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Diffstat (limited to 'indra/llrender/llrendersphere.cpp')
| -rw-r--r-- | indra/llrender/llrendersphere.cpp | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/indra/llrender/llrendersphere.cpp b/indra/llrender/llrendersphere.cpp new file mode 100644 index 0000000000..a5cd70445f --- /dev/null +++ b/indra/llrender/llrendersphere.cpp @@ -0,0 +1,185 @@ +/** + * @file llrendersphere.cpp + * @brief implementation of the LLRenderSphere class. + * + * $LicenseInfo:firstyear=2001&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2010, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +// Sphere creates a set of display lists that can then be called to create +// a lit sphere at different LOD levels. You only need one instance of sphere +// per viewer - then call the appropriate list. + +#include "linden_common.h" + +#include "llrendersphere.h" +#include "llerror.h" + +#include "llglheaders.h" + +GLUquadricObj *gQuadObj2 = NULL; +LLRenderSphere gSphere; + +void drawSolidSphere(GLdouble radius, GLint slices, GLint stacks); + +void drawSolidSphere(GLdouble radius, GLint slices, GLint stacks) +{ + if (!gQuadObj2) + { + gQuadObj2 = gluNewQuadric(); + if (!gQuadObj2) + { + llwarns << "drawSolidSphere couldn't allocate quadric" << llendl; + return; + } + } + + gluQuadricDrawStyle(gQuadObj2, GLU_FILL); + gluQuadricNormals(gQuadObj2, GLU_SMOOTH); + // If we ever changed/used the texture or orientation state + // of quadObj, we'd need to change it to the defaults here + // with gluQuadricTexture and/or gluQuadricOrientation. + gluQuadricTexture(gQuadObj2, GL_TRUE); + gluSphere(gQuadObj2, radius, slices, stacks); +} + + +// A couple thoughts on sphere drawing: +// 1) You need more slices than stacks, but little less than 2:1 +// 2) At low LOD, setting stacks to an odd number avoids a "band" around the equator, making things look smoother +void LLRenderSphere::prerender() +{ + // Create a series of display lists for different LODs + mDList[0] = glGenLists(1); + glNewList(mDList[0], GL_COMPILE); + drawSolidSphere(1.0, 30, 20); + glEndList(); + + mDList[1] = glGenLists(1); + glNewList(mDList[1], GL_COMPILE); + drawSolidSphere(1.0, 20, 15); + glEndList(); + + mDList[2] = glGenLists(1); + glNewList(mDList[2], GL_COMPILE); + drawSolidSphere(1.0, 12, 8); + glEndList(); + + mDList[3] = glGenLists(1); + glNewList(mDList[3], GL_COMPILE); + drawSolidSphere(1.0, 8, 5); + glEndList(); +} + +void LLRenderSphere::cleanupGL() +{ + for (S32 detail = 0; detail < 4; detail++) + { + glDeleteLists(mDList[detail], 1); + mDList[detail] = 0; + } + + if (gQuadObj2) + { + gluDeleteQuadric(gQuadObj2); + gQuadObj2 = NULL; + } +} + +// Constants here are empirically derived from my eyeballs, JNC +// +// The toughest adjustment is the cutoff for the lowest LOD +// Maybe we should have more LODs at the low end? +void LLRenderSphere::render(F32 pixel_area) +{ + S32 level_of_detail; + + if (pixel_area > 10000.f) + { + level_of_detail = 0; + } + else if (pixel_area > 800.f) + { + level_of_detail = 1; + } + else if (pixel_area > 100.f) + { + level_of_detail = 2; + } + else + { + level_of_detail = 3; + } + glCallList(mDList[level_of_detail]); +} + + +void LLRenderSphere::render() +{ + glCallList(mDList[0]); +} + +inline LLVector3 polar_to_cart(F32 latitude, F32 longitude) +{ + return LLVector3(sin(F_TWO_PI * latitude) * cos(F_TWO_PI * longitude), + sin(F_TWO_PI * latitude) * sin(F_TWO_PI * longitude), + cos(F_TWO_PI * latitude)); +} + + +void LLRenderSphere::renderGGL() +{ + S32 const LATITUDE_SLICES = 20; + S32 const LONGITUDE_SLICES = 30; + + if (mSpherePoints.empty()) + { + mSpherePoints.resize(LATITUDE_SLICES + 1); + for (S32 lat_i = 0; lat_i < LATITUDE_SLICES + 1; lat_i++) + { + mSpherePoints[lat_i].resize(LONGITUDE_SLICES + 1); + for (S32 lon_i = 0; lon_i < LONGITUDE_SLICES + 1; lon_i++) + { + F32 lat = (F32)lat_i / LATITUDE_SLICES; + F32 lon = (F32)lon_i / LONGITUDE_SLICES; + + mSpherePoints[lat_i][lon_i] = polar_to_cart(lat, lon); + } + } + } + + gGL.begin(LLRender::TRIANGLES); + + for (S32 lat_i = 0; lat_i < LATITUDE_SLICES; lat_i++) + { + for (S32 lon_i = 0; lon_i < LONGITUDE_SLICES; lon_i++) + { + gGL.vertex3fv(mSpherePoints[lat_i][lon_i].mV); + gGL.vertex3fv(mSpherePoints[lat_i][lon_i+1].mV); + gGL.vertex3fv(mSpherePoints[lat_i+1][lon_i].mV); + + gGL.vertex3fv(mSpherePoints[lat_i+1][lon_i].mV); + gGL.vertex3fv(mSpherePoints[lat_i][lon_i+1].mV); + gGL.vertex3fv(mSpherePoints[lat_i+1][lon_i+1].mV); + } + } + gGL.end(); +} |