670 lines
21 KiB
C++
670 lines
21 KiB
C++
// renderglsl.cpp
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//
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// Functions for rendering objects using dynamically generated GLSL shaders.
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//
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// Copyright (C) 2006-2007, Chris Laurel <claurel@shatters.net>
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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#include <algorithm>
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#include <cstdio>
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#include <cstring>
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#include <cassert>
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#ifndef _WIN32
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#ifndef TARGET_OS_MAC
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#include <config.h>
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#endif
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#endif /* _WIN32 */
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#include <celutil/debug.h>
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#include <celmath/frustum.h>
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#include <celmath/distance.h>
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#include <celmath/intersect.h>
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#include <celutil/utf8.h>
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#include <celutil/util.h>
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#include "gl.h"
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#include "astro.h"
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#include "glext.h"
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#include "vecgl.h"
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#include "glshader.h"
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#include "shadermanager.h"
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#include "spheremesh.h"
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#include "lodspheremesh.h"
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#include "model.h"
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#include "regcombine.h"
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#include "vertexprog.h"
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#include "texmanager.h"
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#include "meshmanager.h"
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#include "render.h"
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#include "renderinfo.h"
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#include "renderglsl.h"
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using namespace std;
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const double AtmosphereExtinctionThreshold = 0.05;
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// Render a planet sphere with GLSL shaders
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void renderSphere_GLSL(const RenderInfo& ri,
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const LightingState& ls,
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RingSystem* rings,
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Atmosphere* atmosphere,
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float cloudTexOffset,
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float radius,
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unsigned int textureRes,
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int renderFlags,
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const Mat4f& planetMat,
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const Frustum& frustum,
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const GLContext& context)
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{
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Texture* textures[MAX_SPHERE_MESH_TEXTURES] =
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{ NULL, NULL, NULL, NULL, NULL, NULL };
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unsigned int nTextures = 0;
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glDisable(GL_LIGHTING);
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ShaderProperties shadprop;
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shadprop.nLights = min(ls.nLights, MaxShaderLights);
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// Set up the textures used by this object
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if (ri.baseTex != NULL)
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{
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shadprop.texUsage = ShaderProperties::DiffuseTexture;
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textures[nTextures++] = ri.baseTex;
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}
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if (ri.bumpTex != NULL)
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{
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shadprop.texUsage |= ShaderProperties::NormalTexture;
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textures[nTextures++] = ri.bumpTex;
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if (ri.bumpTex->getFormatOptions() & Texture::DXT5NormalMap)
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shadprop.texUsage |= ShaderProperties::CompressedNormalTexture;
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}
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if (ri.specularColor != Color::Black)
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{
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shadprop.lightModel = ShaderProperties::PerPixelSpecularModel;
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if (ri.glossTex == NULL)
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{
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shadprop.texUsage |= ShaderProperties::SpecularInDiffuseAlpha;
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}
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else
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{
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shadprop.texUsage |= ShaderProperties::SpecularTexture;
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textures[nTextures++] = ri.glossTex;
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}
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}
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else if (ri.lunarLambert != 0.0f)
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{
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// TODO: Lunar-Lambert model and specular color should not be mutually exclusive
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shadprop.lightModel = ShaderProperties::LunarLambertModel;
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}
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if (ri.nightTex != NULL)
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{
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shadprop.texUsage |= ShaderProperties::NightTexture;
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textures[nTextures++] = ri.nightTex;
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}
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if (ri.overlayTex != NULL)
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{
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shadprop.texUsage |= ShaderProperties::OverlayTexture;
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textures[nTextures++] = ri.overlayTex;
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}
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if (rings != NULL && (renderFlags & Renderer::ShowRingShadows) != 0)
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{
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Texture* ringsTex = rings->texture.find(textureRes);
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if (ringsTex != NULL)
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{
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glx::glActiveTextureARB(GL_TEXTURE0_ARB + nTextures);
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ringsTex->bind();
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nTextures++;
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// Tweak the texture--set clamp to border and a border color with
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// a zero alpha.
