How to get start/end point of a dm-script line annotation (Component)? - annotations

Question

I want to use:
Component NewLineAnnotation( Number top, Number left, Number bottom, Number right )
The problem is that the line always runs in the direction from the top-left to the bottom-right.
However, I need the line to go from bottom-right to top-left.
And I also need to be able to get the accurate direction from an existing one.
It seems silly that the command is not:
Component NewLineAnnotation( Number start_x, Number start_y, Number end_x, Number end_y )
but surely there is a way to get the direction of the line annotation?
void ComponentGetRect( Component comp, NumberVariable top, NumberVariable left, NumberVariable bottom, NumberVariable right )
does not have such a detail.

Answer 1

Given the details in earlier great answer I looked more and found this to be the situation - I am using GMS 3.
The command for creating a line as a component via:
NewLineAnnotation( Number top, Number left, Number bottom, Number right )
could be described better as:
NewLineAnnotation( Number sX, Number sY, Number eX, Number eY )
But there is another source of potential confusion. When looking for the Get() command for the coordinates, these commands are listed:
void ComponentGetBoundingRect( Component comp, NumberVariable t, NumberVariable l, NumberVariable b, NumberVariable r )
void ComponentGetRect( Component comp, NumberVariable top, NumberVariable left, NumberVariable bottom, NumberVariable right )
void ComponentGetRectInView( Component comp, NumberVariable top, NumberVariable left, NumberVariable bottom, NumberVariable right )
All 3 commands claim the order: top, left, bottom, right, but only the first and the last commands do. The second command could again be better described by
ComponentGetRect(Number sX, Number sY, Number eX, Number eY)
I had mixed up the command NewLineAnnotation() with ComponentGetBoundingRect() and that caused some real issues. I feel a better description in the manual might help avoid such issues.
As a summary, here is some code I used to demonstrate the different functionalities to myself.
image front := CreateFloatImage("", 800, 800)
front.setZoom(.4)
front.ShowImage()
component frontComponent = front.ImageGetImageDisplay(0)
component solid_Line_orange = NewLineAnnotation(700, 10, 500, 200);
frontComponent.ComponentAddChildAtEnd(solid_Line_orange)
solid_Line_orange.ComponentSetForegroundColor(1,.66,0);
component solid_Line_white = NewLineAnnotation(500, 10, 700, 200);
frontComponent.ComponentAddChildAtEnd(solid_Line_white)
number sx, sy, ex, ey
number l_top, l_left, l_buttom, l_right
solid_Line_orange.ComponentGetRect( l_top, l_left, l_buttom, l_right );
Result("\n\n")
Result("using: ComponentGetRectangle();\t actual convention: (start_x, start_y, end_x, end_y)\n")
Result("orange line set at: \t(700, 10, 500, 200);\n")
Result("orange line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
solid_Line_white.ComponentGetRect( l_top, l_left, l_buttom, l_right )
Result("white line set at: \t(500, 10, 700, 200); \n")
Result("white line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
Result("using: ComponentGetBoundingRectangle();\t actual convention: (top, left, bottom, right)\n")
solid_Line_orange.ComponentGetBoundingRect( l_top, l_left, l_buttom, l_right );
Result("orange line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
solid_Line_white.ComponentGetBoundingRect( l_top, l_left, l_buttom, l_right );
Result("white line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
Result("using: ComponentGetBoundingRectInView();\t actual convention: (top, left, bottom, right)\n")
solid_Line_orange.ComponentGetBoundingRectInView( l_top, l_left, l_buttom, l_right );
Result("orange line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
solid_Line_white.ComponentGetBoundingRectInView( l_top, l_left, l_buttom, l_right );
Result("white line found at: \t(" + l_top + ", " + l_left + ", " + l_buttom + ", " + l_right + ")\n")
This solves the problem for me. Hope this helps somebody else as well. And maybe a better description in the manual could help as well.

