vt(4): Store a rectangle for the drawable area, not just the top-left corner

This allows backends to verify they do not draw outside of this area.
This fixes a bug in vt_vga where the text was happily drawn over the
right and bottom margins, when using the Gallant font.

MFC after:	1 week

6 files changed, 68 insertions, 51 deletions

diff --git a/sys/dev/fb/creator_vt.c b/sys/dev/fb/creator_vt.c
index 6bed29d..18a42b9 100644
--- a/sys/dev/fb/creator_vt.c
+++ b/sys/dev/fb/creator_vt.c
@@ -236,8 +236,10 @@ creatorfb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
 		for (col = area->tr_begin.tp_col; col < area->tr_end.tp_col;
 		    ++col) {
-			x = col * vf->vf_width + vw->vw_offset.tp_col;
-			y = row * vf->vf_height + vw->vw_offset.tp_row;
+			x = col * vf->vf_width +
+			    vw->vw_draw_area.tr_begin.tp_col;
+			y = row * vf->vf_height +
+			    vw->vw_draw_area.tr_begin.tp_row;
 
 			c = VTBUF_GET_FIELD(&vw->vw_buf, row, col);
 			pattern = vtfont_lookup(vf, c);
@@ -257,13 +259,13 @@ creatorfb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	term_rect_t drawn_area;
 
 	drawn_area.tr_begin.tp_col = area->tr_begin.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_begin.tp_row = area->tr_begin.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 	drawn_area.tr_end.tp_col = area->tr_end.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_end.tp_row = area->tr_end.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 
 	if (vt_is_cursor_in_area(vd, &drawn_area)) {
 		creatorfb_bitblt_bitmap(vd, vw,
diff --git a/sys/dev/vt/hw/fb/vt_fb.c b/sys/dev/vt/hw/fb/vt_fb.c
index 04023c0..3cae588 100644
--- a/sys/dev/vt/hw/fb/vt_fb.c
+++ b/sys/dev/vt/hw/fb/vt_fb.c
@@ -331,8 +331,10 @@ vt_fb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
 		for (col = area->tr_begin.tp_col; col < area->tr_end.tp_col;
 		    ++col) {
-			x = col * vf->vf_width + vw->vw_offset.tp_col;
-			y = row * vf->vf_height + vw->vw_offset.tp_row;
+			x = col * vf->vf_width +
+			    vw->vw_draw_area.tr_begin.tp_col;
+			y = row * vf->vf_height +
+			    vw->vw_draw_area.tr_begin.tp_row;
 
 			c = VTBUF_GET_FIELD(&vw->vw_buf, row, col);
 			pattern = vtfont_lookup(vf, c);
@@ -352,13 +354,13 @@ vt_fb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	term_rect_t drawn_area;
 
 	drawn_area.tr_begin.tp_col = area->tr_begin.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_begin.tp_row = area->tr_begin.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 	drawn_area.tr_end.tp_col = area->tr_end.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_end.tp_row = area->tr_end.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 
 	if (vt_is_cursor_in_area(vd, &drawn_area)) {
 		vt_fb_bitblt_bitmap(vd, vw,
diff --git a/sys/dev/vt/hw/ofwfb/ofwfb.c b/sys/dev/vt/hw/ofwfb/ofwfb.c
index 2a31d16..835a07d 100644
--- a/sys/dev/vt/hw/ofwfb/ofwfb.c
+++ b/sys/dev/vt/hw/ofwfb/ofwfb.c
@@ -209,8 +209,10 @@ ofwfb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
 		for (col = area->tr_begin.tp_col; col < area->tr_end.tp_col;
 		    ++col) {
-			x = col * vf->vf_width + vw->vw_offset.tp_col;
-			y = row * vf->vf_height + vw->vw_offset.tp_row;
+			x = col * vf->vf_width +
+			    vw->vw_draw_area.tr_begin.tp_col;
+			y = row * vf->vf_height +
+			    vw->vw_draw_area.tr_begin.tp_row;
 
 			c = VTBUF_GET_FIELD(&vw->vw_buf, row, col);
 			pattern = vtfont_lookup(vf, c);
@@ -230,13 +232,13 @@ ofwfb_bitblt_text(struct vt_device *vd, const struct vt_window *vw,
 	term_rect_t drawn_area;
 
 	drawn_area.tr_begin.tp_col = area->tr_begin.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_begin.tp_row = area->tr_begin.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 	drawn_area.tr_end.tp_col = area->tr_end.tp_col * vf->vf_width +
-	    vw->vw_offset.tp_col;
+	    vw->vw_draw_area.tr_begin.tp_col;
 	drawn_area.tr_end.tp_row = area->tr_end.tp_row * vf->vf_height +
-	    vw->vw_offset.tp_row;
+	    vw->vw_draw_area.tr_begin.tp_row;
 
 	if (vt_is_cursor_in_area(vd, &drawn_area)) {
 		ofwfb_bitblt_bitmap(vd, vw,
diff --git a/sys/dev/vt/hw/vga/vt_vga.c b/sys/dev/vt/hw/vga/vt_vga.c
index e21a9a1..135845d 100644
--- a/sys/dev/vt/hw/vga/vt_vga.c
+++ b/sys/dev/vt/hw/vga/vt_vga.c
@@ -556,16 +556,17 @@ vga_bitblt_one_text_pixels_block(struct vt_device *vd,
 	memset(pattern_2colors, 0, sizeof(pattern_2colors));
 	memset(pattern_ncolors, 0, sizeof(pattern_ncolors));
 
