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Diffstat (limited to 'indra/llrender/llrendersphere.cpp')
| -rw-r--r-- | indra/llrender/llrendersphere.cpp | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/indra/llrender/llrendersphere.cpp b/indra/llrender/llrendersphere.cpp new file mode 100644 index 0000000000..296fa77184 --- /dev/null +++ b/indra/llrender/llrendersphere.cpp @@ -0,0 +1,159 @@ +/** + * @file llrendersphere.cpp + * @brief implementation of the LLRenderSphere class. + * + * Copyright (c) 2001-$CurrentYear$, Linden Research, Inc. + * $License$ + */ + +// 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); +} + + +// lat = 0 is Z-axis +// lon = 0, lat = 90 at X-axis +void lat2xyz(LLVector3 * result, F32 lat, F32 lon) +{ + // Convert a latitude and longitude to x,y,z on a normal sphere and return it in result + F32 r; + result->mV[VX] = (F32) (cos(lon * DEG_TO_RAD) * sin(lat * DEG_TO_RAD)); + result->mV[VY] = (F32) (sin(lon * DEG_TO_RAD) * sin(lat * DEG_TO_RAD)); + r = (F32) pow(result->mV[VX] * result->mV[VX] + result->mV[VY] * result->mV[VY], 0.5f); + if (r == 1.0f) + { + result->mV[VZ] = 0.0f; + } + else + { + result->mV[VZ] = (F32) pow(1 - r*r, 0.5f); + if (lat > 90.01) + { + result->mV[VZ] *= -1.0; + } + } +} + +void lat2xyz_rad(LLVector3 * result, F32 lat, F32 lon) +{ + // Convert a latitude and longitude to x,y,z on a normal sphere and return it in result + F32 r; + result->mV[VX] = (F32) (cos(lon) * sin(lat)); + result->mV[VY] = (F32) (sin(lon) * sin(lat)); + r = (F32) pow(result->mV[VX] * result->mV[VX] + result->mV[VY] * result->mV[VY], 0.5f); + if (r == 1.0f) + result->mV[VZ] = 0.0f; + else + { + result->mV[VZ] = (F32) pow(1 - r*r, 0.5f); + if (lat > F_PI_BY_TWO) result->mV[VZ] *= -1.0; + } +} + +// 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]); +} |