From 696108c29db9a5271f45decee642a4ac72c3367d Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 25 Jun 2023 21:07:14 +0300
Subject: [PATCH] fixed vbe

---
 drv_vbe.c |    9 ++++-----
 drv_vga.c |    8 +++-----
 main.c    |   27 ++++++++++++++++++++++-----
 vidsys.c  |    9 +++++++--
 vidsys.h  |    6 +++++-
 5 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/drv_vbe.c b/drv_vbe.c
index 69c89eb..d639417 100644
--- a/drv_vbe.c
+++ b/drv_vbe.c
@@ -17,7 +17,6 @@ static int setmode(int mode);
 static int getmode(void);
 static const char *memsize_str(long sz);
 static int get_mode_info(int mode, struct vbe_mode_info *mi);
-static int setwin(int wid, int pos);
 static int conv_vbeinfo(int mode, struct vid_modeinfo *mi, struct vbe_mode_info *vbemi);
 static unsigned int calc_mask(int nbits, int pos);
 
@@ -214,7 +213,7 @@ static int get_mode_info(int mode, struct vbe_mode_info *mi)
 	return 0;
 }
 
-static int setwin(int wid, int pos)
+int vid_setwin(int wid, int pos)
 {
 	struct dpmi_regs regs = {0};
 
@@ -303,7 +302,7 @@ static int conv_vbeinfo(int mode, struct vid_modeinfo *mi, struct vbe_mode_info
 	mi->ops.unpack = unpack;
 	mi->ops.setpal = vga_setpal;
 	mi->ops.getpal = vga_getpal;
-	mi->ops.vsync = vga_vsync;
+	mi->ops.vsync = vid_vsync;
 	mi->ops.clear = clear;
 	mi->ops.blitfb = 0;
 	mi->ops.flip = flip;
@@ -369,9 +368,9 @@ static void blitfb_banked(void *fb, int pitch)
 		pptr += sz;
 		pending -= sz;
 		offs += cur_mi->win_step;
-		setwin(0, offs);
+		vid_setwin(0, offs);
 	}
-	setwin(0, 0);
+	vid_setwin(0, 0);
 }
 
 static void flip(int vsync)
diff --git a/drv_vga.c b/drv_vga.c
index 5410b60..f6b7b01 100644
--- a/drv_vga.c
+++ b/drv_vga.c
@@ -5,8 +5,6 @@
 #include "drv.h"
 #include "vga.h"
 
-void vga_vsync(void);
-
 static int init(void);
 static void cleanup(void);
 static int setmode(int mode);
@@ -32,9 +30,9 @@ static struct vid_modeinfo modes[] = {
 };
 
 static struct vid_gfxops gfxops_mode12h = {
-	0, 0, setpal4, getpal4, vga_vsync, clear4, blitfb4, 0, fill4 };
+	0, 0, setpal4, getpal4, vid_vsync, clear4, blitfb4, 0, fill4 };
 static struct vid_gfxops gfxops_mode13h = {
-	0, 0, vga_setpal, vga_getpal, vga_vsync, clear8, blitfb8, 0, fill8 };
+	0, 0, vga_setpal, vga_getpal, vid_vsync, clear8, blitfb8, 0, fill8 };
 
 void vid_register_vga(void)
 {
@@ -68,7 +66,7 @@ void vid_register_vga(void)
 	vid_drvlist[vid_numdrv++] = &drv;
 }
 
-void vga_vsync(void)
+void vid_vsync(void)
 {
 	while(inp(VGA_STAT1_PORT) & 8);
 	while((inp(VGA_STAT1_PORT) & 8) == 0);
diff --git a/main.c b/main.c
index ed2377e..476baa7 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <math.h>
+#include <limits.h>
 #include <conio.h>
 #include "vidsys.h"
 
@@ -17,8 +18,8 @@ int main(int argc, char **argv)
 {
 	int i;
 	int mode;
-	int xres = 320;
-	int yres = 200;
+	int xres = 640;
+	int yres = 480;
 	int bpp = 8;
 
 	for(i=1; i<argc; i++) {
@@ -106,8 +107,9 @@ static float fmin(float a, float b)
 void test8bpp(void)
 {
 	int i, j;
-	unsigned char *fb = vmem;
+	unsigned char *fb;
 	struct vid_color cmap[256];
+	int winsz, winleft, winpos;
 
 	for(i=0; i<256; i++) {
 		float x = (float)i / (256.0f / TWO_PI);
@@ -117,12 +119,27 @@ void test8bpp(void)
 	}
 	vid_setpal(0, 256, cmap);
 
+	if(vid_islinear()) {
+		winsz = INT_MAX;
+	} else {
+		winsz = 65536;
+		winpos = 0;
+		vid_setwin(0, 0);
+	}
+	winleft = winsz;
+	fb = vmem;
+
 	vid_vsync();
 
 	for(i=0; i<vm->height; i++) {
 		for(j=0; j<vm->width; j++) {
-			int xor = i^j;
-			*fb++ = xor;
+			if(winleft-- <= 0) {
+				winpos += vm->win_step;
+				vid_setwin(0, winpos);
+				winleft = winsz;
+				fb = vmem;
+			}
+			*fb++ = i ^ j;
 		}
 	}
 }
diff --git a/vidsys.c b/vidsys.c
index 01c8c81..d60c5f2 100644
--- a/vidsys.c
+++ b/vidsys.c
@@ -175,9 +175,14 @@ struct vid_modeinfo *vid_modeinfo(int mode)
 	return 0;
 }
 
-void vid_vsync(void)
+int vid_islinear(void)
 {
-	vga_vsync();
+	return !vid_isbanked();
+}
+
+int vid_isbanked(void)
+{
+	return cur_mode->win_size && vid_vmem < (void*)0x100000;
 }
 
 void vid_setpal(int idx, int count, const struct vid_color *col)
diff --git a/vidsys.h b/vidsys.h
index bcf7837..f40b18d 100644
--- a/vidsys.h
+++ b/vidsys.h
@@ -62,9 +62,13 @@ void *vid_setmode(int mode);
 int vid_findmode(int xsz, int ysz, int bpp);
 struct vid_modeinfo *vid_modeinfo(int mode);
 
-void vid_vsync(void);
+void vid_vsync(void);				/* defined in drv_vga.c */
+int vid_setwin(int win, int pos);	/* defined in drv_vbe.c */
 
 /* current mode functions */
+int vid_islinear(void);
+int vid_isbanked(void);
+
 void vid_setpal(int idx, int count, const struct vid_color *col);
 void vid_getpal(int idx, int count, struct vid_color *col);
 
-- 
1.7.10.4