X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Ffg_geometry.c;h=28d2c730d820f1e517fc53620d7d52202b2e9882;hb=3dbdb2176419cd2dabb3c19e1b24568bdc96be4e;hp=8d64ca34dfbc1d3bf3f93889d85b0bfc32646432;hpb=8353830076a254bcaeb71625d61fc283a2b7802c;p=freeglut diff --git a/src/fg_geometry.c b/src/fg_geometry.c index 8d64ca3..28d2c73 100644 --- a/src/fg_geometry.c +++ b/src/fg_geometry.c @@ -27,102 +27,292 @@ #include #include "fg_internal.h" +#include "fg_gl2.h" +#include /* - * TODO BEFORE THE STABLE RELEASE: - * - * See fghTetrahedron - * - * Following functions have been contributed by Andreas Umbach. - * - * glutWireCube() -- looks OK - * glutSolidCube() -- OK - * - * Those functions have been implemented by John Fay. - * - * glutWireTorus() -- looks OK - * glutSolidTorus() -- looks OK - * glutWireDodecahedron() -- looks OK - * glutSolidDodecahedron() -- looks OK - * glutWireOctahedron() -- looks OK - * glutSolidOctahedron() -- looks OK - * glutWireTetrahedron() -- looks OK - * glutSolidTetrahedron() -- looks OK - * glutWireIcosahedron() -- looks OK - * glutSolidIcosahedron() -- looks OK - * - * The Following functions have been updated by Nigel Stewart, based - * on FreeGLUT 2.0.0 implementations: - * - * glutWireSphere() -- looks OK - * glutSolidSphere() -- looks OK - * glutWireCone() -- looks OK - * glutSolidCone() -- looks OK + * Need more types of polyhedra? See CPolyhedron in MRPT */ -/* General function for drawing geometry. As for all geometry we have no - * redundancy (or hardly any in the case of cones and cylinders) in terms - * of the vertex/normal combinations, we just use glDrawArrays. - * useWireMode controls the drawing of solids (false) or wire frame - * versions (TRUE) of the geometry you pass +/* General functions for drawing geometry + * Solids are drawn by glDrawArrays if composed of triangles, or by + * glDrawElements if consisting of squares or pentagons that were + * decomposed into triangles (some vertices are repeated in that case). + * WireFrame drawing will have to be done per face, using GL_LINE_LOOP and + * issuing one draw call per face. Always use glDrawArrays as no triangle + * decomposition needed. We use the "first" parameter in glDrawArrays to go + * from face to face. */ -static void fghDrawGeometry(GLenum vertexMode, GLdouble* vertices, GLdouble* normals, GLsizei numVertices, GLboolean useWireMode) + +/* Version for OpenGL (ES) 1.1 */ +#ifndef GL_ES_VERSION_2_0 +static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals, GLsizei numFaces, GLsizei numEdgePerFace) { - if (useWireMode) - { - glPushAttrib(GL_POLYGON_BIT); - glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); - } + int i; + + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_NORMAL_ARRAY); - if (1) - { - glEnableClientState(GL_VERTEX_ARRAY); - glEnableClientState(GL_NORMAL_ARRAY); + glVertexPointer(3, GL_FLOAT, 0, vertices); + glNormalPointer(GL_FLOAT, 0, normals); + + /* Draw per face (TODO: could use glMultiDrawArrays if available) */ + for (i=0; i= 2.0 */ +static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei numFaces, GLsizei numEdgePerFace, + GLint attribute_v_coord, GLint attribute_v_normal) +{ + GLuint vbo_coords = 0, vbo_normals = 0; + GLuint numVertices = numFaces * numEdgePerFace; + + int i; + + if (numVertices > 0 && attribute_v_coord != -1) { + fghGenBuffers(1, &vbo_coords); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_coords); + fghBufferData(FGH_ARRAY_BUFFER, numVertices * 3 * sizeof(vertices[0]), + vertices, FGH_STATIC_DRAW); } - else - { - int i; - glBegin(vertexMode); - for(i=0; i 0 && attribute_v_normal != -1) { + fghGenBuffers(1, &vbo_normals); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_normals); + fghBufferData(FGH_ARRAY_BUFFER, numVertices * 3 * sizeof(normals[0]), + normals, FGH_STATIC_DRAW); + } + + if (vbo_coords) { + fghEnableVertexAttribArray(attribute_v_coord); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_coords); + fghVertexAttribPointer( + attribute_v_coord, /* attribute */ + 3, /* number of elements per vertex, here (x,y,z) */ + GL_FLOAT, /* the type of each element */ + GL_FALSE, /* take our values as-is */ + 0, /* no extra data between each position */ + 0 /* offset of first element */ + ); } - if (useWireMode) - { - glPopAttrib(); + if (vbo_normals) { + fghEnableVertexAttribArray(attribute_v_normal); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_normals); + fghVertexAttribPointer( + attribute_v_normal, /* attribute */ + 3, /* number of elements per vertex, here (x,y,z) */ + GL_FLOAT, /* the type of each element */ + GL_FALSE, /* take our values as-is */ + 0, /* no extra data between each position */ + 0 /* offset of first element */ + ); } + + /* Draw per face (TODO: could use glMultiDrawArrays if available) */ + for (i=0; iWindow.attribute_v_coord; + GLint attribute_v_normal = fgStructure.CurrentWindow->Window.attribute_v_normal; + + if (fgState.HasOpenGL20 && (attribute_v_coord != -1 || attribute_v_normal != -1)) + /* User requested a 2.0 draw */ + fghDrawGeometryWire20(vertices, normals, numFaces, numEdgePerFace, + attribute_v_coord, attribute_v_normal); +#ifndef GL_ES_VERSION_2_0 + else + fghDrawGeometryWire11(vertices, normals, numFaces, numEdgePerFace); +#endif +} + + +/* Draw the geometric shape with filled triangles + * + * - If the shape is naturally triangulated (numEdgePerFace==3), each + * vertex+normal pair is used only once, so no vertex indices. + * + * - If the shape was triangulated (DECOMPOSE_TO_TRIANGLE), some + * vertex+normal pairs are reused, so use vertex indices. + */ + +/* Version for OpenGL (ES) 1.1 */ +#ifndef GL_ES_VERSION_2_0 +static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLubyte *vertIdxs, + GLsizei numVertices, GLsizei numVertIdxs) +{ + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_NORMAL_ARRAY); + + glVertexPointer(3, GL_FLOAT, 0, vertices); + glNormalPointer(GL_FLOAT, 0, normals); + if (vertIdxs == NULL) + glDrawArrays(GL_TRIANGLES, 0, numVertices); + else + glDrawElements(GL_TRIANGLES, numVertIdxs, GL_UNSIGNED_BYTE, vertIdxs); + + glDisableClientState(GL_VERTEX_ARRAY); + glDisableClientState(GL_NORMAL_ARRAY); +} +#endif + +/* Version for OpenGL (ES) >= 2.0 */ +static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLubyte *vertIdxs, + GLsizei numVertices, GLsizei numVertIdxs, + GLint attribute_v_coord, GLint attribute_v_normal) +{ + GLuint vbo_coords = 0, vbo_normals = 0, ibo_elements = 0; + + if (numVertices > 0 && attribute_v_coord != -1) { + fghGenBuffers(1, &vbo_coords); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_coords); + fghBufferData(FGH_ARRAY_BUFFER, numVertices * 3 * sizeof(vertices[0]), + vertices, FGH_STATIC_DRAW); + } + + if (numVertices > 0 && attribute_v_normal != -1) { + fghGenBuffers(1, &vbo_normals); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_normals); + fghBufferData(FGH_ARRAY_BUFFER, numVertices * 3 * sizeof(normals[0]), + normals, FGH_STATIC_DRAW); + } + + if (vertIdxs != NULL) { + fghGenBuffers(1, &ibo_elements); + fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, ibo_elements); + fghBufferData(FGH_ELEMENT_ARRAY_BUFFER, numVertIdxs * sizeof(vertIdxs[0]), + vertIdxs, FGH_STATIC_DRAW); + } + + if (vbo_coords) { + fghEnableVertexAttribArray(attribute_v_coord); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_coords); + fghVertexAttribPointer( + attribute_v_coord, /* attribute */ + 3, /* number of elements per vertex, here (x,y,z) */ + GL_FLOAT, /* the type of each element */ + GL_FALSE, /* take our values as-is */ + 0, /* no extra data between each position */ + 0 /* offset of first element */ + ); + }; + + if (vbo_normals) { + fghEnableVertexAttribArray(attribute_v_normal); + fghBindBuffer(FGH_ARRAY_BUFFER, vbo_normals); + fghVertexAttribPointer( + attribute_v_normal, /* attribute */ + 3, /* number of elements per vertex, here (x,y,z) */ + GL_FLOAT, /* the type of each element */ + GL_FALSE, /* take our values as-is */ + 0, /* no extra data between each position */ + 0 /* offset of first element */ + ); + }; + + if (vertIdxs == NULL) { + glDrawArrays(GL_TRIANGLES, 0, numVertices); + } else { + fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, ibo_elements); + glDrawElements(GL_TRIANGLES, numVertIdxs, GL_UNSIGNED_BYTE, 0); + } + + /* Clean existing bindings before clean-up */ + /* Android showed instability otherwise */ + fghBindBuffer(FGH_ARRAY_BUFFER, 0); + fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, 0); + + if (vbo_coords != 0) + fghDisableVertexAttribArray(attribute_v_coord); + if (vbo_normals != 0) + fghDisableVertexAttribArray(attribute_v_normal); + + if (vbo_coords != 0) + fghDeleteBuffers(1, &vbo_coords); + if (vbo_normals != 0) + fghDeleteBuffers(1, &vbo_normals); + if (ibo_elements != 0) + fghDeleteBuffers(1, &ibo_elements); +} + +static void fghDrawGeometrySolid(GLfloat *vertices, GLfloat *normals, GLubyte *vertIdxs, + GLsizei numVertices, GLsizei numVertIdxs) +{ + GLint attribute_v_coord = fgStructure.CurrentWindow->Window.attribute_v_coord; + GLint attribute_v_normal = fgStructure.CurrentWindow->Window.attribute_v_normal; + + if (fgState.HasOpenGL20 && (attribute_v_coord != -1 || attribute_v_normal != -1)) + /* User requested a 2.0 draw */ + fghDrawGeometrySolid20(vertices, normals, vertIdxs, + numVertices, numVertIdxs, + attribute_v_coord, attribute_v_normal); +#ifndef GL_ES_VERSION_2_0 + else + fghDrawGeometrySolid11(vertices, normals, vertIdxs, + numVertices, numVertIdxs); +#endif +} + +/* Shape decomposition to triangles + * We'll use glDrawElements to draw all shapes that are not naturally + * composed of triangles, so generate an index vector here, using the + * below sampling scheme. + * Be careful to keep winding of all triangles counter-clockwise, + * assuming that input has correct winding... + */ +static GLubyte vert4Decomp[6] = {0,1,2, 0,2,3}; /* quad : 4 input vertices, 6 output (2 triangles) */ +static GLubyte vert5Decomp[9] = {0,1,2, 0,2,4, 4,2,3}; /* pentagon: 5 input vertices, 9 output (3 triangles) */ + +static void fghGenerateGeometryWithIndexArray(int numFaces, int numEdgePerFace, GLfloat *vertices, GLubyte *vertIndices, GLfloat *normals, GLfloat *vertOut, GLfloat *normOut, GLubyte *vertIdxOut) +{ + int i,j,numEdgeIdxPerFace; + GLubyte *vertSamps = NULL; + switch (numEdgePerFace) + { + case 3: + /* nothing to do here, we'll draw with glDrawArrays */ + break; + case 4: + vertSamps = vert4Decomp; + numEdgeIdxPerFace = 6; /* 6 output vertices for each face */ + break; + case 5: + vertSamps = vert5Decomp; + numEdgeIdxPerFace = 9; /* 9 output vertices for each face */ + break; + } /* - * Build array with vertices from vertex coordinates and vertex indices + * Build array with vertices using vertex coordinates and vertex indices * Do same