valter/dosbox-staging
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Improve/fix aspect correction.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2954
This commit is contained in:
Peter Veenstra 2007-08-08 13:16:17 +00:00
parent 4fdda4e51e
commit c7205d0750
2 changed files with 57 additions and 8 deletions
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1
include/vga.h
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@ -130,6 +130,7 @@ typedef struct {
double hdend, htotal;
double parts;
} delay;
double aspect_ratio;
bool double_scan;
bool doublewidth,doubleheight;
Bit8u font[64*1024];

64
src/hardware/vga_draw.cpp
View file

@ -650,7 +650,7 @@ void VGA_SetupDrawing(Bitu val) {
return;
}
/* Calculate the FPS for this screen */
float fps;Bitu clock;
float fps; Bitu clock;
Bitu htotal, hdend, hbstart, hbend, hrstart, hrend;
Bitu vtotal, vdend, vbstart, vbend, vrstart, vrend;
if (machine==MCH_VGA) {
@ -710,6 +710,7 @@ void VGA_SetupDrawing(Bitu val) {
}
break;
}
/* 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 */
@ -796,8 +797,44 @@ void VGA_SetupDrawing(Bitu val) {
vga.draw.delay.vend);
*/
vga.draw.parts_total=VGA_PARTS;
double correct_ratio=(100.0/525.0);
double aspect_ratio=((double)htotal/((double)vtotal)/correct_ratio);
/*
6 Horizontal Sync Polarity. Negative if set
7 Vertical Sync Polarity. Negative if set
Bit 6-7 indicates the number of lines on the display:
1: 400, 2: 350, 3: 480
*/
//Try to determine the pixel size, aspect correct is based around square pixels
//Base pixel width around 100 clocks horizontal
//For 9 pixel text modes this should be changed, but we don't support that anyway :)
//Seems regular vga only listens to the 9 char pixel mode with character mode enabled
double pwidth = 100.0 / htotal;
//Base pixel height around vertical totals of modes that have 100 clocks horizontal
//Different sync values gives different scaling of the whole vertical range
//VGA monitor just seems to thighten or widen the whole vertical range
double pheight;
Bitu sync = vga.misc_output >> 6;
switch ( sync ) {
case 0: // This is not defined in vga specs,
// Kiet, seems to be slightly less than 350 on my monitor
//340 line mode, filled with 449 total
pheight = (480.0 / 340.0) * ( 449.0 / vtotal );
break;
case 1: //400 line mode, filled with 449 total
pheight = (480.0 / 400.0) * ( 449.0 / vtotal );
break;
case 2: //350 line mode, filled with 449 total
//This mode seems to get regular 640x400 timing and goes for a loong retrace
//Depends on the monitor to stretch the screen
pheight = (480.0 / 350.0) * ( 449.0 / vtotal );
break;
case 3: //480 line mode, filled with 525 total
pheight = (480.0 / 480.0) * ( 525.0 / vtotal );
break;
}
double aspect_ratio = pheight / pwidth;
vga.draw.delay.parts = vga.draw.delay.vdend/vga.draw.parts_total;
vga.draw.resizing=false;
@ -965,15 +1002,26 @@ void VGA_SetupDrawing(Bitu val) {
vga.changes.frame = 0;
vga.changes.writeMask = 1;
#endif
if (( width != vga.draw.width) || (height != vga.draw.height) || (vga.mode != vga.lastmode)) {
/*
Cheap hack to just make all > 640x480 modes have 4:3 aspect ratio
*/
if ( width >= 640 && height >= 480 ) {
aspect_ratio = ((float)width / (float)height) * ( 3.0 / 4.0);
}
// LOG_MSG("ht %d vt %d ratio %f", htotal, vtotal, aspect_ratio );
if (( width != vga.draw.width) || (height != vga.draw.height) ||
(aspect_ratio != vga.draw.aspect_ratio) ||
(vga.mode != vga.lastmode)) {
vga.lastmode = vga.mode;
PIC_RemoveEvents(VGA_VerticalTimer);
PIC_RemoveEvents(VGA_VerticalDisplayEnd);
PIC_RemoveEvents(VGA_DrawPart);
vga.draw.width=width;
vga.draw.height=height;
vga.draw.doublewidth=doublewidth;
vga.draw.doubleheight=doubleheight;
vga.draw.width = width;
vga.draw.height = height;
vga.draw.doublewidth = doublewidth;
vga.draw.doubleheight = doubleheight;
vga.draw.aspect_ratio = aspect_ratio;
if (doubleheight) vga.draw.lines_scaled=2;
else vga.draw.lines_scaled=1;
#if C_DEBUG