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float bc[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
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glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, bc);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
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GL_CLAMP_TO_BORDER_ARB);
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glx::glActiveTextureARB(GL_TEXTURE0_ARB);
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shadprop.texUsage |= ShaderProperties::RingShadowTexture;
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}
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}
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if (atmosphere != NULL)
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{
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if (renderFlags & Renderer::ShowAtmospheres)
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{
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// Only use new atmosphere code in OpenGL 2.0 path when new style parameters are defined.
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if (atmosphere->mieScaleHeight > 0.0f)
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shadprop.texUsage |= ShaderProperties::Scattering;
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}
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if ((renderFlags & Renderer::ShowCloudMaps) != 0 &&
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(renderFlags & Renderer::ShowCloudShadows) != 0)
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{
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Texture* cloudTex = NULL;
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if (atmosphere->cloudTexture.tex[textureRes] != InvalidResource)
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cloudTex = atmosphere->cloudTexture.find(textureRes);
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// The current implementation of cloud shadows is not compatible
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// with virtual or split textures.
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bool allowCloudShadows = true;
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for (unsigned int i = 0; i < nTextures; i++)
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{
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if (textures[i] != NULL &&
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(textures[i]->getLODCount() > 1 ||
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textures[i]->getUTileCount(0) > 1 ||
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textures[i]->getVTileCount(0) > 1))
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{
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allowCloudShadows = false;
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}
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}
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// Split cloud shadows can't cast shadows
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if (cloudTex != NULL)
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{
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if (cloudTex->getLODCount() > 1 ||
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cloudTex->getUTileCount(0) > 1 ||
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cloudTex->getVTileCount(0) > 1)
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{
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allowCloudShadows = false;
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}
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}
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if (cloudTex != NULL && allowCloudShadows)
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{
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shadprop.texUsage |= ShaderProperties::CloudShadowTexture;
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textures[nTextures++] = cloudTex;
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glx::glActiveTextureARB(GL_TEXTURE0_ARB + nTextures);
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cloudTex->bind();
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glx::glActiveTextureARB(GL_TEXTURE0_ARB);
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}
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}
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}
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// Set the shadow information.
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// Track the total number of shadows; if there are too many, we'll have
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// to fall back to multipass.
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unsigned int totalShadows = 0;
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for (unsigned int li = 0; li < ls.nLights; li++)
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{
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if (ls.shadows[li] && !ls.shadows[li]->empty())
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{
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unsigned int nShadows = (unsigned int) min((size_t) MaxShaderShadows, ls.shadows[li]->size());
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shadprop.setShadowCountForLight(li, nShadows);
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totalShadows += nShadows;
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}
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}
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// Get a shader for the current rendering configuration
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CelestiaGLProgram* prog = GetShaderManager().getShader(shadprop);
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if (prog == NULL)
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return;
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prog->use();
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#ifdef USE_HDR
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prog->setLightParameters(ls, ri.color, ri.specularColor, Color::Black, ri.nightLightScale);
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#else
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prog->setLightParameters(ls, ri.color, ri.specularColor, Color::Black);
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#endif
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prog->eyePosition = ls.eyePos_obj;
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prog->shininess = ri.specularPower;
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if (shadprop.lightModel == ShaderProperties::LunarLambertModel)
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prog->lunarLambert = ri.lunarLambert;
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if (shadprop.texUsage & ShaderProperties::RingShadowTexture)
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{
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float ringWidth = rings->outerRadius - rings->innerRadius;
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prog->ringRadius = rings->innerRadius / radius;
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prog->ringWidth = radius / ringWidth;
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}
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if (shadprop.texUsage & ShaderProperties::CloudShadowTexture)
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{
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prog->shadowTextureOffset = cloudTexOffset;
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prog->cloudHeight = 1.0f + atmosphere->cloudHeight / radius;
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}
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if (shadprop.hasScattering())
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{
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prog->setAtmosphereParameters(*atmosphere, radius, radius);
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}
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if (shadprop.shadowCounts != 0)
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prog->setEclipseShadowParameters(ls, radius, planetMat);
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glColor(ri.color);
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unsigned int attributes = LODSphereMesh::Normals;
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if (ri.bumpTex != NULL)
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attributes |= LODSphereMesh::Tangents;
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g_lodSphere->render(context,
