Detect mouse in an area?
BlitzMax Forums/BlitzMax Programming/Detect mouse in an area?
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| Hi, I need a little function where I can specify 4 points and if the mouse crosses into the area the 4 points set out I will return true. Like : MouseInArea(point1,point2,point3,point4) heres a pick to explain a little more, I could attack am image to the mouse pointer and use image collide but that seems messy, must be a way to know if the mouse moves between the 4 points.  |
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| I think you're looking for point in poly and there's a few in the Code Archives. One two three Might be some more as well. |
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| wohoo.. great just what I was after.. thanks |
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| Instead of using collideimage and attaching an image to the mouse, you can use CollideRect( MouseX(), MouseY(), 1, 1, CollisionLayers, WriteLayers) to see if the mouse is overlapping an image object. This creates a 1 pixel by 1 pixel rectangle at the mouse pointer and checks it for collisions. Of course, that would only work if your "Play Game" sign above was a separate image and not part of the surrounding image. If it's part of the surrounding image, the methods Tony linked to are your best bet. |
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| Hi, Nice idea but still more work than is really required for this simple task. I have tried skidracers pointinpoly but cant seem to get it to work, heres my code.. any 1 see where I am going wrong? For this test im just checking a 64x64 sqaure in the top left, plotting the points anti-clockwise (tried all other directions also) cant seem to get it to respond though =( Graphics 800,600,0,60 SetBlend ALPHABLEND Repeat ; cls If InsideQuad(mousex(),mousey(),0,0,0,64,64,64,64,0)=1 Then DrawText "wohoo",200,200 Else DrawText "doh!",200,200 DrawText MouseX()+"/"+Mousey(),10,10 Flip ; Until KeyDown(KEY_ESCAPE) ; End Function dot(x0,y0,x1,y1,x2,y2) Return (x1-x0)*(y2-y1)-(x2-x1)*(y1-y0) End Function Function InsideQuad(px,py,x0,y0,x1,y1,x2,y2,x3,y3) If dot(x0,y0,x1,y1,px,py)>0 If dot(x1,y1,x2,y2,px,py)>0 If dot(x2,y2,x3,y3,px,py)>0 If dot(x3,y3,x0,y0,px,py)>0 Return True EndIf EndIf EndIf EndIf End Function |
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SculptureOfSoul. Ha looks like I should have used that, I made a 1 pixel image as my mouse pointer and used CollideImage! haha. [edit] bah, it didn't work and I've no idea why...I had thisCollideImage(Pixel.Image, mx, my, 0, 1, 0) and I changed it for this... CollideRect(mx,my,1,1,1,0) oh well. |
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| edit: deleted because my mistake was trivial. |
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| Oops, I just put back my old code and now that doesn't work so I must have broken something. Please ignore previous post. |
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| edit: deleted since content is no longer relevant. :P |
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found this version in archives.. works a treat =DGraphics 800,600,0,60 SetBlend ALPHABLEND Repeat ; cls If GenericPointInQuad(mousex(),mousey(),0,0,64,0,64,64,0,64)=1 Then DrawText "wohoo",200,200 Else DrawText "doh!",200,200 DrawText MouseX()+"/"+Mousey(),10,10 Flip ; Until KeyDown(KEY_ESCAPE) ; End Function GenericPointInQuad (x, y, x0, y0, x1, y1, x2, y2, x3, y3) ' clockwise If ((y - y0) * (x1 - x0)) - ((x - x0) * (y1 - y0)) <= 0 Then Return 0 If ((y - y1) * (x2 - x1)) - ((x - x1) * (y2 - y1)) <= 0 Then Return 0 If ((y - y2) * (x3 - x2)) - ((x - x2) * (y3 - y2)) <= 0 Then Return 0 If ((y - y3) * (x0 - x3)) - ((x - x3) * (y0 - y3)) <= 0 Then Return 0 Return True End Function |
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| snaffled. |
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