use glsl::syntax::ShaderStage;
use glsl_quasiquote::glsl;

use super::CodePiece;
use glsl::syntax::TranslationUnit;
use glsl::transpiler::glsl::show_translation_unit;

use crate::impl_code_piece;

pub struct Constants {
    pub raw: ShaderStage,
}

impl Constants {
    pub fn new() -> Constants {
        let raw = glsl! {

            #ifndef _GLUMPY__CONSTANTS__
            #define _GLUMPY__CONSTANTS__

            // The base of natural logarithms (e)
            const float M_E = 2.71828182845904523536028747135266250;

            // The logarithm to base 2 of M_E (log2(e))
            const float M_LOG2E = 1.44269504088896340735992468100189214;

            // The logarithm to base 10 of M_E (log10(e))
            const float M_LOG10E = 0.434294481903251827651128918916605082;

            // The natural logarithm of 2 (loge(2))
            const float M_LN2 = 0.693147180559945309417232121458176568;

            // The natural logarithm of 10 (loge(10))
            const float M_LN10 = 2.30258509299404568401799145468436421;

            // Pi, the ratio of a circle's circumference to its diameter.
            const float M_PI = 3.14159265358979323846264338327950288;

            // Pi divided by two (pi/2)
            const float M_PI_2 = 1.57079632679489661923132169163975144;

            // Pi divided by four  (pi/4)
            const float M_PI_4 = 0.785398163397448309615660845819875721;

            // The reciprocal of pi (1/pi)
            const float M_1_PI = 0.318309886183790671537767526745028724;

            // Two times the reciprocal of pi (2/pi)
            const float M_2_PI = 0.636619772367581343075535053490057448;

            // Two times the reciprocal of the square root of pi (2/sqrt(pi))
            const float M_2_SQRTPI = 1.12837916709551257389615890312154517;

            // The square root of two (sqrt(2))
            const float M_SQRT2 = 1.41421356237309504880168872420969808;

            // The reciprocal of the square root of two (1/sqrt(2))
            const float M_SQRT1_2 = 0.707106781186547524400844362104849039;

            // 1 degree in radians
            const float degree = 180.0/M_PI;

            // 1 radian in degrees
            const float radian = M_PI/180.0;

            #endif
        };

        Constants { raw }
    }
}

impl_code_piece!(Constants, raw);