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attributes,
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frustum, ri.pixWidth,
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textures[0], textures[1], textures[2], textures[3]);
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glx::glUseProgramObjectARB(0);
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}
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// Render a mesh object
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void renderModel_GLSL(Model* model,
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const RenderInfo& ri,
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ResourceHandle texOverride,
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const LightingState& ls,
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const Atmosphere* atmosphere,
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float radius,
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int renderFlags,
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const Mat4f& planetMat)
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{
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glDisable(GL_LIGHTING);
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GLSL_RenderContext rc(ls, radius, planetMat);
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if (renderFlags & Renderer::ShowAtmospheres)
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{
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rc.setAtmosphere(atmosphere);
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}
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rc.setPointScale(ri.pointScale);
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// Handle extended material attributes (per model only, not per submesh)
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rc.setLunarLambert(ri.lunarLambert);
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// Handle material override; a texture specified in an ssc file will
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// override all materials specified in the model file.
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if (texOverride != InvalidResource)
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{
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Mesh::Material m;
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m.diffuse = ri.color;
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m.specular = ri.specularColor;
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m.specularPower = ri.specularPower;
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m.maps[Mesh::DiffuseMap] = texOverride;
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rc.makeCurrent(m);
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rc.lock();
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}
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model->render(rc);
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glx::glUseProgramObjectARB(0);
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}
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// Render a mesh object unlit
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void renderModel_GLSL_Unlit(Model* model,
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const RenderInfo& ri,
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ResourceHandle texOverride,
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float radius,
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int renderFlags,
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const Mat4f& planetMat)
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{
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glDisable(GL_LIGHTING);
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GLSLUnlit_RenderContext rc(radius);
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rc.setPointScale(ri.pointScale);
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// Handle material override; a texture specified in an ssc file will
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// override all materials specified in the model file.
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if (texOverride != InvalidResource)
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{
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Mesh::Material m;
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m.diffuse = ri.color;
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m.specular = ri.specularColor;
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m.specularPower = ri.specularPower;
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m.maps[Mesh::DiffuseMap] = texOverride;
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rc.makeCurrent(m);
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rc.lock();
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}
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model->render(rc);
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glx::glUseProgramObjectARB(0);
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}
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// Render the cloud sphere for a world a cloud layer defined
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void renderClouds_GLSL(const RenderInfo& ri,
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const LightingState& ls,
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Atmosphere* atmosphere,
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Texture* cloudTex,
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Texture* cloudNormalMap,
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float texOffset,
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RingSystem* rings,
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float radius,
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unsigned int textureRes,
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int renderFlags,
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const Mat4f& planetMat,
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const Frustum& frustum,
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const GLContext& context)
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{
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Texture* textures[MAX_SPHERE_MESH_TEXTURES] =
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{ NULL, NULL, NULL, NULL, NULL, NULL };
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unsigned int nTextures = 0;
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glDisable(GL_LIGHTING);
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ShaderProperties shadprop;
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shadprop.nLights = ls.nLights;
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// Set up the textures used by this object
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if (cloudTex != NULL)
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{
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shadprop.texUsage = ShaderProperties::DiffuseTexture;
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textures[nTextures++] = cloudTex;
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}
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if (cloudNormalMap != NULL)
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{
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shadprop.texUsage |= ShaderProperties::NormalTexture;
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textures[nTextures++] = cloudNormalMap;
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if (cloudNormalMap->getFormatOptions() & Texture::DXT5NormalMap)
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shadprop.texUsage |= ShaderProperties::CompressedNormalTexture;
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}
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if (rings != NULL && (renderFlags & Renderer::ShowRingShadows) != 0)
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{
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Texture* ringsTex = rings->texture.find(textureRes);
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if (ringsTex != NULL)
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{
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glx::glActiveTextureARB(GL_TEXTURE0_ARB + nTextures);
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ringsTex->bind();
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nTextures++;
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// Tweak the texture--set clamp to border and a border color with
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// a zero alpha.