for normals. - * Need to do this because of different normals at shared vertices - * (and because normals' coordinates need to be negated). + * Need to do this because of different normals at shared vertices. */ for (i=0; i 0 ) { - GLdouble local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */ + double local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */ unsigned int stride = ipow(4,--numLevels)*TETRAHEDRON_VERT_ELEM_PER_OBJ; scale /= 2.0 ; for ( i = 0 ; i < TETRAHEDRON_NUM_FACES ; i++ ) @@ -469,9 +762,11 @@ static void fghSierpinskiSpongeGenerate ( int numLevels, GLdouble offset[3], GLd } } +#ifndef GL_ES_VERSION_2_0 /* -- Now the various shapes involving circles -- */ /* - * Compute lookup table of cos and sin values forming a cirle + * Compute lookup table of cos and sin values forming a circle + * (or half circle if halfCircle==TRUE) * * Notes: * It is the responsibility of the caller to free these tables @@ -479,25 +774,21 @@ static void fghSierpinskiSpongeGenerate ( int numLevels, GLdouble offset[3], GLd * The last entry is exactly the same as the first * The sign of n can be flipped to get the reverse loop */ -static void fghCircleTable(double **sint,double **cost,const int n) +static void fghCircleTable(GLfloat **sint, GLfloat **cost, const int n, const GLboolean halfCircle) { int i; - + /* Table size, the sign of n flips the circle direction */ - const int size = abs(n); /* Determine the angle between samples */ - - const double angle = 2*M_PI/(double)( ( n == 0 ) ? 1 : n ); + const GLfloat angle = (halfCircle?1:2)*(GLfloat)M_PI/(GLfloat)( ( n == 0 ) ? 1 : n ); /* Allocate memory for n samples, plus duplicate of first entry at the end */ - - *sint = (double *) calloc(sizeof(double), size+1); - *cost = (double *) calloc(sizeof(double), size+1); + *sint = malloc(sizeof(GLfloat) * (size+1)); + *cost = malloc(sizeof(GLfloat) * (size+1)); /* Bail out if memory allocation fails, fgError never returns */ - if (!(*sint) || !(*cost)) { free(*sint); @@ -506,788 +797,1058 @@ static void fghCircleTable(double **sint,double **cost,const int n) } /* Compute cos and sin around the circle */ - (*sint)[0] = 0.0; (*cost)[0] = 1.0; for (i=1; i0)?1:0]; - r0 = 0.0; - r1 = sint2[(stacks>0)?1:0]; - - glBegin(GL_TRIANGLE_FAN); - - glNormal3d(0,0,1); - glVertex3d(0,0,radius); - - for (j=slices; j>=0; j--) - { - glNormal3d(cost1[j]*r1, sint1[j]*r1, z1 ); - glVertex3d(cost1[j]*r1*radius, sint1[j]*r1*radius, z1*radius); - } - - glEnd(); - - /* Cover each stack with a quad strip, except the top and bottom stacks */ - - for( i=1; i 65535) /* TODO: must have a better solution than this low limit, at least for architectures where gluint is available */ + fgWarning("fghGenerateSphere: too many slices or stacks requested, indices will wrap"); + + /* precompute values on unit circle */ + fghCircleTable(&sint1,&cost1,-slices,FALSE); + fghCircleTable(&sint2,&cost2, stacks,TRUE); + + /* Allocate vertex and normal buffers, bail out if memory allocation fails */ + *vertices = malloc((*nVert)*3*sizeof(GLfloat)); + *normals = malloc((*nVert)*3*sizeof(GLfloat)); + if (!(*vertices) || !