/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2020                                                               *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
 *                                                                                       *
 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
 *                                                                                       *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#version 460  core

; // preprocessor add semicolon to isolate error messages
#line 1 1 // C:\os\clean\OpenSpace-0.16.0\shaders\floatoperations.glsl
/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2020                                                               *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
 *                                                                                       *
 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
 *                                                                                       *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#ifndef _FLOATOPERATIONS_GLSL_
#define _FLOATOPERATIONS_GLSL_

/**
 * Convert a positive floating point distance [0, 10^27]
 * (size of observable universe)
 * to a float in the range [-1, 1], suitable for depth buffer storage.
 * Note: This needs to be a monotonic function, so that the value can
 * still be used for depth comparison.
 */
float normalizeFloat(float inpt) {
    if (inpt > 1.0) {
        return inpt / pow(10, 30);
    } else {
        return inpt - 1.0;
    }
}

float denormalizeFloat(float inpt) {
    if (inpt < 0.0) {
        return inpt + 1.0;
    } else {
        return inpt * pow(10, 30);
    }
}

/**
 * Compute the length of a vector.
 * Supporting huge vectors, where the square of any of the components is too large to be
 * represented as a float.
 */
float safeLength(vec4 v) {
    float m = max(max(max(abs(v.x), abs(v.y)), abs(v.z)), abs(v.w));
    if (m > 0.f) {
        return length(v / m) * m;
    } else {
        return 0.f;
    }
}

float safeLength(vec3 v) {
    float m = max(max(abs(v.x), abs(v.y)), abs(v.z));
    if (m > 0.f) {
        return length(v / m) * m;
    } else {
        return 0.f;
    }
}

float safeLength(vec2 v) {
    float m = max(abs(v.x), abs(v.y));
    if (m > 0.f) {
        return length(v / m) * m;
    } else {
        return 0.f;
    }
}

/**
 * Normalize a vector
 * Supporting huge vectors, where the square of any of the components is too large to be
 * represent as a float.
 */
vec3 safeNormalize(vec3 v) {
    float m = max(max(abs(v.x), abs(v.y)), abs(v.z));
    return normalize(v / m);
}

#endif // _FLOATOPERATIONS_GLSL_
; // preprocessor add semicolon to isolate error messages
#line 28 0 // C:\os\clean\OpenSpace-0.16.0\modules\galaxy\shaders\billboard_ge.glsl
; // preprocessor add semicolon to isolate error messages
#line 1 2 // C:\os\clean\OpenSpace-0.16.0\shaders\PowerScaling\powerScalingMath.hglsl
/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2020                                                               *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
 *                                                                                       *
 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
 *                                                                                       *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#ifndef POWERSCALING_MATH_HGLSL
#define POWERSCALING_MATH_HGLSL


const float k = 10.0;
const float FLT_MAX = 1e38; // Not max but large enough for the purpose

float log10(float x) {
    return log(x) / log(10.0);
}

vec4 psc_normalization(vec4 v) {
    vec4 v2 = v;
    float l = length(v.xyz);
    v2.xyz = v.xyz / l;
    v2.w = v.w - log10(1.0/l);
    return v2;
}

vec4 psc_addition(vec4 v1, vec4 v2) {
    float ds = v2.w - v1.w;
    if(ds >= 0) {
        float p = pow(k,-ds);
        return vec4(v1.x*p + v2.x, v1.y*p + v2.y, v1.z*p + v2.z, v2.w);
    } else {
        float p = pow(k,ds);
        return vec4(v1.x + v2.x*p, v1.y + v2.y*p, v1.z + v2.z*p, v1.w);
    }
}

vec4 psc_subtraction(vec4 v1, vec4 v2) {
    vec4 negV2 = vec4(-v2.xyz, v2.w);
    return psc_addition(v1, negV2);
}

vec2 psc_addition(vec2 v1, vec2 v2) {
    float ds = v2.y - v1.y;
    if(ds >= 0) {
        float p = pow(k,-ds);
        return vec2(v1.x*p + v2.x, v2.y);
    } else {
        float p = pow(k,ds);
        return vec2(v1.x + v2.x*p, v1.y);
    }
}

vec2 psc_subtraction(vec2 v1, vec2 v2) {
    vec2 negV2 = vec2(-v2.x, v2.y);
    return psc_addition(v1, negV2);
}


vec4 z_normalization(vec4 v_in) {
    vec4 v_out = v_in;
    v_out.z = 0;
    //if ( v_out.z < -v_out.w )
    //  v_out.z = -v_out.w;
    //else if (v_out.z > v_out.w)
    //  v_out.z = v_out.w;
    return v_out;
}

