blob: 35f857af07938d1f4bdbc88865c95635188f9374 [file] [log] [blame]
// Virtual software based cursor support
//
// Copyright (C) 2014-2016 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "biosvar.h" // GET_BDA
#include "vgabios.h" // handle_gfx_op
// Draw/undraw a cursor on the framebuffer by xor'ing the cursor cell
static void
gfx_set_swcursor(struct vgamode_s *vmode_g, int enable, struct cursorpos cp)
{
u16 cursor_type = get_cursor_shape();
u8 start = cursor_type >> 8, end = cursor_type & 0xff;
struct gfx_op op;
init_gfx_op(&op, vmode_g);
op.x = cp.x * 8;
int cheight = GET_BDA(char_height);
op.y = cp.y * cheight + start;
int i;
for (i = start; i < cheight && i <= end; i++, op.y++) {
op.op = GO_READ8;
handle_gfx_op(&op);
int j;
for (j = 0; j < 8; j++)
op.pixels[j] ^= 0x07;
op.op = GO_WRITE8;
handle_gfx_op(&op);
}
}
// Draw/undraw a cursor on the screen
void
vgafb_set_swcursor(int enable)
{
if (!vga_emulate_text())
return;
u8 flags = GET_BDA_EXT(flags);
if (!!(flags & BF_SWCURSOR) == enable)
// Already in requested mode.
return;
struct vgamode_s *vmode_g = get_current_mode();
if (!vmode_g)
return;
struct cursorpos cp = get_cursor_pos(GET_BDA(video_page));
if (cp.x >= GET_BDA(video_cols) || cp.y > GET_BDA(video_rows)
|| GET_BDA(cursor_type) >= 0x2000)
// Cursor not visible
return;
SET_BDA_EXT(flags, (flags & ~BF_SWCURSOR) | (enable ? BF_SWCURSOR : 0));
if (GET_GLOBAL(vmode_g->memmodel) != MM_TEXT) {
gfx_set_swcursor(vmode_g, enable, cp);
return;
}
// In text mode, swap foreground and background attributes for cursor
void *dest_far = text_address(cp) + 1;
u8 attr = GET_FARVAR(GET_GLOBAL(vmode_g->sstart), *(u8*)dest_far);
attr = (attr >> 4) | (attr << 4);
SET_FARVAR(GET_GLOBAL(vmode_g->sstart), *(u8*)dest_far, attr);
}