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dosbox-staging/src/hardware/vga.cpp

312 lines
8.7 KiB
C++

/*
* Copyright (C) 2002-2003 The DOSBox Team
*
* 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 Library 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 <stdlib.h>
#include <string.h>
#include "dosbox.h"
#include "video.h"
#include "pic.h"
#include "render.h"
#include "timer.h"
#include "vga.h"
VGA_Type vga;
Bit32u CGAWriteTable[256];
Bit32u ExpandTable[256];
Bit32u Expand16Table[4][16];
Bit32u Expand16BigTable[0x10000];
Bit32u FillTable[16];
static void EndRetrace(void) {
/* start the actual display update now */
RENDER_DoUpdate();
vga.config.retrace=false;
}
static void VGA_BlankTimer() {
PIC_AddEvent(VGA_BlankTimer,vga.draw.blank);
PIC_AddEvent(EndRetrace,667);
/* Setup a timer to destroy the vertical retrace bit in a few microseconds */
vga.config.real_start=vga.config.display_start;
vga.config.retrace=true;
}
static void VGA_DrawHandler(RENDER_Part_Handler part_handler) {
Bit8u * buf,* bufsplit;
/* Draw the current frame */
if (!vga.draw.resizing) {
if (vga.config.line_compare<vga.draw.lines) {
Bitu stop=vga.config.line_compare;
if (vga.draw.double_height) stop/=2;
if (stop>=vga.draw.height){
LOG(LOG_VGAGFX,"Split at %d",stop);
goto drawnormal;
}
switch (vga.mode) {
case GFX_16:
buf=&vga.buffer[vga.config.real_start*8+vga.config.pel_panning];
bufsplit=vga.buffer;
break;
case GFX_256U:
buf=&vga.mem.linear[vga.config.real_start*4+vga.config.pel_panning/2];
bufsplit=vga.mem.linear;
break;
case GFX_256C:
buf=memory+0xa0000;
bufsplit=memory+0xa0000;
break;
default:
LOG(LOG_VGAGFX,"VGA:Unhandled split screen mode %d",vga.mode);
goto norender;
}
part_handler(buf,0,0,vga.draw.width,stop);
part_handler(bufsplit,0,stop,vga.draw.width,vga.draw.height-stop);
} else {
drawnormal:
switch (vga.mode) {
case GFX_2:
VGA_DrawGFX2_Fast(vga.buffer,vga.draw.width);
buf=vga.buffer;
break;
case GFX_4:
VGA_DrawGFX4_Fast(vga.buffer,vga.draw.width);
buf=vga.buffer;
break;
case TEXT_16:
VGA_DrawTEXT(vga.buffer,vga.draw.width);
buf=vga.buffer;
break;
case GFX_16:
buf=&vga.buffer[vga.config.real_start*8+vga.config.pel_panning];
break;
case GFX_256C:
buf=memory+0xa0000;
break;
case GFX_256U:
buf=&vga.mem.linear[vga.config.real_start*4+vga.config.pel_panning/2];
break;
}
part_handler(buf,0,0,vga.draw.width,vga.draw.height);
}
norender:;
}
}
void VGA_FindSettings(void) {
/* Sets up the correct memory handler from the vga.mode setting */
MEM_ClearPageHandlers(PAGE_COUNT(0xa0000),PAGE_COUNT(0x20000));
/* Detect the kind of video mode this is */
if (vga.config.gfxmode) {
if (vga.config.vga_enabled) {
if (vga.config.chained) {
/* 256 color chained vga */
vga.mode=GFX_256C;
//Doesn't need a memory handler
} else {
/* 256 color unchained vga */
vga.mode=GFX_256U;
MEM_SetupPageHandlers(PAGE_COUNT(0xa0000),PAGE_COUNT(0x10000),
&VGA_NormalReadHandler,&VGA_GFX_256U_WriteHandler);
}
} else if (vga.config.cga_enabled) {
/* 4 color cga */
//TODO Detect hercules modes, probably set them up in bios too
if (vga.seq.clocking_mode & 0x8) {
vga.mode=GFX_4;
// MEM_SetupPageHandlers(PAGE_COUNT(0x0b8000),PAGE_COUNT(0x10000),&VGA_GFX_4_ReadHandler,&VGA_GFX_4_WriteHandler);
} else vga.mode=GFX_2;
//TODO Maybe also use a page handler for cga mode
} else {
/* 16 color ega */
vga.mode=GFX_16;
MEM_SetupPageHandlers(PAGE_COUNT(0xa0000),PAGE_COUNT(0x10000),
&VGA_NormalReadHandler,&VGA_GFX_16_WriteHandler);
}
} else {
vga.mode=TEXT_16;
}
VGA_StartResize();
}
static void VGA_DoResize(void) {
/* Calculate the FPS for this screen */
double fps;
Bitu vtotal=2 + (vga.crtc.vertical_total | ((vga.crtc.overflow & 1) << 8) | ((vga.crtc.overflow & 0x20) << 4) );
Bitu htotal=5 + vga.crtc.horizontal_total;
Bitu vdispend = 1 + (vga.crtc.vertical_display_end | ((vga.crtc.overflow & 2)<<7) | ((vga.crtc.overflow & 0x40) << 3) );
Bitu hdispend = 1 + (vga.crtc.horizontal_display_end);
