I am creating a nice level editor for my game now, and I need to draw a 50x50 square grid in four of my child windows. How could I do this considering the fact that the window size could change on a different users computer? My current formula is below, but it will NOT work!

RECT pr;
GetClientRect(GetDlgItem(pwnd, ID_DATAVIEW), &pr);

for(int loop = 1; loop < 51; loop++)
{
MoveToEx(screen, (pr.right / 50) * loop, 0, NULL);
LineTo(screen, (pr.right / 50) * loop, pr.bottom);
MoveToEx(screen, 0, (pr.bottom / 50) * loop, NULL);
LineTo(screen, pr.right, (pr.bottom / 50) * loop);
}

I thought that would work, but it doesn't. Any ideas? Thanks to any and all who help.

<br>-Sephiroth

: I am creating a nice level editor for my game now, and I need to draw a 50x50 square grid in four of my child windows. How could I do this considering the fact that the window size could change on a different users computer? My current formula is below, but it will NOT work!
:
: RECT pr;
: GetClientRect(GetDlgItem(pwnd, ID_DATAVIEW), &pr);
:
: for(int loop = 1; loop < 51; loop++)
: {
: MoveToEx(screen, (pr.right / 50) * loop, 0, NULL);
: LineTo(screen, (pr.right / 50) * loop, pr.bottom);
: MoveToEx(screen, 0, (pr.bottom / 50) * loop, NULL);
: LineTo(screen, pr.right, (pr.bottom / 50) * loop);
: }
:
Your code is faulty because the order of the calculations is incorrect.
Use pr.right*loop/50 or you'll have problem.

OK, I'll try that when I get home. I'm playing with the T1 here at work now (=. The way I was thinking was this:

Width of window / 50 pixels == Exact length of each grid
Exact length of each grid * Loop == Where to draw line

Never even thought about using a decimal answer since it will give me a more accurate position. Thanks for the help man!



-Sephiroth

No go. The formula you gave me doesn't draw anything in the window :/. I have another idea, and I'll try it now. If you have any other ideas, lemme' know.



-Sephiroth

warning: not compiled

#define ROWS 50
#define COLS 50

void DrawGrid(HDC hdc, const RECT* rect)
{
for(int x = 0; x < COLS; x++)
{
MoveToEx(hdc, x, 0, NULL);
LineTo(hdc, x, rect->bottom);
}
for(int y = 0; y < ROWS; y++)
{
MoveToEx(hdc, 0, y, NULL);
LineTo(hdc, rect->right, y, NULL);
}
}

and some other not compiled code...
void HitTest(int x, int y, const RECT* rect, int *row, int *col)
{
*col = MulDiv(x, COLS, rect->right);
*row = MulDiv(y, ROWS, rect->bottom);
}


: I am creating a nice level editor for my game now, and I need to draw a 50x50 square grid in four of my child windows. How could I do this considering the fact that the window size could change on a different users computer? My current formula is below, but it will NOT work!
:
: RECT pr;
: GetClientRect(GetDlgItem(pwnd, ID_DATAVIEW), &pr);
:
: for(int loop = 1; loop < 51; loop++)
: {
: MoveToEx(screen, (pr.right / 50) * loop, 0, NULL);
: LineTo(screen, (pr.right / 50) * loop, pr.bottom);
: MoveToEx(screen, 0, (pr.bottom / 50) * loop, NULL);
: LineTo(screen, pr.right, (pr.bottom / 50) * loop);
: }
:
: I thought that would work, but it doesn't. Any ideas? Thanks to any and all who help.
:
: -Sephiroth
:

This is just a draft, it may work...

int stepX = <width> / 50;
int stepY = <height> / 50;
int x = stepX, y = stepY;
for (int loop = 1; loop <= 50; ++loop, x += stepX, y += stepY)
{
    MoveToEx(screen, 0, y, NULL);
    LineTo  (screen, <width>, y);
    MoveToEx(screen, x, 0, NULL);
    LineTo  (screen, x, <height>));
}

This should draw 49 parallel lines as you want to do. The resulting size, however, will be rounded up to a multiple of 50 (if want better, use floats).
________
ColdShine

Thanks, but I figured it out. Here's the basic run-down:

RECT pr;

for(int loop = (pr.right / 50); loop < pr.right; pr.right += (pr.right / 50))
{
MoveToEx(screen, loop, 0, NULL);
LineTo(screen, loop, pr.bottom);
MoveToEx(screen, 0, loop, NULL);
LineTo(screen, pr.right, loop);
}

A bit more simple than I thought. Thanks for the help though, I got the idea from the examples you showed me. Thanks to all of ya'!



-Sephiroth