/**
 * Convert a psc vector to a float
 */
vec3 pscToLinear(vec4 position) {
    return pow(k, position.w) * position.xyz;
}

/**
 * Convert a psc scalar to a float
 */
float pscToLinear(vec2 position) {
    return pow(k, position.y) * position.x;
}

#endif
; // preprocessor add semicolon to isolate error messages
#line 29 0 // C:\os\clean\OpenSpace-0.16.0\modules\galaxy\shaders\billboard_ge.glsl

uniform dvec3 eyePosition;
uniform dvec3 cameraUp;
uniform dmat4 cameraViewProjectionMatrix;
uniform dmat4 modelMatrix;

layout(points) in;
layout(triangle_strip, max_vertices = 4) out;

in vec4 vs_gPosition[];
in vec3 vs_color[];

out vec4 vs_position;
out vec2 psfCoords;
flat out vec3 ge_color;
flat out float ge_screenSpaceDepth;

const double PARSEC = 3.08567756E16;

void main() {
    vs_position = gl_in[0].gl_Position; // in object space
    ge_color = vs_color[0];

    double scaleMultiply = 8.0;

    dvec4 dpos = dvec4(vs_position);
    dpos.xyz *= scaleMultiply;
    dpos = modelMatrix * dpos;
    dpos /= PARSEC;
    //It lies about 8 kpc from the center on what is known as the Orion Arm of the Milky Way
    dpos.x += 8000;

    scaleMultiply *= 4.0;
    dvec3 scaledRight    = dvec3(0.0);
    dvec3 scaledUp       = dvec3(0.0);
    vec4 bottomLeftVertex, bottomRightVertex, topLeftVertex, topRightVertex;

    dvec3 normal   = normalize(eyePosition - dpos.xyz);
    dvec3 newRight = normalize(cross(cameraUp, normal));
    dvec3 newUp    = cross(normal, newRight);
    scaledRight    = scaleMultiply * newRight;
    scaledUp       = scaleMultiply * newUp;

    bottomLeftVertex = z_normalization(vec4(cameraViewProjectionMatrix *
                        dvec4(dpos.xyz - scaledRight - scaledUp, dpos.w)));

    //dvec4 dposCamera = cameraViewProjectionMatrix * dpos;
    //ge_screenSpaceDepth = float(length(eyePosition - dposCamera.xyz)/PARSEC);
    ge_screenSpaceDepth  = bottomLeftVertex.w;

    topRightVertex = z_normalization(vec4(cameraViewProjectionMatrix *
                            dvec4(dpos.xyz + scaledUp + scaledRight, dpos.w)));

    bottomRightVertex = z_normalization(vec4(cameraViewProjectionMatrix *
                    dvec4(dpos.xyz + scaledRight - scaledUp, dpos.w)));
    topLeftVertex = z_normalization(vec4(cameraViewProjectionMatrix *
                        dvec4(dpos.xyz + scaledUp - scaledRight, dpos.w)));

    // Build primitive
    gl_Position = topLeftVertex;
    psfCoords   = vec2(-1.0, 1.0);
    EmitVertex();
    gl_Position = bottomLeftVertex;
    psfCoords   = vec2(-1.0, -1.0);
    EmitVertex();
    gl_Position = topRightVertex;
    psfCoords   = vec2(1.0, 1.0);
    EmitVertex();
    gl_Position = bottomRightVertex;
    psfCoords   = vec2(1.0, -1.0);
    EmitVertex();
    EndPrimitive();
}
