use super::CodePiece;
use glsl::parser::Parse;
use glsl::syntax::ShaderStage;
use glsl::syntax::TranslationUnit;
use glsl::transpiler::glsl::show_translation_unit;

use crate::impl_code_piece;

pub struct Trackball(pub ShaderStage);

impl Trackball {
    pub fn new() -> Self {
        let raw = {
            "
            uniform mat4 trackball_view;
            uniform mat4 trackball_model;
            uniform mat4 trackball_projection;

            vec4 transform(vec4 position)
            {
                return trackball_projection
                       * trackball_view
                       * trackball_model
                       * position;
            }

            vec4 position(float x)
            {
                return vec4(x, 0.0, 0.0, 1.0);
            }

            vec4 position(float x, float y)
            {
                return vec4(x, y, 0.0, 1.0);
            }

            vec4 position(vec2 xy)
            {
                return vec4(xy, 0.0, 1.0);
            }

            vec4 position(float x, float y, float z)
            {
                return vec4(x, y, z, 1.0);
            }

            vec4 position(vec3 xyz)
            {
                return vec4(xyz, 1.0);
            }

            vec4 position(vec4 xyzw)
            {
                return xyzw;
            }

            vec4 position(vec2 xy, float z)
            {
                return vec4(xy, z, 1.0);
            }

            vec4 position(float x, vec2 yz)
            {
                return vec4(x, yz, 1.0);
            }
        "
        };

        Self(ShaderStage::parse(raw).unwrap())
    }
}

impl_code_piece!(Trackball, 0);