What the Heck?

[The Artful Dodger]

Hello, all:

I was just doing a bit of programming and I noticed a problem that isn't making any sense. So, I created a new "instrument", with a bare minimum of code, so that it could be demonstrated. First, here is the code:

Code: Select all

PaneCanvas = canvas_add(0, 0, 25, 25)
BoxCanvas = canvas_add(5, 5, 15, 15)
--
	canvas_draw(PaneCanvas, function() 
		_rect(1, 1, 23, 23)
		_stroke("red", 2)
	end)
--
	canvas_draw(BoxCanvas, function()
		_rect(1, 1, 13, 13)
		_stroke("green", 1)
--
		_move_to(3, 4)
		_line_to(9, 4)
		_stroke("blue", 1)
	end)

Then, here is the result:

Line Test.png (271 Bytes) Viewed 631 times

You will note that the colour of the inner box is not "green" and the line is not "blue". Furthermore, the inner box is not "stroke = 1" nor is the line!

I do not understand - I have been doing this kind of thing for quite a while now but this is a first!

Sparky

[The Artful Dodger]

Well, I can't seem to get the image to show. Maybe I need some OJT!

image.png (133 Bytes) Viewed 631 times

[The Artful Dodger]

I give up. I cannot make an image appear. Sorry.

Sparky

[Ralph]

I have no idea what you see But it might be that it is blending.

[The Artful Dodger]

Hi, Ralph:
How do I add an image?

[Ralph]

Add it as a attachment to your message. You can do this below the text editor.

[The Artful Dodger]

What is blending? I'm trying to draw a straight line with _move_to and _line_to! the line I get is wider than I asked for and the color is faded.

[The Artful Dodger]

I'll try again.

Line Test.png (271 Bytes) Viewed 614 times

But it doesn't work! That's the third time I've tried!

[The Artful Dodger]

I guess it's too small - 25 pixels wide. I'll make it bigger!

[The Artful Dodger]

Here it is as 200x200.

Line Test.png (868 Bytes) Viewed 606 times

Her are the problems:
1. The green box is 2 pixels on top and to the left, instead of 1 as in the _stroke command.
2. The colour of the green box is not green, it is quite watered down.
3. The blue line is 2 pixels wide, not 1 as requested.
4. The colour of the blue line is not blue but a watered down blue.
Here's the new lua code:

Code: Select all

PaneCanvas = canvas_add(0, 0, 200, 200)
IALDCanvas = canvas_add(50, 50, 100, 100)
--
	canvas_draw(PaneCanvas, function() 
		_rect(1, 1, 198, 198)
		_stroke("red", 2)
	end)
--
	canvas_draw(IALDCanvas, function()
		_rect(1, 1, 99, 99)
		_stroke("green", 1)
--
		_move_to(10, 10)
		_line_to(25, 10)
		_stroke("blue", 1)
	end)

I don't understand what has happened.

Sparky