From 6018e36555e1a02bc85e6b4212a0e70dec79a264 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Mon, 26 Jun 2023 19:54:53 +0300
Subject: [PATCH] correct window size in banked vbe, and added doublebuffered
 test

---
 drv_vbe.c |    6 ++-
 main.c    |  140 +++++++++++++++++++++++++++++++++++++++++++++++++++----------
 vidsys.c  |    7 +++-
 vidsys.h  |    2 +-
 4 files changed, 127 insertions(+), 28 deletions(-)

diff --git a/drv_vbe.c b/drv_vbe.c
index d639417..e09ca4d 100644
--- a/drv_vbe.c
+++ b/drv_vbe.c
@@ -356,14 +356,16 @@ static void blitfb_lfb(void *fb, int pitch)
 
 static void blitfb_banked(void *fb, int pitch)
 {
-	int sz, offs, pending;
+	int sz, offs, pending, winsz;
 	unsigned char *pptr = fb;
 
+	winsz = cur_mi->win_size << 10;
+
 	/* assume initial window offset at 0 */
 	offs = 0;
 	pending = cur_pgsize;
 	while(pending > 0) {
-		sz = pending > 65536 ? 65536 : pending;
+		sz = pending > winsz ? winsz : pending;
 		memcpy((void*)0xa0000, pptr, sz);
 		pptr += sz;
 		pending -= sz;
diff --git a/main.c b/main.c
index 476baa7..a087561 100644
--- a/main.c
+++ b/main.c
@@ -5,14 +5,17 @@
 #include "vidsys.h"
 
 void test8bpp(void);
+void testrgb(void);
 
 struct vid_modeinfo *vm;
-void *vmem;
+void *vmem, *framebuf;
+int doublebuf;
 
 static const char *usage_fmt = "Usage %s: [options]\n"
 	"Options:      \n"
 	" -s <XxY>: video resolution\n"
-	" -b <bpp>: color depth\n";
+	" -b <bpp>: color depth\n"
+	" -d: double buffer\n";
 
 int main(int argc, char **argv)
 {
@@ -41,6 +44,11 @@ invalopt:		fprintf(stderr, "invalid option: %s\n", argv[i]);
 					fprintf(stderr, "invalid color depth: %s\n", argv[i]);
 					return 1;
 				}
+				break;
+
+			case 'd':
+				doublebuf = 1;
+				break;
 
 			case 'h':
 				printf(usage_fmt, argv[0]);
@@ -67,19 +75,22 @@ invalopt:		fprintf(stderr, "invalid option: %s\n", argv[i]);
 		fprintf(stderr, "failed to find video mode: %dx%d %dbpp\n", xres, yres, bpp);
 		return 1;
 	}
+	vm = vid_modeinfo(mode);
+
+	if(!(framebuf = malloc(vm->pitch * vm->width))) {
+		fprintf(stderr, "failed to allocate main memory framebuffer\n");
+		return 1;
+	}
+
 	if(!(vmem = vid_setmode(mode))) {
 		fprintf(stderr, "failed to set video mode %04x\n", mode);
 		return 1;
 	}
-	vm = vid_modeinfo(mode);
 
-	switch(vm->bpp) {
-	case 8:
+	if(vm->bpp == 8) {
 		test8bpp();
-		break;
-
-	default:
-		break;
+	} else {
+		testrgb();
 	}
 
 	for(;;) {
@@ -119,27 +130,110 @@ void test8bpp(void)
 	}
 	vid_setpal(0, 256, cmap);
 
-	if(vid_islinear()) {
-		winsz = INT_MAX;
+	if(doublebuf) {
+		fb = framebuf;
+		for(i=0; i<vm->height; i++) {
+			for(j=0; j<vm->width; j++) {
+				*fb++ = i ^ j;
+			}
+		}
+		vid_blitfb(framebuf, 0);
 	} else {
-		winsz = 65536;
-		winpos = 0;
-		vid_setwin(0, 0);
+		if(vid_islinear()) {
+			winsz = INT_MAX;
+		} else {
+			winsz = vm->win_size << 10;
+			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++) {
+				if(winleft-- <= 0) {
+					winpos += vm->win_step;
+					vid_setwin(0, winpos);
+					winleft = winsz;
+					fb = vmem;
+				}
+				*fb++ = i ^ j;
+			}
+		}
 	}
-	winleft = winsz;
-	fb = vmem;
+}
 
-	vid_vsync();
+void testrgb(void)
+{
+	int i, j, r, g, b;
+	unsigned char *fb24;
+	uint16_t *fb16;
+	uint32_t *fb32;
+	uint32_t pcol;
+	int winsz, winleft, winpos;
+
+	if(!doublebuf) {
+		if(vid_islinear()) {
+			winsz = INT_MAX;
+		} else {
+			winsz = vm->win_size << 10;
+			winpos = 0;
+			vid_setwin(0, 0);
+		}
+		winleft = winsz;
+		fb24 = vmem;
+		fb32 = vmem;
+		fb16 = vmem;
+
+		vid_vsync();
+	} else {
+		fb24 = framebuf;
+		fb32 = framebuf;
+		fb16 = framebuf;
+	}
 
 	for(i=0; i<vm->height; i++) {
 		for(j=0; j<vm->width; j++) {
-			if(winleft-- <= 0) {
-				winpos += vm->win_step;
-				vid_setwin(0, winpos);
-				winleft = winsz;
-				fb = vmem;
+			if(!doublebuf) {
+				if(winleft <= 0) {
+					winpos += vm->win_step;
+					vid_setwin(0, winpos);
+					winleft = winsz;
+					fb24 = vmem;
+					fb16 = vmem;
+					fb32 = vmem;
+				}
+				winleft -= (vm->bpp + 7) >> 3;
+			}
+			r = (i ^ j) >> 1;
+			g = i ^ j;
+			b = (i ^ j) << 1;
+			vm->ops.pack(&pcol, r, g, b);
+
+			switch(vm->bpp) {
+			case 15:
+			case 16:
+				*fb16++ = pcol;
+				break;
+
+			case 24:
+				fb24[0] = r;
+				fb24[1] = g;
+				fb24[2] = b;
+				fb24 += 3;
+				break;
+
+			case 32:
+				*fb32++ = pcol;
+				break;
 			}
-			*fb++ = i ^ j;
 		}
 	}
+
+	if(doublebuf) {
+		vid_vsync();
+		vid_blitfb(framebuf, 0);
+	}
 }
diff --git a/vidsys.c b/vidsys.c
index 427dbb5..3a88f9c 100644
--- a/vidsys.c
+++ b/vidsys.c
@@ -195,7 +195,10 @@ void vid_getpal(int idx, int count, struct vid_color *col)
 	cur_mode->ops.getpal(idx, count, col);
 }
 
-void vid_blitfb(void *fb, int vsync)
+void vid_blitfb(void *fb, int pitch)
 {
-	cur_mode->ops.blitfb(fb, vsync);
+	if(pitch <= 0) {
+		pitch = cur_mode->pitch;
+	}
+	cur_mode->ops.blitfb(fb, pitch);
 }
diff --git a/vidsys.h b/vidsys.h
index cd2cfec..f019cac 100644
--- a/vidsys.h
+++ b/vidsys.h
@@ -72,6 +72,6 @@ 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);
 
-void vid_blitfb(void *fb, int vsync);
+void vid_blitfb(void *fb, int pitch);
 
 #endif	/* VIDSYS_VIDEO_H_ */
-- 
1.7.10.4