Alex Stahl

Does jit.gl.sketch incorporate a message to set the OpenGL polygon stippling pattern? Line stippling works fine, and apparently polygon_stipple can be enabled and disabled, but I don't see a message to set the 32x32 pattern matrix.

polygon-stippling

On Mar 6, 2007, at 9:51 AM, Alex Stahl wrote:

> Does jit.gl.sketch incorporate a message to set the OpenGL polygon 

> stippling pattern? Line stippling works fine, and apparently 

> polygon_stipple can be enabled and disabled, but I don't see a 

> message to set the 32x32 pattern matrix.

Unfortunately, we don't support a polygon stippling matrix at the 

moment (and it probably won't make it into 1.6.3). You might be to 

just bind a texture and use one of the various auto texturing modes. 

Not sure if there's some functional problem with that for your 

application, but it would seem that with some appropriate 

interpolation (none), blending (on), texture generation (eyespace), 

and an appropriate scaling factor to match the pixels on the screen 

that it should work similar to the standard polygon stippling setting.

> Does jit.gl.sketch incorporate a message to set the OpenGL polygon  
> stippling pattern? Line stippling works fine, and apparently  
> polygon_stipple can be enabled and disabled, but I don't see a  
> message to set the 32x32 pattern matrix.

Unfortunately, we don't support a polygon stippling matrix at the  
moment (and it probably won't make it into 1.6.3). You might be to  
just bind a texture and use one of the various auto texturing modes.  
Not sure if there's some functional problem with that for your  
application, but it would seem that with some appropriate  
interpolation (none), blending (on), texture generation (eyespace),  
and an appropriate scaling factor to match the pixels on the screen  
that it should work similar to the standard polygon stippling setting.

Thanks very much for the speedy reply, I'll try that approach. -Alex

Actually you can do polygon stippling with jit.gl.lua. Here's a patch

that takes a video and uses it to create a stippling pattern.

stippleMat = jit.matrix(1, "char", 32, 32)

        pattern[j][i] = i*j/(32*32)*255

        pattern[i] = stippleMat[i]

Actually you can do polygon stippling with jit.gl.lua.  Here's a patch
that takes a video and uses it to create a stippling pattern.

for j=1, 32 do
	pattern[j] = {}
	for i=1, 32 do
		pattern[j][i] = i*j/(32*32)*255
	end
end

function jit_matrix(name)
	stippleMat:frommatrix(name)

	for i=1, 32 do
		pattern[i] = stippleMat[i]
	end	
end

function draw()
	gl.Color(1.0, 0.0, 0.0)
	gl.Enable("POLYGON_STIPPLE")
	gl.PolygonStipple(pattern)

	gl.Begin("POLYGON")
		gl.Vertex(-2.0, 5.0)
		gl.Vertex(2.0, 5.0)
		gl.Vertex(5.0, 2.0)
		gl.Vertex(5.0, -2.0)
		gl.Vertex(2.0, -5.0)
		gl.Vertex(-2.0, -5.0)
		gl.Vertex(-5.0, -2.0)
		gl.Vertex(-5.0, 2.0)
	gl.End()
 end


You can do the same thing as ploygon stippling with jit.gl.texture

@colormode lumalpha @dim 32 32 @rectangle 0 @wrap repeat. Plus you'll

BTW,
You can do the same thing as ploygon stippling with jit.gl.texture
@colormode lumalpha @dim 32 32 @rectangle 0 @wrap repeat.  Plus you'll
have more flexibility.