//TODO Maybe check if blanking comes before display_end
double clock=(double)vga.config.clock;
/* Check for 8 for 9 character clock mode */
if (vga.seq.clocking_mode & 1 ) clock/=8; else clock/=9;
/* Check for pixel doubling, master clock/2 */
if (vga.seq.clocking_mode & 0x8) clock/=2;
LOG(LOG_VGA,"H total %d, V Total %d",htotal,vtotal);
LOG(LOG_VGA,"H D End %d, V D End %d",hdispend,vdispend);
fps=clock/(vtotal*htotal);
vga.draw.resizing=false;
Bitu width,height,pitch,flags;
flags=0;
vga.draw.lines=height=vdispend;
width=hdispend;
vga.draw.double_height=vga.config.vline_double;
vga.draw.double_width=(vga.seq.clocking_mode & 0x8)>0;
vga.draw.font_height=vga.config.vline_height+1;
switch (vga.mode) {
case GFX_256C:
case GFX_256U:
vga.draw.double_width=true; //Hack since 256 color modes use 2 clocks for a pixel
/* Don't know might do this different sometime, will have to do for now */
if (!vga.draw.double_height) {
if (vga.config.vline_height&1) {
vga.draw.double_height=true;
vga.draw.font_height/=2;
}
}
width<<=2;
pitch=vga.config.scan_len*8;
break;
case GFX_16:
width<<=3;
pitch=vga.config.scan_len*16;
break;
case GFX_4:
width<<=3;
pitch=width;
break;
case GFX_2:
width<<=3;
pitch=width;
break;
case TEXT_16:
/* probably a 16-color text mode, got to detect mono mode somehow */
width<<=3; /* 8 bit wide text font */
if (width>640) width=640;
if (height>480) height=480;
pitch=width;
};
if (vga.draw.double_height) {
flags|=DoubleHeight;
height/=2;
}
if (vga.draw.double_width) {
flags|=DoubleWidth;
/* Double width is dividing main clock, the width should be correct already for this */
}
if (( width != vga.draw.width) || (height != vga.draw.height) || (pitch != vga.draw.pitch)) {
PIC_RemoveEvents(VGA_BlankTimer);
vga.draw.width=width;
vga.draw.height=height;
vga.draw.pitch=pitch;
LOG(LOG_VGA,"Width %d, Height %d",width,height);
LOG(LOG_VGA,"Flags %X, fps %f",flags,fps);
RENDER_SetSize(width,height,8,pitch,((float)width/(float)height),flags,&VGA_DrawHandler);
vga.draw.blank=(Bitu)(1000000/fps);
PIC_AddEvent(VGA_BlankTimer,vga.draw.blank);
}
};
void VGA_StartResize(void) {
if (!vga.draw.resizing) {
vga.draw.resizing=true;
/* Start a resize after 50 ms */
PIC_AddEvent(VGA_DoResize,50000);
}
}
void VGA_Init(Section* sec) {
vga.draw.resizing=false;
VGA_SetupMemory();
VGA_SetupMisc();
VGA_SetupDAC();
VGA_SetupGFX();
VGA_SetupSEQ();
VGA_SetupAttr();
/* Generate tables */
Bitu i,j;
for (i=0;i<256;i++) {
ExpandTable[i]=i | (i << 8)| (i <<16) | (i << 24);
#ifdef WORDS_BIGENDIAN
CGAWriteTable[i]=((i>>0)&3) | (((i>>2)&3) << 8)| (((i>>4)&3) <<16) | (((i>>6)&3) << 24);
#else
CGAWriteTable[i]=((i>>6)&3) | (((i>>4)&3) << 8)| (((i>>2)&3) <<16) | (((i>>0)&3) << 24);
#endif
}
for (i=0;i<16;i++) {
#ifdef WORDS_BIGENDIAN
FillTable[i]= ((i & 1) ? 0xff000000 : 0) |
((i & 2) ? 0x00ff0000 : 0) |
((i & 4) ? 0x0000ff00 : 0) |
((i & 8) ? 0x000000ff : 0) ;
#else
FillTable[i]= ((i & 1) ? 0x000000ff : 0) |
((i & 2) ? 0x0000ff00 : 0) |
((i & 4) ? 0x00ff0000 : 0) |
((i & 8) ? 0xff000000 : 0) ;
#endif
}
for (j=0;j<4;j++) {
for (i=0;i<16;i++) {
#ifdef WORDS_BIGENDIAN
Expand16Table[j][i] =
((i & 1) ? 1 << j : 0) |
((i & 2) ? 1 << (8 + j) : 0) |
((i & 4) ? 1 << (16 + j) : 0) |
((i & 8) ? 1 << (24 + j) : 0);
#else
Expand16Table[j][i] =
((i & 1) ? 1 << (24 + j) : 0) |
((i & 2) ? 1 << (16 + j) : 0) |
((i & 4) ? 1 << (8 + j) : 0) |
((i & 8) ? 1 << j : 0);
#endif
}
}
for (i=0;i<0x10000;i++) {
Bit32u val=0;
if (i & 0x1) val|=0x1 << 24;
if (i & 0x2) val|=0x1 << 16;
if (i & 0x4) val|=0x1 << 8;
if (i & 0x8) val|=0x1 << 0;
if (i & 0x10) val|=0x4 << 24;
if (i & 0x20) val|=0x4 << 16;
if (i & 0x40) val|=0x4 << 8;
if (i & 0x80) val|=0x4 << 0;
if (i & 0x100) val|=0x2 << 24;
if (i & 0x200) val|=0x2 << 16;
if (i & 0x400) val|=0x2 << 8;
if (i & 0x800) val|=0x2 << 0;
if (i & 0x1000) val|=0x8 << 24;
if (i & 0x2000) val|=0x8 << 16;
if (i & 0x4000) val|=0x8 << 8;
if (i & 0x8000) val|=0x8 << 0;
Expand16BigTable[i]=val;
}
}