Hello gamers, I''m creating a map editor. The user will be able to select what structures(trees,houses,walls,etc) he wants to place on the screen from the toolbar. When the user makes the selection the bitmap or image will be placed on the screen. My question is once the bitmap or image is placed on the screen how do I move it around the screen so that I can place it where I want using the mouse? Next question: I want to create a wall in the the map editor window. I want to be able to click the mouse in two points and fill the space between the two points with a wall, how would I go about doing this? The wall will be probably be a defined size just like all of my other structures. Thanks Gamers, casper

assuming you're speaking of 2d:

the easiest and most straight forward way would be to maintain a an xy position and z-order for all of your images. this way, you know what order in which to draw them. (groundplane = 0, etc.)

the simplest way of determining which images is at the mouse position is to brute force it (pseudocode):

for (each image in the array imgarray[]) {
if (
(mouse.x > imgarray[index].x) &&
(mouse.x < (imgarray[index].x + imgarray[index].width)) &&
(mouse.y > imgarray[index].y) &&
(mouse.y < (imgarray[index].y + imgarray[index].height))
)
{
//we have a winner!
int selectedimg = index;
break;
}
}

you can optimize the above (which doesn't take z into account btw) brute force pseudocode by ordering your images by location, and arbitrarily building a list of nearby images to the mouse cursor. along the same lines, you might maintain a list of images that are visible (since you only draw those, right?) and check against that.

Edited by - revolver on 3/18/00 1:52:38 PM

Would this pseudo code apply for bitmap images too?

quote:

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Original post by revolver

assuming you''re speaking of 2d:

the easiest and most straight forward way would be to maintain a an xy position and z-order for all of your images. this way, you know what order in which to draw them. (groundplane = 0, etc.)

the simplest way of determining which images is at the mouse position is to brute force it (pseudocode):

for (each image in the array imgarray[]) {
if (
(mouse.x > imgarray[index].x) &&
(mouse.x < (imgarray[index].x + imgarray[index].width)) &&
(mouse.y > imgarray[index].y) &&
(mouse.y < (imgarray[index].y + imgarray[index].height))
)
{
//we have a winner!
int selectedimg = index;
break;
}
}

you can optimize the above (which doesn''t take z into account btw) brute force pseudocode by ordering your images by location, and arbitrarily building a list of nearby images to the mouse cursor. along the same lines, you might maintain a list of images that are visible (since you only draw those, right?) and check against that.

Edited by - revolver on 3/18/00 1:52:38 PM

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Hey revolver would this pseudocode apply to bitmap images as well?

I believe the imgarray[x] is referring to the bitmap?

it should work with any image you have in the array, as long as you store the x and y position for each.

imgarray[] is just an array of images (bitmaps). index is the current one it''s looking at, and increased every time the for loop rolls over. thus, imgarray[index] will return a certain image. imgarray[index].x gets the x position, and so on.