mirror of
https://github.com/isometimes/rpi4-osdev
synced 2024-11-09 20:00:40 +00:00
140 lines
3.9 KiB
C
140 lines
3.9 KiB
C
#include "wgt.h"
|
|
#include "include/mem.h"
|
|
|
|
static short start, end; /* Start and end x coords for filled line */
|
|
|
|
extern short bx, by, tx, ty; /* Clipping variables */
|
|
|
|
typedef struct {
|
|
short x, y, start, finish; /* values for filled scan line */
|
|
void *next; /* Points to next node in linked list */
|
|
} node;
|
|
|
|
static node *push (node *s, short x, short y)
|
|
{
|
|
node *newnode;
|
|
|
|
s->start = start; /* Store start of line */
|
|
s->finish = end; /* Store end of line */
|
|
|
|
newnode = (node *)malloc (sizeof (node));
|
|
/* Allocate new node */
|
|
|
|
newnode->next = (node *)s; /* Make it point to previous node */
|
|
newnode->x = x; /* Store current x and y */
|
|
newnode->y = y;
|
|
return newnode; /* Return pointer to new head node */
|
|
}
|
|
|
|
static node *pop (node *s, short *x, short *y)
|
|
{
|
|
node *headnode;
|
|
|
|
headnode = s; /* Store pointer to head node */
|
|
s = (node *)s->next; /* Go back in the chain */
|
|
*x = s->x;
|
|
/* Find out where we were last (in that row) */
|
|
*y = s->y;
|
|
start = s->start; /* Restore start and end of line */
|
|
end = s->finish;
|
|
free (headnode); /* Free head node, no longer needed */
|
|
return s; /* Return pointer to new head node */
|
|
}
|
|
|
|
void wregionfill (short x, short y)
|
|
{
|
|
short color2fill; /* Color to change */
|
|
node *s; /* Pointer to head of linked list */
|
|
block ptr; /* Used to scan through screen data */
|
|
|
|
if ((x >= tx) && (y >= ty) && (x <= bx) && (y <= by) &&
|
|
(abuf[WGT_SYS.xres * y + x] != currentcolor))
|
|
{
|
|
/* Only fill if within clipping region and color to fill isn't same as
|
|
color we're filling with */
|
|
color2fill = abuf[WGT_SYS.xres * y + x]; /* Find out color to fill */
|
|
s = (node *)malloc (sizeof (node));
|
|
/* Allocate head node */
|
|
s->next = NULL; /* No previous nodes */
|
|
s->x = x; /* Store current coords */
|
|
s->y = y;
|
|
|
|
filllabel1:
|
|
;
|
|
start = x;
|
|
/* Start of line will be our x position */
|
|
ptr = &abuf[WGT_SYS.xres * y + start - 1]; /* Make pointer to screen data */
|
|
|
|
while ((start > tx) && (*ptr == color2fill))
|
|
{
|
|
/* Now scan left until we hit a different color */
|
|
ptr--;
|
|
start--;
|
|
}
|
|
end = x;
|
|
|
|
/* End of line will be our y position */
|
|
ptr = &abuf[WGT_SYS.xres * y + end + 1];
|
|
|
|
while ((end < bx) && (*ptr == color2fill))
|
|
{
|
|
/* Scan right until we hit a different color */
|
|
end++;
|
|
ptr++;
|
|
}
|
|
|
|
memset (&abuf[WGT_SYS.xres * y + start], currentcolor, end - start + 1);
|
|
/* Fill line segment */
|
|
filllabel2:
|
|
;
|
|
if (y < by)
|
|
{
|
|
/* Proceed to check below every pixel in current line segment to see
|
|
if we can advance down a row and continue the fill */
|
|
|
|
ptr = &abuf[(y + 1) * WGT_SYS.xres + start];
|
|
for (x = start; x <= end; x++)
|
|
{
|
|
if (*ptr == color2fill)
|
|
{
|
|
/* We've found a way to 'leak' into next row, store our
|
|
position */
|
|
s = push (s, x, y + 1);
|
|
|
|
y++;
|
|
/* Now move down a row */
|
|
|
|
goto filllabel1;
|
|
}
|
|
ptr++;
|
|
}
|
|
}
|
|
|
|
/* The next area of code does the same thing, except checking upwards */
|
|
if (y > ty)
|
|
{
|
|
ptr = &abuf[(y - 1) * WGT_SYS.xres + start];
|
|
for (x = start; x <= end; x++)
|
|
{
|
|
if (*ptr == color2fill)
|
|
{
|
|
s = push (s, x, y - 1);
|
|
y--;
|
|
goto filllabel1;
|
|
}
|
|
ptr++;
|
|
}
|
|
}
|
|
|
|
/* Now we've filled all we can in one direction, move to previous node */
|
|
if (s->next != NULL)
|
|
{
|
|
s = pop (s, &x, &y);
|
|
/* Get data for previous node so we can continue scanning */
|
|
goto filllabel2;
|
|
}
|
|
|
|
/* Free the node now that we're done with it */
|
|
free (s);
|
|
}
|
|
}
|