(*normals)) + { + free(*vertices); + free(*normals); + fgError("Failed to allocate memory in fghGenerateSphere"); } - /* The bottom stack is covered with a triangle fan */ - - z0 = z1; - r0 = r1; - - glBegin(GL_TRIANGLE_FAN); - - glNormal3d(0,0,-1); - glVertex3d(0,0,-radius); - - for (j=0; j<=slices; j++) + /* top */ + (*vertices)[0] = 0.f; + (*vertices)[1] = 0.f; + (*vertices)[2] = radius; + (*normals )[0] = 0.f; + (*normals )[1] = 0.f; + (*normals )[2] = 1.f; + idx = 3; + + /* each stack */ + for( i=1; i 0 ) ? stacks : 1 ); + const GLfloat rStep = (GLfloat)base / ( ( stacks > 0 ) ? stacks : 1 ); - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireSphere" ); + /* Scaling factors for vertex normals */ +#ifdef __cplusplus + const GLfloat cosn = ( (GLfloat)height / sqrtf( height * height + base * base )); + const GLfloat sinn = ( (GLfloat)base / sqrtf( height * height + base * base )); +#else + const GLfloat cosn = ( (GLfloat)height / (GLfloat)sqrt( (double)(height * height + base * base) )); + const GLfloat sinn = ( (GLfloat)base / (GLfloat)sqrt( (double)(height * height + base * base) )); +#endif /* __cplusplus */ - fghCircleTable(&sint1,&cost1,-slices ); - fghCircleTable(&sint2,&cost2, stacks*2); - /* Draw a line loop for each stack */ - for (i=1; i 65535) + fgWarning("fghGenerateCone: too many slices or stacks requested, indices will wrap"); - glNormal3d(x,y,z); - glVertex3d(x*r*radius,y*r*radius,z*radius); - } + /* Pre-computed circle */ + fghCircleTable(&sint,&cost,-slices,FALSE); - glEnd(); + /* Allocate vertex and normal buffers, bail out if memory allocation fails */ + *vertices = malloc((*nVert)*3*sizeof(GLfloat)); + *normals = malloc((*nVert)*3*sizeof(GLfloat)); + if (!(*vertices) || !(*normals)) + { + free(*vertices); + free(*normals); + fgError("Failed to allocate memory in fghGenerateSphere"); } - /* Draw a line loop for each slice */ - - for (i=0; i 0 ) ? stacks : 1 ); - const double zStep = height / ( ( stacks > 0 ) ? stacks : 1 ); - const double rStep = base / ( ( stacks > 0 ) ? stacks : 1 ); + /* Pre-computed circle */ + GLfloat *sint,*cost; - /* Scaling factors for vertex normals */ + /* number of unique vertices */ + if (slices==0 || stacks<1) + { + /* nothing to generate */ + *nVert = 0; + return; + } + *nVert = slices*(stacks+3)+2; /* need two extra stacks for closing off top and bottom with correct normals */ - const double cosn = ( height / sqrt ( height * height + base * base )); - const double sinn = ( base / sqrt ( height * height + base * base )); + if ((*nVert) > 65535) + fgWarning("fghGenerateCylinder: too many slices or stacks requested, indices will wrap"); /* Pre-computed circle */ + fghCircleTable(&sint,&cost,-slices,FALSE); - double *sint,*cost; - - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCone" ); - - fghCircleTable(&sint,&cost,-slices); + /* Allocate vertex and normal buffers, bail out if memory allocation fails */ + *vertices = malloc((*nVert)*3*sizeof(GLfloat)); + *normals = malloc((*nVert)*3*sizeof(GLfloat)); + if (!(*vertices) || !(*normals)) + { + free(*vertices); + free(*normals); + fgError("Failed to allocate memory in fghGenerateCylinder"); + } - /* Cover the circular base with a triangle fan... */ + z=0; + /* top on Z-axis */ + (*vertices)[0] = 0.f; + (*vertices)[1] = 0.f; + (*vertices)[2] = 0.f; + (*normals )[0] = 0.f; + (*normals )[1] = 0.f; + (*normals )[2] = -1.f; + idx = 3; + /* other on top (get normals right) */ + for (j=0; j 65535) + fgWarning("fghGenerateTorus: too many slices or stacks requested, indices will wrap"); - z0 = z1; z1 += zStep; - r0 = r1; r1 -= rStep; + /* precompute values on unit circle */ + fghCircleTable(&spsi,&cpsi, nRings,FALSE); + fghCircleTable(&sphi,&cphi,-nSides,FALSE); - glEnd(); + /* Allocate vertex and normal buffers, bail out if memory allocation fails */ + *vertices = malloc((*nVert)*3*sizeof(GLfloat)); + *normals = malloc((*nVert)*3*sizeof(GLfloat)); + if (!(*vertices) || !