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float bc[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
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glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, bc);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
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GL_CLAMP_TO_BORDER_ARB);
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glx::glActiveTextureARB(GL_TEXTURE0_ARB);
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shadprop.texUsage |= ShaderProperties::RingShadowTexture;
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}
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}
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if (atmosphere != NULL)
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{
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if (renderFlags & Renderer::ShowAtmospheres)
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{
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// Only use new atmosphere code in OpenGL 2.0 path when new style parameters are defined.
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if (atmosphere->mieScaleHeight > 0.0f)
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shadprop.texUsage |= ShaderProperties::Scattering;
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}
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}
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// Set the shadow information.
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// Track the total number of shadows; if there are too many, we'll have
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// to fall back to multipass.
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unsigned int totalShadows = 0;
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for (unsigned int li = 0; li < ls.nLights; li++)
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{
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if (ls.shadows[li] && !ls.shadows[li]->empty())
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{
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unsigned int nShadows = (unsigned int) min((size_t) MaxShaderShadows, ls.shadows[li]->size());
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shadprop.setShadowCountForLight(li, nShadows);
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totalShadows += nShadows;
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}
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}
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// Get a shader for the current rendering configuration
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CelestiaGLProgram* prog = GetShaderManager().getShader(shadprop);
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if (prog == NULL)
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return;
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prog->use();
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prog->setLightParameters(ls, ri.color, ri.specularColor, Color::Black);
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prog->eyePosition = ls.eyePos_obj;
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prog->ambientColor = Vec3f(ri.ambientColor.red(), ri.ambientColor.green(),
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ri.ambientColor.blue());
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prog->textureOffset = texOffset;
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float cloudRadius = radius + atmosphere->cloudHeight;
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if (shadprop.hasScattering())
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{
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prog->setAtmosphereParameters(*atmosphere, radius, cloudRadius);
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}
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if (shadprop.texUsage & ShaderProperties::RingShadowTexture)
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{
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float ringWidth = rings->outerRadius - rings->innerRadius;
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prog->ringRadius = rings->innerRadius / cloudRadius;
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prog->ringWidth = 1.0f / (ringWidth / cloudRadius);
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}
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if (shadprop.shadowCounts != 0)
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prog->setEclipseShadowParameters(ls, cloudRadius, planetMat);
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unsigned int attributes = LODSphereMesh::Normals;
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if (cloudNormalMap != NULL)
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attributes |= LODSphereMesh::Tangents;
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g_lodSphere->render(context,
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attributes,
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frustum, ri.pixWidth,
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textures[0], textures[1], textures[2], textures[3]);
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prog->textureOffset = 0.0f;
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glx::glUseProgramObjectARB(0);
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}
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// Render the sky sphere for a world with an atmosphere
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void
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renderAtmosphere_GLSL(const RenderInfo& ri,
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const LightingState& ls,
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Atmosphere* atmosphere,
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float radius,
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const Mat4f& /*planetMat*/,
