From 895995c073680a044a0e2aa0f9fdbe935259e856 Mon Sep 17 00:00:00 2001
From: Sjoerd van der Berg <harekiet@users.sourceforge.net>
Date: Sat, 8 Nov 2003 10:11:25 +0000
Subject: [PATCH] Added some kind of aspect correction calcuation, still not
 perfect

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1414
---
 src/hardware/vga_draw.cpp | 60 +++++++++++++++++++--------------------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/src/hardware/vga_draw.cpp b/src/hardware/vga_draw.cpp
index 1365795e..a8de2f15 100644
--- a/src/hardware/vga_draw.cpp
+++ b/src/hardware/vga_draw.cpp
@@ -30,11 +30,8 @@
 static void VGA_HERC_Draw(Bit8u * bitdata,Bitu pitch) {
 	Bit8u * reader=&vga.mem.linear[(vga.herc.mode_control & 0x80) ? 8*1024 : 0];
 	for (Bitu y=0;y<vga.draw.height;y++) {
-//		Bit8u * tempread=reader+((y & 3) * 8 * 1024);
 		Bit8u * tempread=reader+((y & 3) * 8 * 1024);
-//		Bit8u * tempread=reader;
 		Bit8u * draw=bitdata;
-		//TODO Look up table like in 4color mode
 		for (Bitu x=vga.draw.width>>3;x>0;x--) {
 			Bit8u val=*(tempread++);
 			*(Bit32u *)(draw+0)=CGA_2_Table[val >> 4];
@@ -259,8 +256,7 @@ void VGA_DrawHandler(RENDER_Part_Handler part_handler) {
 	/* 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;
+			Bitu stop=vga.config.line_compare/vga.draw.scaleh;
 			if (stop>=vga.draw.height){
 				LOG(LOG_VGAGFX,LOG_NORMAL)("Split at %d",stop);
 				goto drawnormal;
@@ -348,9 +344,13 @@ norender:;
 void VGA_SetupDrawing(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 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 vdispend = 1 + (vga.crtc.vertical_display_end | 
+		((vga.crtc.overflow & 2)<<7) | ((vga.crtc.overflow & 0x40) << 3) | 
+		((vga.s3.ex_ver_overflow & 0x2) << 9));
 	Bitu hdispend = 1 + (vga.crtc.horizontal_display_end);
 	
 	Bitu hbstart = vga.crtc.start_horizontal_blanking;
@@ -365,19 +365,25 @@ void VGA_SetupDrawing(void) {
 	/* 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;
+	if (vga.seq.clocking_mode & 0x8) {
+		clock/=2;
+		htotal*=2;
+	}
 	/* Check for dual transfer whatever thing,master clock/2 */
 	if (vga.s3.pll.cmd & 0x10) clock/=2;
 
-
+	
 	LOG(LOG_VGA,LOG_NORMAL)("H total %d, V Total %d",htotal,vtotal);
 	LOG(LOG_VGA,LOG_NORMAL)("H D End %d, V D End %d",hdispend,vdispend);
 	fps=clock/(vtotal*htotal);
-
+	double correct_ratio=(100.0/525.0);
+	double aspect_ratio=((double)htotal/((double)vtotal)/correct_ratio);
+	
 	vga.draw.resizing=false;
-	Bitu width,height,pitch,flags;
+	Bitu width,height,pitch;
+	Bitu scalew=1;
+	Bitu scaleh=1;
 
-	flags=0;
 	vga.draw.lines=height=vdispend;
 	width=hdispend;
 	vga.draw.double_height=vga.config.vline_double;
@@ -387,29 +393,19 @@ void VGA_SetupDrawing(void) {
 	case M_VGA:
 		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;
-			}
-		}
+		scaleh*=vga.draw.font_height;
 		width<<=2;
 		pitch=vga.config.scan_len*8;
 		break;
 	case M_LIN8:
 		width<<=3;
-		if (vga.draw.double_width) width>>=1;
-		if (!vga.draw.double_height) {
-			if (vga.config.vline_height&1) {
-				vga.draw.double_height=true;
-				vga.draw.font_height/=2;
-			}
-		}
+		scaleh*=vga.draw.font_height;
 		pitch=vga.config.scan_len*8;
 		break;
 	case M_EGA16:
 		width<<=3;
 		pitch=vga.config.scan_len*16;
+		scaleh*=vga.draw.font_height;
 		break;
 	case M_CGA4:
 	case M_CGA16:							//Let is use 320x200 res and double pixels myself
@@ -435,6 +431,7 @@ void VGA_SetupDrawing(void) {
 		break;
 	case M_TEXT2:
 	case M_TEXT16:
+		aspect_ratio=1.0;
 		vga.draw.font_height=vga.config.vline_height+1;
 		if (vga.draw.font_height<4 && (machine<MCH_VGA || machine==MCH_AUTO)) {
 			vga.draw.font_height=4;
@@ -451,22 +448,23 @@ void VGA_SetupDrawing(void) {
 		LOG(LOG_VGA,LOG_ERROR)("Unhandled VGA type %d while checking for resolution");
 	};
 	if (vga.draw.double_height) {
-		flags|=DoubleHeight;
-		height/=2;
+		scaleh*=2;
 	}
+	height/=scaleh;
 	if (vga.draw.double_width) {
-		flags|=DoubleWidth;
 		/* Double width is dividing main clock, the width should be correct already for this */
+		scalew*=2;
 	}
 	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;
+		vga.draw.scaleh=scaleh;
 
-		LOG(LOG_VGA,LOG_NORMAL)("Width %d, Height %d, Pitch %d",width,height,pitch);
-		LOG(LOG_VGA,LOG_NORMAL)("Flags %X, fps %f",flags,fps);
-		RENDER_SetSize(width,height,8,pitch,((float)width/(float)height),flags,&VGA_DrawHandler);
+		LOG(LOG_VGA,LOG_NORMAL)("Width %d, Height %d, Pitch %d fps %f",width,height,pitch,fps);
+		LOG(LOG_VGA,LOG_NORMAL)("Scalew %d, Scaleh %d aspect %f",scalew,scaleh,aspect_ratio);
+		RENDER_SetSize(width,height,8,pitch,aspect_ratio,scalew,scaleh,&VGA_DrawHandler);
 		vga.draw.blank=(Bitu)(1000000/fps);
 		PIC_AddEvent(VGA_BlankTimer,vga.draw.blank);
 	}