(*normals)) + { + free(*vertices); + free(*normals); + fgError("Failed to allocate memory in fghGenerateTorus"); } - /* The top stack is covered with individual triangles */ - - glBegin(GL_TRIANGLES); - - glNormal3d(cost[0]*sinn, sint[0]*sinn, cosn); - - for (j=0; j 0 ) ? stacks : 1 ); - const double rStep = base / ( ( stacks > 0 ) ? stacks : 1 ); + if (dSize!=1.f) + { + /* Need to build new vertex list containing vertices for cube of different size */ + int i; - /* Scaling factors for vertex normals */ + vertices = malloc(CUBE_VERT_ELEM_PER_OBJ * sizeof(GLfloat)); - const double cosn = ( height / sqrt ( height * height + base * base )); - const double sinn = ( base / sqrt ( height * height + base * base )); + /* Bail out if memory allocation fails, fgError never returns */ + if (!vertices) + { + free(vertices); + fgError("Failed to allocate memory in fghCube"); + } - /* Pre-computed circle */ + for (i=0; i 0 ) ? stacks : 1 ); + /* middle stacks: */ + /* Strip indices are relative to first index belonging to strip, NOT relative to first vertex/normal pair in array */ + for (i=0; i=0; j--) - glVertex3d(cost[j]*radius, sint[j]*radius, height); - glEnd(); +static void fghCone( double base, double height, GLint slices, GLint stacks, GLboolean useWireMode ) +{ + int i,j,idx, nVert; + GLfloat *vertices, *normals; - /* Do the stacks */ + /* Generate vertices and normals */ + /* Note, (stacks+1)*slices vertices for side of object, slices+1 for top and bottom closures */ + fghGenerateCone((GLfloat)base,(GLfloat)height,slices,stacks,&vertices,&normals,&nVert); - z0 = 0.0; - z1 = zStep; + if (nVert==0) + /* nothing to draw */ + return; - for (i=1; i<=stacks; i++) + if (useWireMode) { - if (i==stacks) - z1 = height; + GLushort *sliceIdx, *stackIdx; + /* First, generate vertex index arrays for drawing with glDrawElements + * We have a bunch of line_loops to draw for each stack, and a + * bunch for each slice. + */ + + stackIdx = malloc(slices*stacks*sizeof(GLushort)); + sliceIdx = malloc(slices*2 *sizeof(GLushort)); + if (!(stackIdx) || !(sliceIdx)) + { + free(stackIdx); + free(sliceIdx); + fgError("Failed to allocate memory in fghGenerateCone"); + } - glBegin(GL_QUAD_STRIP); - for (j=0; j<=slices; j++ ) + /* generate for each stack */ + for (i=0,idx=0; i 0 ) ? stacks : 1 ); + glDisableClientState(GL_VERTEX_ARRAY); + glDisableClientState(GL_NORMAL_ARRAY); - /* Pre-computed circle */ + /* cleanup allocated memory */ + free(stripIdx); + } - double *sint,*cost; + /* cleanup allocated memory */ + free(vertices); + free(normals); +} - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCylinder" ); +static void fghCylinder( double radius, double height, GLint slices, GLint stacks, GLboolean useWireMode ) +{ + int i,j,idx, nVert; + GLfloat *vertices, *normals; - fghCircleTable(&sint,&cost,-slices); + /* Generate vertices and normals */ + /* Note, (stacks+1)*slices vertices for side of object, 2*slices+2 for top and bottom closures */ + fghGenerateCylinder((GLfloat)radius,(GLfloat)height,slices,stacks,&vertices,&normals,&nVert); - /* Draw the stacks... */ + if (nVert==0) + /* nothing to draw */ + return; - for (i=0; i<=stacks; i++) + if (useWireMode) { - if (i==stacks) - z = height; - - glBegin(GL_LINE_LOOP); + GLushort *sliceIdx, *stackIdx; + /* First, generate vertex index arrays for drawing with glDrawElements + * We have a bunch of line_loops to draw for each stack, and a + * bunch for each slice. + */ + + stackIdx = malloc(slices*(stacks+1)*sizeof(GLushort)); + sliceIdx = malloc(slices*2 *sizeof(GLushort)); + if (!(stackIdx) || !(sliceIdx)) + { + free(stackIdx); + free(sliceIdx); + fgError("Failed to allocate memory in fghGenerateCylinder"); + } - for( j=0; j