Writing Shaders

pygame_shaders provides support for the integartion of GLSL vertex, fragment and compute shaders into pygame projects. Typically GLSL shaders will end in the extenison .glsl In the case of pygame_shaders, the typical starting point of your shaders will look like this:

vertex.glsl:

#version 330 core //version

/*
pygame_shaders provides a vec3 which repesents the current vertex positon and a vec2
representing the current texture coordinate on layout location 0 and 1 respectively.
*/
layout (location = 0) in vec3 vertexPos;
layout (location = 1) in vec2 vertexTexCoord;

// the vertex shader outputs a fragment texture coordinate.
out vec2 fragmentTexCoord;

//add your own variables here.

void main()
{
    fragmentTexCoord = vertexTexCoord; //set the fragment tex coord to the texture coordinate
    gl_Position = vec4(vertexPos, 1.0); //position the vertex at the vertex position.
}

fragment.glsl:

#version 330 core //version

in vec3 fragmentColor; // The color of the current coordinate/
in vec2 fragmentTexCoord; // The texture coordinate which we will use in the sampler2D lookup.

out vec4 color; // The color we are outputting.

uniform sampler2D imageTexture; // The texture which the shader is provided.

void main() {
    color = texture(imageTexture, fragmentTexCoord); //Peform the above desribed lookup and output it to the color.
}

While the names of library provided variables are up to you to decide. pygame_shaders provides a DEFAULT_VERTEX_SHADER and DEFAULT_FRAGMENT_SHADER, if one of these default shaders is in use, you will have to adhere to the above naming.

A default compute shader is slightly more flexible:

compute.glsl:

#version 460 core //compute shaders always need version 46o over above
layout(local_size_x = 8, local_size_y = 4, local_size_z = 1) in; // The number of threads you want to invoke. (Can be changed to suit the needs of your computations)

layout(rgba32f, binding = 0) uniform image2D screen; // Typically a compute shader will take in an image via a binding as input (once again, not required can be modified based on your needs)

void main() {
    // Whatever you like :D
}