Question

I wrote a gui where a user draws something in a (640×480) window. It makes that drawing into a set of points stored in a Vector array. Now, how do I translate those set of points to the origin (0,0 top left corner of the window) or put it at a specified pos? The width and height of the window I want it in is also 640×480.

After that is solved, how do you scale that new set of points to a size I want?

UPDATE 1

I solved the scale issue, but not the positioning issue. The drawing is not going where I tell it to be. Code below of what I have so far.

float scaleX = (float)width/boundingPoints.width;
float scaleY = (float)height/boundingPoints.height;
for(int i = 0; i < cg_points.size()-1; i++){
    Point p1 = cg_points.get(i);
    Point p2 = cg_points.get(i+1);
    g.drawLine((int)(p1.x*scaleX) + pos.x, (int)(p1.y*scaleY) + pos.y, (int)(p2.x*scaleX) + pos.x, (int)(p2.y*scaleY) + pos.y);
}

I want the drawing to start at where pos [x, y] is. What is currently the problem is this. It does follow what pos.x and pos.y does, but it is way off and not starting at pos[x,y].

Here is a screen shot of the issue

As you can see from the picture, the box is where the star is supposed to be. The scaling is right as you can see, just not the pos. That is because the points in the drawing may NOT start at (0,0).

Any suggestions?

Thanks!

Answer 1

So I solved it…YAY!!! Here is the code below in case you run into the same issue as I had.

    float scaleX = (float)width/boundingPoints.width;
    float scaleY = (float)height/boundingPoints.height;
    int bx = boundingPoints.x;
    int by = boundingPoints.y;
    for(int i = 0; i < cg_points.size()-1; i++){
            Point p1 = cg_points.get(i);
            Point p2 = cg_points.get(i+1);
            int x1 = (int) ((p1.x-bx)*scaleX);
            x1 += pos.x;
            int y1 = (int) ((p1.y-by)*scaleY);
            y1 += pos.y;
            int x2 = (int) ((p2.x-bx)*scaleX);
            x2 += pos.x;
            int y2 = (int) ((p2.y-by)*scaleY);
            y2 += pos.y;

            g.drawLine(x1, y1, x2, y2);
        }