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const Frustum& frustum,
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const GLContext& context)
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{
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/*unsigned int nTextures = 0; Unused*/
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glDisable(GL_LIGHTING);
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ShaderProperties shadprop;
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shadprop.nLights = ls.nLights;
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shadprop.texUsage |= ShaderProperties::Scattering;
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shadprop.lightModel = ShaderProperties::AtmosphereModel;
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// Get a shader for the current rendering configuration
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CelestiaGLProgram* prog = GetShaderManager().getShader(shadprop);
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if (prog == NULL)
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return;
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prog->use();
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prog->setLightParameters(ls, ri.color, ri.specularColor, Color::Black);
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prog->ambientColor = Vec3f(0.0f, 0.0f, 0.0f);
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float atmosphereRadius = radius + -atmosphere->mieScaleHeight * (float) log(AtmosphereExtinctionThreshold);
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float atmScale = atmosphereRadius / radius;
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prog->eyePosition = Point3f(ls.eyePos_obj.x / atmScale, ls.eyePos_obj.y / atmScale, ls.eyePos_obj.z / atmScale);
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prog->setAtmosphereParameters(*atmosphere, radius, atmosphereRadius);
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#if 0
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// Currently eclipse shadows are ignored when rendering atmospheres
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if (shadprop.shadowCounts != 0)
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prog->setEclipseShadowParameters(ls, radius, planetMat);
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#endif
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glPushMatrix();
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glScalef(atmScale, atmScale, atmScale);
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glFrontFace(GL_CW);
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glEnable(GL_BLEND);
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glDepthMask(GL_FALSE);
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glBlendFunc(GL_ONE, GL_SRC_ALPHA);
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g_lodSphere->render(context,
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LODSphereMesh::Normals,
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frustum,
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ri.pixWidth,
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NULL);
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glDisable(GL_BLEND);
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glDepthMask(GL_TRUE);
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glFrontFace(GL_CCW);
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glPopMatrix();
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glx::glUseProgramObjectARB(0);
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//glx::glActiveTextureARB(GL_TEXTURE0_ARB);
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//glEnable(GL_TEXTURE_2D);
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}
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static void renderRingSystem(float innerRadius,
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float outerRadius,
|
|
float beginAngle,
|
|
float endAngle,
|
|
unsigned int nSections)
|
|
{
|
|
float angle = endAngle - beginAngle;
|
|
|
|
glBegin(GL_QUAD_STRIP);
|
|
for (unsigned int i = 0; i <= nSections; i++)
|
|
{
|
|
float t = (float) i / (float) nSections;
|
|
float theta = beginAngle + t * angle;
|
|
float s = (float) sin(theta);
|
|
float c = (float) cos(theta);
|
|
glTexCoord2f(0, 0.5f);
|
|
glVertex3f(c * innerRadius, 0, s * innerRadius);
|
|
glTexCoord2f(1, 0.5f);
|
|
glVertex3f(c * outerRadius, 0, s * outerRadius);
|
|
}
|
|
glEnd();
|
|
}
|
|
|
|
|
|
// Render a planetary ring system
|
|
void renderRings_GLSL(RingSystem& rings,
|
|
RenderInfo& ri,
|
|
const LightingState& ls,
|
|
float planetRadius,
|
|
float planetOblateness,
|
|
unsigned int textureResolution,
|
|
bool renderShadow,
|
|
unsigned int nSections)
|
|
{
|
|
float inner = rings.innerRadius / planetRadius;
|
|
float outer = rings.outerRadius / planetRadius;
|
|
Texture* ringsTex = rings.texture.find(textureResolution);
|
|
|
|
ShaderProperties shadprop;
|
|
// Set up the shader properties for ring rendering
|
|
{
|
|
shadprop.lightModel = ShaderProperties::RingIllumModel;
|
|
shadprop.nLights = min(ls.nLights, MaxShaderLights);
|
|
|
|
if (renderShadow)
|
|
{
|
|
// Set one shadow (the planet's) per light
|
|
for (unsigned int li = 0; li < ls.nLights; li++)
|
|
shadprop.setShadowCountForLight(li, 1);
|
|
}
|
|
|
|
if (ringsTex)
|
|
shadprop.texUsage = ShaderProperties::DiffuseTexture;
|
|
}
|
|
|
|
|
|
// Get a shader for the current rendering configuration
|
|
CelestiaGLProgram* prog = GetShaderManager().getShader(shadprop);
|
|
if (prog == NULL)
|
|
return;
|
|
|
|
prog->use();
|
|
|
|
prog->eyePosition = ls.eyePos_obj;
|
|
prog->ambientColor = Vec3f(ri.ambientColor.red(), ri.ambientColor.green(),
|
|
ri.ambientColor.blue());
|
|
prog->setLightParameters(ls, ri.color, ri.specularColor, Color::Black);
|
|
|
|
for (unsigned int li = 0; li < ls.nLights; li++)
|
|
{
|
|
const DirectionalLight& light = ls.lights[li];
|
|
|
|
// Compute the projection vectors based on the sun direction.
