Shader - Potassium

This object is new and subject to change; keep up with the documentation in case of changes.

Property	Type	Default
Vertex	`string`	""
Pixel	`string`	""
Position	`Vector2`	Vector2.zero
Size	`Vector2`	Vector2.zero

Method	Description
`Create(): ()`	Builds the shader from `Vertex` and `Pixel`.

Things to keep in mind

Create must be called every time after you change the Vertex and Pixel shaders.
The entry points for the Vertex and Pixel shaders are called “main”, you cannot change this.
If Size is not set, the shader will take up the maximum available space of the game window.

Tips

To access the extra globals that Potassium gives to the GPU, define them as follows in your Pixel shader:

cbuffer Params : register(b0)
{
    float time;
    float2 resolution;
    float2 mouse;
};

Wavey Sine Shader Example

local shaderObject = Drawing.new("Shader")

shaderObject.Vertex = [[
struct VSOut
{
    float4 pos : SV_POSITION;
    float2 uv  : TEXCOORD0;
};

VSOut main(uint id : SV_VertexID)
{
    VSOut o;

    float2 pos[3] = {
        float2(-1.0, -1.0),
        float2(-1.0,  3.0),
        float2( 3.0, -1.0)
    };

    float2 uv[3] = {
        float2(0.0, 1.0),
        float2(0.0, -1.0),
        float2(2.0, 1.0)
    };

    o.pos = float4(pos[id], 0.0, 1.0);
    o.uv  = uv[id];

    return o;
}]]

shaderObject.Pixel = [[
cbuffer Params : register(b0)
{
    float time;
	float2 resolution;
    float2 mouse;
};

float4 main(float4 pos : SV_Position, float2 uv : TEXCOORD0) : SV_Target
{
    float2 p = uv - 0.5;
    p *= 2.0;

    for (int i = 1; i < 5; i++)
    {
        float fi = (float)(i + 11);

        float2 freq  = float2(1.6, 1.1) * fi;
        float2 phase = time * (float)i * float2(3.4, 0.5) / 10.0;

        p += sin(p.yx * freq + phase) * 0.1;
    }

    float c = abs(sin(p.y) + sin(p.x)) * 0.5;

    return float4(c.xxx, 1.0);
}]]

shaderObject:Create()