Rewrote MiniGrLib, fixes #40.

src/Demo/Lectures/MiniGrLib.ZC

@@ -1,94 +1,136 @@
-#define VGAP_IDX		0x3C4
-#define VGAP_DATA		0x3C5
-#define VGAR_MAP_MASK	0x02
 
-U8	rev[256],		//The VGA bits are backward
-	image[640 * 480 / 8];		//We need read-modify write.
-								//0xA0000 alias memory can't be read.
- 
+U32 image[GR_HEIGHT * GR_WIDTH];
+
 U0 MGInit()
 {
-	I64 i, j;
+	MemSet(image, BLACK32, sizeof(image));
+}
 
-	MemSet(image, 0, sizeof(image));
-	MemSet(rev, 0, sizeof(rev));
-	for (i = 0; i < 256; i++)
-		for (j = 0; j < 8; j++)
-			if (Bt(&i, j))
-				Bts(&rev[i], 7 - j);
-}
- 
 U0 MGUpdate()
-{//Copy image to VGA memory
+{//Copy image to framebuffer memory
 //For better performance we could only write what's changed.
-	//0xA0000 alias is slower than normal RAM.
-	OutU8(VGAP_IDX, VGAR_MAP_MASK);
-	OutU8(VGAP_DATA, 0xF);//All color planes at once -- Black and White
-	MemCopy(text.vga_alias, image,sizeof(image)); //Alias of 0xA0000
+	MemCopy(text.fb_alias, image, sizeof(image));
 }
- 
+
 U0 MGPlot(I64 x,I64 y)
 {
-	if (0 <= x < 640 && 0 <= y < 480)
-		Bts(image,y * 640 + x ^ 7);
+	if (0 <= x < GR_WIDTH && 0 <= y < GR_HEIGHT)
+		image[x + y * GR_WIDTH] = WHITE32;
 }
- 
-U0 MGHLine(I64 x1, I64 x2, I64 y)
-{//Warning!  No clipping
-//For performance, we do as many whole-bytes as possible.
-	U8 *ptr;
-	I64 i, w, leading, trailing, whole_bytes;
 
+U0 MGHLine(I64 x1, I64 x2, I64 y)
+{//No clipping
+	I64 x;
+
+	if (y >= GR_HEIGHT)
+		return;
 	if (x2 < x1)
 		SwapI64(&x1, &x2);
-	ptr = image + y * 640 / 8 + x1 >> 3;
-	w = x2 - x1 + 1;
-	leading = 8 - x1 & 7;
-	trailing = (x2 + 1) & 7;
-	if (leading + trailing > w)
-		*ptr |= rev[(0xFF00 >> leading & (0x00FF << trailing) >> 8)];
-	else
+	if (x1 < 0)
+		x1 = 0;
+	if (x2 < x1)
+		SwapI64(&x1, &x2);
+	x = x1;
+
+	while (x <= x2 && x < GR_WIDTH)
 	{
-		whole_bytes = (w - leading - trailing) >> 3;
-		if (leading)
-			*ptr++ |= rev[(0xFF00 >> leading) & 0xFF];
-		for (i = 0; i < whole_bytes; i++)
-			*ptr++ = 0xFF;
-		if (trailing)
-			*ptr++ |= rev[(0x00FF << trailing) >> 8];
+		image[x + y * GR_WIDTH] = WHITE32;
+		x++;
 	}
 }
  
 U0 MGLine(I64 x1,I64 y1,I64 x2,I64 y2)
-{//Warning!  No clipping
-	I64 dx=x2-x1,dy=y2-y1;
+{//No clipping
+	I64 x_start, x_end, y_start, y_end, x, y, dx, dy, c;
 
