Canvas2D - How do I send texture coordinate to the shaders?

[Knight]

I want to draw a texture on the line that user draws on the screen. Like a mouse trail, so I follow this tutorial. . The only thing that doesn't answer me is sending the custom uv to the shaders. I vaguely remember that in C++, I can create struct or something and the shader will know how to handle it. It seems that is not the case here. I can't even figure out how does "index" property in vertex shader gets there. Even so, I can't use the "index" approach as the line won't be full rectangle as in the example.

Right now, I copied & pasted the entire lines2d classes and try to customize to be able to draw texture on there, but I don't know how to send the custom uv that I've calculated to the shader. Anyone can explain that to me? Or am I looking at this a wrong way?

[GameMonetize]

Do you mind sharing a PG to repro what you are doing?

Perhaps have a look to this one as well: http://doc.babylonjs.com/overviews/gui

[Knight]

14 hours ago, Deltakosh said:

Do you mind sharing a PG to repro what you are doing?

Perhaps have a look to this one as well: http://doc.babylonjs.com/overviews/gui

http://playground.babylonjs.com/#9AHTEG

I want to draw the texture on the line at the bottom left, and make it curve along with the line too.

GUI is nice, and I may change to it in the future, but that still doesn't give me what I want. And from what I see, I won't have access to shaders that way too

Aside from adding extra variable (_texture and _fillUV), I haven't changed any process from lines2d at all

[Wingnut]

Hi again.  This is over my head, but... might need to hack the Lines2D shader code... https://github.com/BabylonJS/Extensions/tree/master/canvas2D/src/shaders

Not sure how to add texture feature to the lines2d shader.  But heck, let's ask @NasimiAsl if he has comments.  He is a GPU GOD! 

[NasimiAsl]

varying vec4 vColor;
	void main(void) {
	gl_FragColor = vColor;
	}

 

with this? i think that need have some customizable function for access to control shader after that i can help

varying vec4 vColor; uniform sampler2D txt1; uniform vec2 screen;
	void main(void) { vec3 txt = texture2D(txt1, vec2(gl_FragCoord.x/screen.x ,gl_FragCoord.y / screen.y ).rgb;
	gl_FragColor = vColor*0.5 +0.5 * vec4(txt,1.);
	}

 

 

[Knight]

8 hours ago, NasimiAsl said:

varying vec4 vColor;
	void main(void) {
	gl_FragColor = vColor;
	}

 

with this? i think that need have some customizable function for access to control shader after that i can help

varying vec4 vColor; uniform sampler2D txt1; uniform vec2 screen;
	void main(void) { vec3 txt = texture2D(txt1, vec2(gl_FragCoord.x/screen.x ,gl_FragCoord.y / screen.y ).rgb;
	gl_FragColor = vColor*0.5 +0.5 * vec4(txt,1.);
	}

 

 

I have not gone to fragment shader part yet, because I am now figuring out how to sent the uv to the vertex shader. In the PG, I use the lines2d shaders because I don't know how to upload my slightly edited version of it and use in PG.