|
|
// I'm being a little careless here--if the sun direction lies
|
|
// along the y-axis, this will fail. It's unlikely that a
|
|
// planet would ever orbit underneath its sun (an orbital
|
|
// inclination of 90 degrees), but this should be made
|
|
// more robust anyway.
|
|
Vec3f axis = Vec3f(0, 1, 0) ^ light.direction_obj;
|
|
float cosAngle = Vec3f(0.0f, 1.0f, 0.0f) * light.direction_obj;
|
|
/*float angle = (float) acos(cosAngle); Unused*/
|
|
axis.normalize();
|
|
|
|
float tScale = 1.0f;
|
|
if (planetOblateness != 0.0f)
|
|
{
|
|
// For oblate planets, the size of the shadow volume will vary
|
|
// based on the light direction.
|
|
|
|
// A vertical slice of the planet is an ellipse
|
|
float a = 1.0f; // semimajor axis
|
|
float b = a * (1.0f - planetOblateness); // semiminor axis
|
|
float ecc2 = 1.0f - (b * b) / (a * a); // square of eccentricity
|
|
|
|
// Calculate the radius of the ellipse at the incident angle of the
|
|
// light on the ring plane + 90 degrees.
|
|
float r = a * (float) sqrt((1.0f - ecc2) /
|
|
(1.0f - ecc2 * square(cosAngle)));
|
|
|
|
tScale *= a / r;
|
|
}
|
|
|
|
// The s axis is perpendicular to the shadow axis in the plane of the
|
|
// of the rings, and the t axis completes the orthonormal basis.
|
|
Vec3f sAxis = axis * 0.5f;
|
|
Vec3f tAxis = (axis ^ light.direction_obj) * 0.5f * tScale;
|
|
Vec4f texGenS(sAxis.x, sAxis.y, sAxis.z, 0.5f);
|
|
Vec4f texGenT(tAxis.x, tAxis.y, tAxis.z, 0.5f);
|
|
|
|
// r0 and r1 determine the size of the penumbra and the umbra
|
|
// shadow size.
|
|
float r0 = 0.24f;
|
|
float r1 = 0.25f;
|
|
float bias = 1.0f / (1.0f - r1 / r0);
|
|
/*float scale = -bias / r0; Unused*/
|
|
|
|
prog->shadows[li][0].texGenS = texGenS;
|
|
prog->shadows[li][0].texGenT = texGenT;
|
|
prog->shadows[li][0].bias = bias;
|
|
prog->shadows[li][0].scale = -bias / r0;
|
|
}
|
|
|
|
glEnable(GL_BLEND);
|
|
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
|
|
|
|
if (ringsTex != NULL)
|
|
ringsTex->bind();
|
|
else
|
|
glDisable(GL_TEXTURE_2D);
|
|
|
|
renderRingSystem(inner, outer, 0, (float) PI * 2.0f, nSections);
|
|
renderRingSystem(inner, outer, (float) PI * 2.0f, 0, nSections);
|
|
|
|
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
|
|
|
|
glx::glUseProgramObjectARB(0);
|
|
}
|