Small Feature Errors

[Keith Baxter]

Hi,

Sparky.
Are you telling us all that this code you posted in post #1 is now fixed by changing the graphics options in settings? I think that is an oversight on your part.

Code: Select all

PaneCanvas = canvas_add(0, 0, 200, 100)
BoxCanvas = canvas_add(15, 15, 150, 40)
--
	canvas_draw(PaneCanvas, function() 
		_rect(1, 1, 198, 98)
		_stroke("#FFD700", 2)
--
		_move_to(25, 60)
		_line_to(150, 60)
		_stroke("#FFD700", 1)
--
		_move_to(100, 50)
		_line_to(100, 90)
		_stroke("#FF0084", 1)
--
	end)
--
	canvas_draw(BoxCanvas, function()
		_rect(2, 2, 148, 23)
		_stroke("#008000", 1)
--
		_move_to(10, 10)
		_line_to(125, 10)
		_stroke("#9932CC", 1)
--
	end)
--

I suggest that you recheck your fixed code and compare to the code you first posted. It is impossible to have fixed the green box right side line stroke thickness. Reason being is that some of the green ("#008000") box draw parameters are outside of the canvas (BoxCanvas) parameters.

I press this point so that others should not get the impression, playing with the graphics settings will fix draws that fall outside the canvas parameters.

Keith

[jph]

Hi,

Sparky.
Are you telling us all that this code you posted in post #1 is now fixed by changing the graphics options in settings? I think that is an oversight on your part.

Code: Select all

PaneCanvas = canvas_add(0, 0, 200, 100)
BoxCanvas = canvas_add(15, 15, 150, 40)
--
	canvas_draw(PaneCanvas, function() 
		_rect(1, 1, 198, 98)
		_stroke("#FFD700", 2)
--
		_move_to(25, 60)
		_line_to(150, 60)
		_stroke("#FFD700", 1)
--
		_move_to(100, 50)
		_line_to(100, 90)
		_stroke("#FF0084", 1)
--
	end)
--
	canvas_draw(BoxCanvas, function()
		_rect(2, 2, 148, 23)
		_stroke("#008000", 1)
--
		_move_to(10, 10)
		_line_to(125, 10)
		_stroke("#9932CC", 1)
--
	end)
--

I suggest that you recheck your fixed code and compare to the code you first posted. It is impossible to have fixed the green box right side line stroke thickness. Reason being is that some of the green ("#008000") box draw parameters are outside of the canvas (BoxCanvas) parameters.

I press this point so that others should not get the impression, playing with the graphics settings will fix draws that fall outside the canvas parameters.

Keith

I am not sure where you are confused here Keith. But you cannot have 'half a pixel' or '0.5 pixel' is a physical item. It all depends on the DPI.
with a higher dpi you CAN have anti aliasing which uses the dpi intensity to give the impression. But not physically possibly to have a half (0.5) of a physical pixel.
Have a look at DPI and the way LCD screens work.
Joe

[Keith Baxter]

@jph

I am definitely not confused. Run this code which has a _stroke() of 0.5 pixels.
You will note that the Left, Top,and Bottom lines have a line_width of 0.5. The right line_width is 0.25 because half of the 0.5 line_width is outside of the canvas width parameter of 150.

So nothing to do with DPI or anything else. Simply that the OP original post talked of the right side of the green rectangle being half the size of the other three and that is because the _rect() width is to wide or the canvas width is to small.

Code: Select all

BoxCanvas = canvas_add(15, 15, 150, 40)
	canvas_draw(BoxCanvas, function()
		_rect(2, 2, 148, 23)
		_stroke("#008000", 0.5)
	end)

Lets take a look at two identical vertical strokes of 6 pixels. The center line is 6 pixels wide and the right line is 3 pixels. Reason is because the half the 6 pixels are outside the canvas parameter of 150

Code: Select all

Box2Canvas = canvas_add(15, 165, 150, 40)
	canvas_draw(Box2Canvas, function()
                _move_to(150,0)
                _line_to(150,40)
		_stroke("#008000", 6)
		
                _move_to(75,0)
                _line_to(75,40)
		_stroke("#008000", 6)				
	end)

Keith

EDIT: It might be that the API wording should be different. Because you can definitely draw a line 0.5 line_width.

[jph]

No worries Keith keep on believing. pixels are NOT lines
Joe

[Keith Baxter]

No worries Keith keep on believing. pixels are NOT lines
Joe

Joe.
This is drawn with canvas_draw() and line widths are from top down ( 0.1 , 0.25, 0.5, 0.75, 1, 1.5, 2, 8)
No matter how wide the line widths are the right side will ALWAYS be half because it falls outside the canvas width parameter.

ice_screenshot_20230116-130302.png (10.73 KiB) Viewed 693 times

Keith

[jph]

Hi Keith, nice,
Now research 'pixel' (not line width) -
Joe

[Keith Baxter]

Hi Keith, nice,
Now research 'pixel'
Joe

I know exactly what a pixel is. No need to research.

Keith

[jph]

Hi Keith, nice,
Now research 'pixel'
Joe

I know exactly what a pixel is. No need to research.

Keith

so, fine, what is 'half a pixel' ?

[Keith Baxter]

Hi Keith, nice,
Now research 'pixel'
Joe

I know exactly what a pixel is. No need to research.

Keith

so, fine, what is 'half a pixel' ?

Re-Read post #13. You might have missed my edit as you were posting as I was adding the edit.

[Corjan]

Hi,


Like Keith said, the fact that the right side of the rect isn't shown is completely logical because it is out of the canvas area.

When it comes to coordinations, things become messy.

Drawing a line from x=0,y=0 to x=0,y=100 doesn't necessarily mean that it will fill up the first row of pixels exactly.

You are asking it to draw a line of which center is exactly on the edge of the instrument (x=0), right between two pixels.
The anti aliasing code will try to center it anyways be interpolating with its neighboring pixels. That is why you get two pixels being drawn, and flushed out a bit.


Corjan