-	x1 <<= 32; x2 <<= 32;
-	y1 <<= 32; y2 <<= 32;
-	if (AbsI64(dx) > AbsI64(dy))
+	c = 0;
+	x_start = MinI64(x1, x2);
+
+	if (x_start == x1)
 	{
-		dy = dy << 32 / AbsI64(dx);
-		dx = SignI64(dx) << 32;
-		while (x1 != x2)
+		y_start = y1;
+		x_end = x2;
+		y_end = y2;
+	}
+	else // x2
+	{
+		y_start = y2;
+		x_end = x1;
+		y_end = y1;
+	}
+
+	x = x_start;
+	y = y_start;
+	dx = x_end - x_start;
+
+	if (y_end < y_start)
+	{
+		dy = y_start - y_end;
+
+		if (dx >= dy)
 		{
-			MGPlot(x1.i32[1], y1.i32[1]);
-			x1 += dx; y1 += dy;
+			while (x <= x_end)
+			{
+				MGPlot(x, y);
+				c += dy;
+				if (c >= dx)
+				{
+					c -= dx;
+					y--;
+				}
+				x++;
+			}
+		}
+		else
+		{
+			while (y > y_end)
+			{
+				MGPlot(x, y);
+				c += dx;
+				if (c >= dy)
+				{
+					c -= dy;
+					x++;
+				}
+				y--;
+			}
 		}
 	}
 	else
 	{
-		dx = dx << 32 / AbsI64(dy);
-		dy = SignI64(dy) << 32;
-		while (y1 != y2)
+		dy = y_end - y_start;
+
+		if (dx >= dy)
 		{
-			MGPlot(x1.i32[1], y1.i32[1]);
-			x1 += dx;
-			y1 += dy;
+			while (x <= x_end)
+			{
+				MGPlot(x, y);
+				c += dy;
+				if (c >= dx)
+				{
+					c -= dx;
+					y++;
+				}
+				x++;
+			}
+		}
+		else
+		{
+			while (y <= y_end)
+			{
+				MGPlot(x, y);
+				c += dx;
+				if (c >= dy)
+				{
+					c -= dy;
+					x++;
+				}
+				y++;
+			}
 		}
 	}
-	MGPlot(x1.i32[1], y1.i32[1]);
 }
- 
+
 U0 MGCircle(I64 x, I64 y, F64 r)
 {
 	F64 s, c, x1, y1, x2, y2;
@@ -118,31 +160,34 @@ U0 MGCircle(I64 x, I64 y, F64 r)
 		MGPlot(x+x1,y+y1);
 	}
 }
- 
- 
+
 U0 MiniGrLibDemo()
 {
 	I64 i;
+
 	MGInit;
 
 	for (i = 0; i < 100; i++)
-		MGHLine(200 + i, 400 + i, 300 + i);
+		MGHLine(200 + i, 400 + i, 400 + i);
 
-	for (i = 0; i < 500; i += 10)
-		MGLine(i, 0, 0, 480 - i);
+	for (i = 0; i < GR_HEIGHT + 20; i += 10)
+		MGLine(i, 0, 0, GR_HEIGHT - i);
 
 	for (i = 0; i < 300; i += 4)
-		MGCircle(200, 100 + i, i);
+		MGCircle(400, 200 + i, i);
+
 	MGUpdate;
 	Busy(1500000);
+
+
 /*
 We are returning graphics to normal operations under ZealOS.
 It is not normal to by-pass the ZealOS graphcis routines.
-The ZealOS graphics don't know VGA has changed.
-This bit tells ZealOS to update whole screen.
+The ZealOS graphics don't know the framebuffer has changed.
+This function tells ZealOS to update whole screen.
 */
-	//<CTRL-ALT-v> will flush screen VGA cache.
+	//<CTRL-ALT-v> will flush screen VGA cache and un-set framebuffer-busy bit.
 	LFBFlush;
 }
  
-MiniGrLibDemo;
+MiniGrLibDemo;

src/Doc/ChangeLog.DD

@@ -1,4 +1,7 @@
 $WW,1$$FG,5$$TX+CX,"ChangeLog"$$FG$
+$IV,1$----03/17/23 17:44:24----$IV,0$
+* Rewrote $LK+PU,"MiniGrLib",A="FI:::/Demo/Lectures/MiniGrLib.ZC"$, replaced old VGA-specific code to work with 32-bit framebuffer.
+
 $IV,1$----03/14/23 03:23:46----$IV,0$
 * Created %o Bool $LK+PU,"StrPrint",A="FF:::/Kernel/StrPrint.ZC,'o':"$ format code, updated $LK+PU,"Print.DD",A="FI:::/Doc/Print.DD"$ with new %o code and previously undocumented format codes.