piecewise.glsl

#version 310 es

// glslc -std=310es -fshader-stage=vertex piecewise.glsl
// spirv-opt -Os a.spv -o b.spv
// spirv-cross b.spv

layout(binding = 0) uniform FrameUniforms {
  mat4 clipFromWorldMatrix;
} frameUniforms;

layout(location = 0) in vec4 mesh_position;

void main() {
    mat4 mat = frameUniforms.clipFromWorldMatrix;
    mat4 rot;

    rot[0][0] = mat[0][0];
    rot[0][1] = mat[0][1];
    rot[0][2] = mat[0][2];
    rot[0][3] = mat[0][3];

    rot[1][0] = mat[1][0];
    rot[1][1] = mat[1][1];
    rot[1][2] = mat[1][2];
    rot[1][3] = mat[1][3];

    rot[2][0] = mat[2][0];
    rot[2][1] = mat[2][1];
    rot[2][2] = mat[2][2];
    rot[2][3] = mat[2][3];

    rot[3][0] = mat[3][0];
    rot[3][1] = mat[3][1];
    rot[3][2] = mat[3][2];
    rot[3][3] = mat[3][3];

    gl_Position = rot * mesh_position;
}