Answer 2

This is an interestings question!
I think the behavior of ComponentGetRect() is doing correct thing but mislabeling the variables names in the documentation. While it says that it returns you a rectangle as top-left to bottom-right coordinates, it actually returns you the Y/X start coordinate and the Y/X end coordiante pair of the Annotation. (For other types of annoations, this then is [TLBR] ). Note that it is Y/X not X/Y! This is confusing, but to keep it in line with the more general "component" object.
Similarly, the signature variables names for NewLineAnnotation() are wrong, as they are obvisoulsy giving a start to end direction, as you can easily try out when using arrow-annotations instead. (See example script below.)
You can defenitly set the direction of a created line or arrow annotation using:
Component NewLineAnnotation( Number StartY, Number StartX, Number EndY, Number EndX )
Component NewArrowAnnotation( Number StartY, Number StartX, Number EndY, Number EndX )
Similarly, you should use for reading the postions:
ComponentGetRect( NumberVariable StartY, NumberVariable StartX, NumberVariable EndY, NumberVariable EndX )
Now, and alternative way of getting start and end coordinates would be the control point of the component, and the F1 help documention explicitly lists the control point ID values:
So, the presumably correct way would be to ask the componet of the coordinates of the specified control point using:
Boolean ComponentGetControlPoint( Component comp, Number loc, NumberVariable x, NumberVariable y )
However, giving this a test (see script below) it does not actually work for the control point ID values 1 and 2. It seems that the two control points for start/end of a line have not been implemented with the command.
But, you can use the "Top/Left" control point 4 for getting the start value and the "Bottom/Right" control point 7 for getting the end value. Again, this just matches the same somewhat irregular mapping of "line/arrow" annotations on the regular components.
Alternatvive way of getting a start point XY:
Boolean ComponentGetControlPoint( Component comp, 4, NumberVariable x, NumberVariable y )
Alternatvive way of getting a end point XY:
Boolean ComponentGetControlPoint( Component comp, 7, NumberVariable x, NumberVariable y )
Test script used
// Control Point constants. See F1 help documentaton ("Component Object" Overview)
number kLineStart = 1 // = start point of line
number kLineEnd = 2 // = end point of line
number kTopLeft = 4 // = top-left for rect, or start point for line
number kBottomRight = 7 // = bottom-right for rect, or end point for line
number sx = 50
number sy = 30
number ex = 400
number ey = 200
number sizeX = 500
number sizeY = 500
void PrintAnnoInfo( component anno )
{
if ( !anno.ComponentIsValid() ) return
number t,l,b,r
anno.ComponentGetRect( t, l, b, r )
// note that it is return StartY, StartX, EndY, EndX into TLBR!
number type = anno.ComponentGetType()
Result( "\n\n Component of type " + type + ":" )
Result( "\n\t Position rect: " + t + " / " + l + " / "+ b + " / "+ r )
Result( "\n\t\t { TOP / LEFT / BOTTOM / RIGHT }" )
number sx, sy, ex, ey
if ( !anno.ComponentGetControlPoint( kLineStart, sx, sy ) )
Result( "\n INVALID Control point for annotation type. ( " + kLineStart + " ) " )
else
Result( "\n\t Start point (X/Y): " + sx + " / " + sy )
if ( !anno.ComponentGetControlPoint( kLineEnd, ex, ey ) )
Result( "\n INVALID Control point for annotation type. ( " + kLineEnd + " ) " )
else
Result( "\n\t End point (X/Y) : " + ex + " / " + ey )
if ( !anno.ComponentGetControlPoint( kTopLeft, sx, sy ) )
Result( "\n INVALID Control point for annotation type. ( " + kLineStart + " ) " )
else
Result( "\n\t Start point (X/Y): " + sx + " / " + sy )
if ( !anno.ComponentGetControlPoint( kBottomRight, ex, ey ) )
Result( "\n INVALID Control point for annotation type. ( " + kLineEnd + " ) " )
else
Result( "\n\t End point (X/Y) : " + ex + " / " + ey )
Result( "\n\n" )
}
// clear workspace and created dummy
EGUPerformActionWithAllShownImages( "Delete" )
ClearResults()
Result( "Component direction test:\n\n" )
image img := Realimage( "Test", 4, sizeX, sizeY )
img.ShowImage()
imageDisplay disp = img.ImageGetImageDisplay(0)
// Creating and adding line-Annotation
number UseArrow
useArrow = TwoButtonDialog( "In this test use", "Arrows", "Lines" )
string msg
msg = "\nAdding " + (useArrow?"arrow":"line") + ":"
msg += "\n from (" + sx + " / " + sy + ") to (" + ex + " / " + ey + ")"
msg += "\n { from (Ex/Ey) to (Sx/Sy) }"
Result( msg )
OKdialog( msg )
Component anno
if ( useArrow )
anno = NewArrowAnnotation( sy, sx, ey, ex ) // note that it is YX!
else
anno = NewLineAnnotation( sy, sx, ey, ex ) // note that it is YX!
anno.ComponentSetForegroundcolor(1,0,0)
disp.ComponentAddChildAtEnd( anno )
anno.PrintAnnoInfo()
msg = "\nAdding " + (useArrow?"arrow":"line") + ":"
msg += "\n from (" + ex + " / " + ey + ") to (" + sx + " / " + sy + ")"
msg += "\n { from (Ex/Ey) to (Sx/Sy) }"
Result( msg )
OKdialog( msg )
if ( useArrow )
anno = NewArrowAnnotation( ey, ex, sy, sx ) // note that it is YX!
else
anno = NewLineAnnotation( ey, ex, sy, sx ) // note that it is YX!
anno.ComponentSetForegroundcolor(0,1,0)
disp.ComponentAddChildAtBeginning( anno )
anno.PrintAnnoInfo()