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/* |
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* video_vosf.h - Video/graphics emulation, video on SEGV signals support |
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* |
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* Basilisk II (C) 1997-2001 Christian Bauer |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#ifndef VIDEO_VOSF_H |
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#define VIDEO_VOSF_H |
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|
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// Note: this file is #include'd in video_x.cpp |
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#ifdef ENABLE_VOSF |
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|
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/* |
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* Page-aligned memory allocation |
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*/ |
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|
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// Align on page boundaries |
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static uintptr align_on_page_boundary(uintptr size) |
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{ |
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const uint32 page_size = getpagesize(); |
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const uint32 page_mask = page_size - 1; |
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return (size + page_mask) & ~page_mask; |
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} |
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|
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// Allocate memory on page boundary |
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static void * allocate_framebuffer(uint32 size, uint8 * hint = 0) |
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{ |
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// Remind that the system can allocate at 0x00000000... |
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return mmap((caddr_t)hint, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, zero_fd, 0); |
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} |
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|
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|
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/* |
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* Screen fault handler |
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*/ |
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|
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const uintptr INVALID_PC = (uintptr)-1; |
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|
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static inline void do_handle_screen_fault(uintptr addr, uintptr pc = INVALID_PC) |
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{ |
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/* Someone attempted to write to the frame buffer. Make it writeable |
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* now so that the data could actually be written. It will be made |
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* read-only back in one of the screen update_*() functions. |
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*/ |
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if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) { |
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const int page = (addr - mainBuffer.memStart) >> mainBuffer.pageBits; |
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caddr_t page_ad = (caddr_t)(addr & ~(mainBuffer.pageSize - 1)); |
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LOCK_VOSF; |
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PFLAG_SET(page); |
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mprotect(page_ad, mainBuffer.pageSize, PROT_READ | PROT_WRITE); |
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mainBuffer.dirty = true; |
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UNLOCK_VOSF; |
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return; |
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} |
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|
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/* Otherwise, we don't know how to handle the fault, let it crash */ |
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fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr); |
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if (pc != INVALID_PC) |
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fprintf(stderr, " [IP=0x%08X]", pc); |
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fprintf(stderr, "\n"); |
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|
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signal(SIGSEGV, SIG_DFL); |
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} |
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|
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#if defined(HAVE_SIGINFO_T) |
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|
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static void Screen_fault_handler(int, siginfo_t * sip, void *) |
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{ |
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D(bug("Screen_fault_handler: ADDR=0x%08X\n", sip->si_addr)); |
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do_handle_screen_fault((uintptr)sip->si_addr); |
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} |
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|
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#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE) |
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|
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# if defined(__i386__) && defined(__linux__) |
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static void Screen_fault_handler(int, struct sigcontext scs) |
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{ |
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D(bug("Screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", scs.cr2, scs.eip)); |
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do_handle_screen_fault((uintptr)scs.cr2, (uintptr)scs.eip); |
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} |
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|
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# elif defined(__m68k__) && defined(__NetBSD__) |
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|
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# include <m68k/frame.h> |
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static void Screen_fault_handler(int, int code, struct sigcontext *scp) |
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{ |
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D(bug("Screen_fault_handler: ADDR=0x%08X\n", code)); |
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struct sigstate { |
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int ss_flags; |
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struct frame ss_frame; |
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}; |
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struct sigstate *state = (struct sigstate *)scp->sc_ap; |
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uintptr fault_addr; |
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switch (state->ss_frame.f_format) { |
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case 7: // 68040 access error |
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// "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown |
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fault_addr = state->ss_frame.f_fmt7.f_fa; |
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break; |
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default: |
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fault_addr = (uintptr)code; |
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break; |
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} |
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do_handle_screen_fault(fault_addr); |
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} |
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|
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# elif defined(__powerpc__) && defined(__linux__) |
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|
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static void Screen_fault_handler(int, struct sigcontext_struct *scs) |
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{ |
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D(bug("Screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", scs->regs->dar, scs->regs->nip)); |
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do_handle_screen_fault((uintptr)scs->regs->dar, (uintptr)scs->regs->nip); |
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} |
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|
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# else |
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# error "No suitable subterfuge for Video on SEGV signals" |
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# endif |
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#else |
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# error "Can't do Video on SEGV signals" |
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#endif |
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|
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|
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/* |
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* Screen fault handler initialization |
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*/ |
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|
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#if defined(HAVE_SIGINFO_T) |
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static bool Screen_fault_handler_init() |
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{ |
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// Setup SIGSEGV handler to process writes to frame buffer |
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sigemptyset(&vosf_sa.sa_mask); |
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vosf_sa.sa_sigaction = Screen_fault_handler; |
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vosf_sa.sa_flags = SA_SIGINFO; |
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return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0); |
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} |
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#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE) |
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static bool Screen_fault_handler_init() |
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{ |
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// Setup SIGSEGV handler to process writes to frame buffer |
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sigemptyset(&vosf_sa.sa_mask); |
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vosf_sa.sa_handler = (void (*)(int)) Screen_fault_handler; |
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#if !EMULATED_68K && defined(__NetBSD__) |
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sigaddset(&vosf_sa.sa_mask, SIGALRM); |
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vosf_sa.sa_flags = SA_ONSTACK; |
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#else |
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vosf_sa.sa_flags = 0; |
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#endif |
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return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0); |
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} |
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#endif |
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|
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|
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/* |
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* Update display for Windowed mode and VOSF |
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*/ |
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|
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// From video_blit.cpp |
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extern void (*Screen_blit)(uint8 * dest, const uint8 * source, uint32 length); |
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extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order); |
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|
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/* How can we deal with array overrun conditions ? |
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|
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The state of the framebuffer pages that have been touched are maintained |
