Codea as shader editor

Shaders
1

I’d like to know is it possible to use codea as shader editor?

2

Dave, Thanks for your answer, yeah I’m looking for a something similar to this (https://www.shadertoy.com/new). according to your answer. looks like codea will be suitable for my need. because currntly I’m learning shaders. and i want to write it line by line but thre is no cool shader editors for ios.

3

@noName Here’s a simple shader that’s similar to what shows in the link above. This one doesn’t vary the color over time, but that could be easily added.

displayMode(FULLSCREEN)

function setup()
    m=mesh()
    m:addRect(WIDTH/2,HEIGHT/2,WIDTH,HEIGHT)
    m.shader=shader(Shader.vert,Shader.frag)
end

function draw() 
    background(0) 
    m:draw()
end

Shader = 
    {   vert=
        [[
        uniform mat4 modelViewProjection;
        varying highp vec2 vTexCoord;
        attribute vec2 texCoord;
        attribute vec4 position; 
        void main() 
        {   gl_Position = modelViewProjection * position;
            vTexCoord=texCoord;
        }  
        ]],
   
        frag=
        [[
        highp float r=0.;
        highp float g=0.;
        highp float b=0.;
        varying highp vec2 vTexCoord;
        void main() 
        {   r=vTexCoord.x;
            g=(vTexCoord.x*vTexCoord.y);
            b=vTexCoord.y;
            gl_FragColor = vec4(r,g,b,1.); 
        }    
        ]]  
    }
4

Here’s a shader with varying color.


displayMode(FULLSCREEN)

function setup()
    m=mesh()
    m:addRect(WIDTH/2,HEIGHT/2,WIDTH,HEIGHT)
    m.shader=shader(Shader.vert,Shader.frag)
end

function draw() 
    background(0) 
    m.shader.tm=os.clock()
    m:draw()
end

Shader = 
    {   vert = 
        [[
        uniform mat4 modelViewProjection;
        varying highp vec2 vTexCoord;
        attribute vec2 texCoord;
        attribute vec4 position; 
        void main() 
        {   gl_Position = modelViewProjection * position;
            vTexCoord=texCoord;
        }   
        ]],
   
        frag = 
        [[
        uniform highp float tm;
        varying highp vec2 vTexCoord;
        void main() 
        {   highp float x=vTexCoord.x;
            highp float y=vTexCoord.y;
            gl_FragColor = vec4(sin(tm)-cos(tm),x*y+cos(tm),x*y+sin(tm),1.); 
        }    
        ]]
    }
5

What do you mean by a shader editor. You can create/edit/change/run a shader, but if you’re not familiar with the language or syntax then you might have trouble getting it to run. Codea isn’t like some of the other programs where you don’t need to know anything. Where you just change some parameters and a shader runs. With Codea, you need to write every line of code from scratch or from another shader example. There isn’t an easy way, but once you learn Codea and the shader language it gets easier. Once you know what you’re doing, you can probably write any shader to do anything you want. There’s some shader examples with Codea and there’s more examples in the forum. If you have more questions, just ask. Welcome to the forum.