	bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order)
253	{
254	visualFormat.depth = visual_info->depth;
255	visualFormat.Rmask = visual_info->red_mask;
256	visualFormat.Gmask = visual_info->green_mask;
257	visualFormat.Bmask = visual_info->blue_mask;
258
259	// Compute RGB shift values
260	visualFormat.Rshift = 0;
261	for (uint32 Rmask = visualFormat.Rmask; Rmask && ((Rmask & 1) != 1); Rmask >>= 1)
262	++visualFormat.Rshift;
263	visualFormat.Gshift = 0;
264	for (uint32 Gmask = visualFormat.Gmask; Gmask && ((Gmask & 1) != 1); Gmask >>= 1)
265	++visualFormat.Gshift;
266	visualFormat.Bshift = 0;
267	for (uint32 Bmask = visualFormat.Bmask; Bmask && ((Bmask & 1) != 1); Bmask >>= 1)
268	++visualFormat.Bshift;
269
270	// Search for an adequate blit function
271	bool blitter_found = false;
272	const int blitters_count = sizeof(Screen_blitters)/sizeof(Screen_blitters[0]);
273	for (int i = 0; !blitter_found && (i < blitters_count); i++) {
274	if ( (visualFormat.depth == Screen_blitters[i].depth)
275	&& (visualFormat.Rmask == Screen_blitters[i].Rmask)
276	&& (visualFormat.Gmask == Screen_blitters[i].Gmask)
277	&& (visualFormat.Bmask == Screen_blitters[i].Bmask)
278	)
279	{
280	blitter_found = true;
281	Screen_blit = native_byte_order
282	? Screen_blitters[i].handler_nbo
283	: Screen_blitters[i].handler_obo
284	;
285	}
286	}
287
288	// No appropriate blitter found, dump RGB mask values and abort()
289	if (!blitter_found) {
290	fprintf(stderr, "### No appropriate blitter found\n");
291	fprintf(stderr, "\tR/G/B mask values : 0x%06x, 0x%06x, 0x%06x (depth = %d)\n",
292	visualFormat.Rmask, visualFormat.Gmask, visualFormat.Bmask, visualFormat.depth);
293	fprintf(stderr, "\tR/G/B shift values : %d/%d/%d\n",
294	visualFormat.Rshift, visualFormat.Gshift, visualFormat.Bshift);
295	abort();
296	}
297
298	// If the blitter simply reduces to a copy, we don't need VOSF in DGA mode
299	// --> In that case, we return FALSE
300	return (Screen_blit != Blit_Copy_Raw);
301	}
302	#endif /* ENABLE_VOSF */