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in the dirtyPages[] table. That table is (pageCount + 2) bytes long. |
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|
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Terminology |
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|
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"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1]. |
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"CLEAR Page Guard" refers to the page following the Last Page but is always |
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in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR |
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Page Guard but is always in the SET state. |
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|
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Rough process |
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|
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The update routines must determine which pages have to be blitted to the |
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screen. This job consists in finding the first_page that was touched. |
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i.e. find the next page that is SET. Then, finding how many pages were |
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touched starting from first_page. i.e. find the next page that is CLEAR. |
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|
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There are two cases to check: |
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|
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- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard |
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but it is beyond the valid pageCount value. Therefore, we exit from the |
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update routine. |
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|
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- Last Page is SET: first_page equals (pageCount - 1) and |
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find_next_page_clear() will reach the CLEAR Page Guard. We blit the last |
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page to the screen. On the next iteration, page equals pageCount and |
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find_next_page_set() will reach the SET Page Guard. We still safely exit |
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from the update routine because the SET Page Guard position is greater |
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than pageCount. |
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*/ |
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|
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static inline void update_display_window_vosf(void) |
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{ |
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int page = 0; |
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for (;;) { |
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const int first_page = find_next_page_set(page); |
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if (first_page >= mainBuffer.pageCount) |
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break; |
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|
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page = find_next_page_clear(first_page); |
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PFLAG_CLEAR_RANGE(first_page, page); |
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|
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// Make the dirty pages read-only again |
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const int32 offset = first_page << mainBuffer.pageBits; |
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const uint32 length = (page - first_page) << mainBuffer.pageBits; |
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mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_READ); |
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|
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// There is at least one line to update |
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const int y1 = mainBuffer.pageInfo[first_page].top; |
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const int y2 = mainBuffer.pageInfo[page - 1].bottom; |
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const int height = y2 - y1 + 1; |
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|
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const int bytes_per_row = VideoMonitor.bytes_per_row; |
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const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x; |
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int i = y1 * bytes_per_row, j; |
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|
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if (depth == 1) { |
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|
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// Update the_host_buffer and copy of the_buffer |
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for (j = y1; j <= y2; j++) { |
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Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.x >> 3); |
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i += bytes_per_row; |
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} |
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|
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} else { |
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|
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// Update the_host_buffer and copy of the_buffer |
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for (j = y1; j <= y2; j++) { |
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Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.x); |
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i += bytes_per_row; |
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} |
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} |
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|
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if (have_shm) |
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XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height, 0); |
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else |
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XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.x, height); |
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} |
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|
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mainBuffer.dirty = false; |
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} |
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|
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|
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/* |
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* Update display for DGA mode and VOSF |
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* (only in Direct Addressing mode) |
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*/ |
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|
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#if REAL_ADDRESSING || DIRECT_ADDRESSING |
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static inline void update_display_dga_vosf(void) |
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{ |
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int page = 0; |
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for (;;) { |
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const int first_page = find_next_page_set(page); |
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if (first_page >= mainBuffer.pageCount) |
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break; |
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|
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page = find_next_page_clear(first_page); |
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PFLAG_CLEAR_RANGE(first_page, page); |
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|
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// Make the dirty pages read-only again |
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const int32 offset = first_page << mainBuffer.pageBits; |
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const uint32 length = (page - first_page) << mainBuffer.pageBits; |
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mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_READ); |
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|
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// I am sure that y2 >= y1 and depth != 1 |
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const int y1 = mainBuffer.pageInfo[first_page].top; |
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const int y2 = mainBuffer.pageInfo[page - 1].bottom; |
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|
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const int bytes_per_row = VideoMonitor.bytes_per_row; |
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const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x; |
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int i, j; |
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|
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// Check for first column from left and first column |
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// from right that have changed |
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int x1 = VideoMonitor.x * bytes_per_pixel - 1; |
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for (j = y1; j <= y2; j++) { |
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uint8 * const p1 = &the_buffer[j * bytes_per_row]; |
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uint8 * const p2 = &the_buffer_copy[j * bytes_per_row]; |
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for (i = 0; i < x1; i++) { |
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if (p1[i] != p2[i]) { |
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x1 = i; |
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break; |
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} |
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} |
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} |
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x1 /= bytes_per_pixel; |
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|
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int x2 = x1 * bytes_per_pixel; |
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for (j = y2; j >= y1; j--) { |
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uint8 * const p1 = &the_buffer[j * bytes_per_row]; |
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uint8 * const p2 = &the_buffer_copy[j * bytes_per_row]; |
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for (i = VideoMonitor.x * bytes_per_pixel - 1; i > x2; i--) { |
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if (p1[i] != p2[i]) { |
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x2 = i; |
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break; |
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} |
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} |
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} |
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x2 /= bytes_per_pixel; |
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|
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// Update the_host_buffer and copy of the_buffer |
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// There should be at least one pixel to copy |
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const int width = x2 - x1 + 1; |
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i = y1 * bytes_per_row + x1 * bytes_per_pixel; |
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for (j = y1; j <= y2; j++) { |
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Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width); |
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memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width); |
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i += bytes_per_row; |
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} |
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} |
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mainBuffer.dirty = false; |
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} |
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#endif |
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|
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#endif /* ENABLE_VOSF */ |
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|
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#endif /* VIDEO_VOSF_H */ |