-	if (i < vw->vw_offset.tp_col) {
+	if (i < vw->vw_draw_area.tr_begin.tp_col) {
 		/*
 		 * i is in the margin used to center the text area on
 		 * the screen.
 		 */
 
-		i = vw->vw_offset.tp_col;
+		i = vw->vw_draw_area.tr_begin.tp_col;
 	}
 
-	while (i < x + VT_VGA_PIXELS_BLOCK) {
+	while (i < x + VT_VGA_PIXELS_BLOCK &&
+	    i < vw->vw_draw_area.tr_end.tp_col) {
 		/*
 		 * Find which character is drawn on this pixel in the
 		 * pixels block.
@@ -573,8 +574,8 @@ vga_bitblt_one_text_pixels_block(struct vt_device *vd,
 		 * While here, record what colors it uses.
 		 */
 
-		col = (i - vw->vw_offset.tp_col) / vf->vf_width;
-		row = (y - vw->vw_offset.tp_row) / vf->vf_height;
+		col = (i - vw->vw_draw_area.tr_begin.tp_col) / vf->vf_width;
+		row = (y - vw->vw_draw_area.tr_begin.tp_row) / vf->vf_height;
 
 		c = VTBUF_GET_FIELD(vb, row, col);
 		src = vtfont_lookup(vf, c);
@@ -605,11 +606,15 @@ vga_bitblt_one_text_pixels_block(struct vt_device *vd,
 		 * character.
 		 */
 
-		src_x = i - (col * vf->vf_width + vw->vw_offset.tp_col);
-		x_count = min(
-		    (col + 1) * vf->vf_width + vw->vw_offset.tp_col,
-		    x + VT_VGA_PIXELS_BLOCK);
-		x_count -= col * vf->vf_width + vw->vw_offset.tp_col;
+		src_x = i -
+		    (col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col);
+		x_count = min(min(
+		    (col + 1) * vf->vf_width +
+		    vw->vw_draw_area.tr_begin.tp_col,
+		    x + VT_VGA_PIXELS_BLOCK),
+		    vw->vw_draw_area.tr_end.tp_col);
+		x_count -= col * vf->vf_width +
+		    vw->vw_draw_area.tr_begin.tp_col;
 		x_count -= src_x;
 
 		/* Copy a portion of the character. */
@@ -643,14 +648,16 @@ vga_bitblt_one_text_pixels_block(struct vt_device *vd,
 		unsigned int dst_x, src_y, dst_y, y_count;
 
 		cursor = vd->vd_mcursor;
-		mx = vd->vd_mx_drawn + vw->vw_offset.tp_col;
-		my = vd->vd_my_drawn + vw->vw_offset.tp_row;
+		mx = vd->vd_mx_drawn + vw->vw_draw_area.tr_begin.tp_col;
+		my = vd->vd_my_drawn + vw->vw_draw_area.tr_begin.tp_row;
 
 		/* Compute the portion of the cursor we want to copy. */
 		src_x = x > mx ? x - mx : 0;
 		dst_x = mx > x ? mx - x : 0;
-		x_count = min(
-		    min(cursor->width - src_x, x + VT_VGA_PIXELS_BLOCK - mx),
+		x_count = min(min(min(
+		    cursor->width - src_x,
+		    x + VT_VGA_PIXELS_BLOCK - mx),
+		    vw->vw_draw_area.tr_end.tp_col - mx),
 		    VT_VGA_PIXELS_BLOCK);
 
 		/*
@@ -725,10 +732,10 @@ vga_bitblt_text_gfxmode(struct vt_device *vd, const struct vt_window *vw,
 
 	col = area->tr_begin.tp_col;
 	row = area->tr_begin.tp_row;
-	x1 = (int)((col * vf->vf_width + vw->vw_offset.tp_col)
+	x1 = (int)((col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col)
 	     / VT_VGA_PIXELS_BLOCK)
 	    * VT_VGA_PIXELS_BLOCK;
-	y1 = row * vf->vf_height + vw->vw_offset.tp_row;
+	y1 = row * vf->vf_height + vw->vw_draw_area.tr_begin.tp_row;
 
