////  Environment.cpp//  interface////  Created by Andrzej Kapolka on 5/6/13.//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved. #include <QByteArray> #include <SharedUtil.h> #include "Camera.h"#include "Environment.h"#include "renderer/ProgramObject.h"#include "renderer/ShaderObject.h"#include "world.h" void Environment::init() {    switchToResourcesParentIfRequired();    _skyFromAtmosphereProgram = createSkyProgram("Atmosphere", _skyFromAtmosphereUniformLocations);    _skyFromSpaceProgram = createSkyProgram("Space", _skyFromSpaceUniformLocations);} void Environment::renderAtmosphere(Camera& camera) {        glMatrixMode(GL_MODELVIEW);    glPushMatrix();    glTranslatef(getAtmosphereCenter().x, getAtmosphereCenter().y, getAtmosphereCenter().z);     // use the camera distance to reset the near and far distances to keep the atmosphere in the frustum    glMatrixMode(GL_PROJECTION);    glPushMatrix();        float projection[16];    glGetFloatv(GL_PROJECTION_MATRIX, projection);    glm::vec3 relativeCameraPos = camera.getPosition() - getAtmosphereCenter();    float height = glm::length(relativeCameraPos);    float near = camera.getNearClip(), far = height + getAtmosphereOuterRadius();    projection[10] = (far + near) / (near - far);    projection[14] = (2.0f * far * near) / (near - far);    glLoadMatrixf(projection);        // use the appropriate shader depending on whether we're inside or outside    ProgramObject* program;    int* locations;    if (height < getAtmosphereOuterRadius()) {        program = _skyFromAtmosphereProgram;        locations = _skyFromAtmosphereUniformLocations;            } else {        program = _skyFromSpaceProgram;        locations = _skyFromSpaceUniformLocations;    }        // the constants here are from Sean O'Neil's GPU Gems entry    // (http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter16.html), GameEngine.cpp    program->bind();    program->setUniform(locations[CAMERA_POS_LOCATION], relativeCameraPos);    glm::vec3 lightDirection = glm::normalize(getSunLocation());    program->setUniform(locations[LIGHT_POS_LOCATION], lightDirection);    program->setUniform(locations[INV_WAVELENGTH_LOCATION],        1 / powf(getScatteringWavelengths().r, 4.0f),        1 / powf(getScatteringWavelengths().g, 4.0f),        1 / powf(getScatteringWavelengths().b, 4.0f));    program->setUniform(locations[CAMERA_HEIGHT2_LOCATION], height * height);    program->setUniform(locations[OUTER_RADIUS_LOCATION], getAtmosphereOuterRadius());    program->setUniform(locations[OUTER_RADIUS2_LOCATION], getAtmosphereOuterRadius() * getAtmosphereOuterRadius());    program->setUniform(locations[INNER_RADIUS_LOCATION], getAtmosphereInnerRadius());    program->setUniform(locations[KR_ESUN_LOCATION], getRayleighScattering() * getSunBrightness());    program->setUniform(locations[KM_ESUN_LOCATION], getMieScattering() * getSunBrightness());    program->setUniform(locations[KR_4PI_LOCATION], getRayleighScattering() * 4.0f * PIf);    program->setUniform(locations[KM_4PI_LOCATION], getMieScattering() * 4.0f * PIf);    program->setUniform(locations[SCALE_LOCATION], 1.0f / (getAtmosphereOuterRadius() - getAtmosphereInnerRadius()));    program->setUniform(locations[SCALE_DEPTH_LOCATION], 0.25f);    program->setUniform(locations[SCALE_OVER_SCALE_DEPTH_LOCATION],        (1.0f / (getAtmosphereOuterRadius() - getAtmosphereInnerRadius())) / 0.25f);    program->setUniform(locations[G_LOCATION], -0.990f);    program->setUniform(locations[G2_LOCATION], -0.990f * -0.990f);        glDepthMask(GL_FALSE);    glDisable(GL_DEPTH_TEST);    glutSolidSphere(getAtmosphereOuterRadius(), 100, 50);    glDepthMask(GL_TRUE);        program->release();        glPopMatrix();           glMatrixMode(GL_MODELVIEW);    glPopMatrix();   } ProgramObject* Environment::createSkyProgram(const char* from, int* locations) {    ProgramObject* program = new ProgramObject();    QByteArray prefix = QByteArray("resources/shaders/SkyFrom") + from;    program->attachFromSourceFile(GL_VERTEX_SHADER_ARB, prefix + ".vert");    program->attachFromSourceFile(GL_FRAGMENT_SHADER_ARB, prefix + ".frag");    program->link();        locations[CAMERA_POS_LOCATION] = program->getUniformLocation("v3CameraPos");    locations[LIGHT_POS_LOCATION] = program->getUniformLocation("v3LightPos");    locations[INV_WAVELENGTH_LOCATION] = program->getUniformLocation("v3InvWavelength");    locations[CAMERA_HEIGHT2_LOCATION] = program->getUniformLocation("fCameraHeight2");    locations[OUTER_RADIUS_LOCATION] = program->getUniformLocation("fOuterRadius");    locations[OUTER_RADIUS2_LOCATION] = program->getUniformLocation("fOuterRadius2");    locations[INNER_RADIUS_LOCATION] = program->getUniformLocation("fInnerRadius");    locations[KR_ESUN_LOCATION] = program->getUniformLocation("fKrESun");    locations[KM_ESUN_LOCATION] = program->getUniformLocation("fKmESun");    locations[KR_4PI_LOCATION] = program->getUniformLocation("fKr4PI");    locations[KM_4PI_LOCATION] = program->getUniformLocation("fKm4PI");    locations[SCALE_LOCATION] = program->getUniformLocation("fScale");    locations[SCALE_DEPTH_LOCATION] = program->getUniformLocation("fScaleDepth");    locations[SCALE_OVER_SCALE_DEPTH_LOCATION] = program->getUniformLocation("fScaleOverScaleDepth");    locations[G_LOCATION] = program->getUniformLocation("g");    locations[G2_LOCATION] = program->getUniformLocation("g2");        return program;}