 	/*
 	 * Compute the bottom right pixel position, again, aligned with
@@ -740,19 +747,15 @@ vga_bitblt_text_gfxmode(struct vt_device *vd, const struct vt_window *vw,
 
 	col = area->tr_end.tp_col;
 	row = area->tr_end.tp_row;
-	x2 = (int)((col * vf->vf_width + vw->vw_offset.tp_col
+	x2 = (int)((col * vf->vf_width + vw->vw_draw_area.tr_begin.tp_col
 	      + VT_VGA_PIXELS_BLOCK - 1)
 	     / VT_VGA_PIXELS_BLOCK)
 	    * VT_VGA_PIXELS_BLOCK;
-	y2 = row * vf->vf_height + vw->vw_offset.tp_row;
+	y2 = row * vf->vf_height + vw->vw_draw_area.tr_begin.tp_row;
 
-	/*
-	 * Clip the area to the screen size.
-	 *
-	 * FIXME: Take vw_offset into account.
-	 */
-	x2 = min(x2, vd->vd_width - 1);
-	y2 = min(y2, vd->vd_height - 1);
+	/* Clip the area to the screen size. */
+	x2 = min(x2, vw->vw_draw_area.tr_end.tp_col);
+	y2 = min(y2, vw->vw_draw_area.tr_end.tp_row);
 
 	/*
 	 * Now, we take care of N pixels line at a time (the first for
diff --git a/sys/dev/vt/vt.h b/sys/dev/vt/vt.h
index 55c5b18..89d3de4 100644
--- a/sys/dev/vt/vt.h
+++ b/sys/dev/vt/vt.h
@@ -258,7 +258,7 @@ struct vt_window {
 	struct terminal		*vw_terminal;	/* (c) Terminal. */
 	struct vt_buf		 vw_buf;	/* (u) Screen buffer. */
 	struct vt_font		*vw_font;	/* (d) Graphical font. */
-	term_pos_t		 vw_offset;	/* (?) Pixel offset. */
+	term_rect_t		 vw_draw_area;	/* (?) Drawable area. */
 	unsigned int		 vw_number;	/* (c) Window number. */
 	int			 vw_kbdmode;	/* (?) Keyboard mode. */
 	char			*vw_kbdsq;	/* Escape sequence queue*/
diff --git a/sys/dev/vt/vt_core.c b/sys/dev/vt/vt_core.c
index 32887c8..ae1e97b 100644
--- a/sys/dev/vt/vt_core.c
+++ b/sys/dev/vt/vt_core.c
@@ -828,8 +828,8 @@ vt_is_cursor_in_area(const struct vt_device *vd, const term_rect_t *area)
 	 * We use the cursor position saved during the current refresh,
 	 * in case the cursor moved since.
 	 */
-	mx = vd->vd_mx_drawn + vd->vd_curwindow->vw_offset.tp_col;
-	my = vd->vd_my_drawn + vd->vd_curwindow->vw_offset.tp_row;
+	mx = vd->vd_mx_drawn + vd->vd_curwindow->vw_draw_area.tr_begin.tp_col;
+	my = vd->vd_my_drawn + vd->vd_curwindow->vw_draw_area.tr_begin.tp_row;
 
 	x1 = area->tr_begin.tp_col;
 	y1 = area->tr_begin.tp_row;
@@ -1202,8 +1202,8 @@ vt_set_border(struct vt_window *vw, struct vt_font *vf, term_color_t c)
 
 	x = vd->vd_width - 1;
 	y = vd->vd_height - 1;
-	off_x = vw->vw_offset.tp_col;
-	off_y = vw->vw_offset.tp_row;
+	off_x = vw->vw_draw_area.tr_begin.tp_col;
+	off_y = vw->vw_draw_area.tr_begin.tp_row;
 
 	/* Top bar. */
 	if (off_y > 0)
@@ -1257,9 +1257,17 @@ vt_change_font(struct vt_window *vw, struct vt_font *vf)
 
 	vt_termsize(vd, vf, &size);
 	vt_winsize(vd, vf, &wsz);
-	/* Save offset to font aligned area. */
-	vw->vw_offset.tp_col = (vd->vd_width % vf->vf_width) / 2;
-	vw->vw_offset.tp_row = (vd->vd_height % vf->vf_height) / 2;
+
+	/*
+	 * Compute the drawable area, so that the text is centered on
+	 * the screen.
+	 */
+	vw->vw_draw_area.tr_begin.tp_col = (vd->vd_width % vf->vf_width) / 2;
+	vw->vw_draw_area.tr_begin.tp_row = (vd->vd_height % vf->vf_height) / 2;
+	vw->vw_draw_area.tr_end.tp_col = vw->vw_draw_area.tr_begin.tp_col +
+	    vd->vd_width / vf->vf_width * vf->vf_width;
+	vw->vw_draw_area.tr_end.tp_row = vw->vw_draw_area.tr_begin.tp_row +
+	    vd->vd_height / vf->vf_height * vf->vf_height;
 
 	/* Grow the screen buffer and terminal. */
 	terminal_mute(tm, 1);