*/
-/* 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(GLdouble *vertices, GLdouble *normals, GLboolean *edgeFlags, GLsizei numVertices, GLsizei numFaces, GLsizei numEdgePerFace, GLboolean useWireMode)
+static void fghDrawGeometryWire(GLdouble *vertices, GLdouble *normals, GLsizei numFaces, GLsizei numEdgePerFace)
{
-# ifdef FREEGLUT_GLES1
- /* Solid drawing is the same for OpenGL 1.x and OpenGL ES 1.x, just
- * no edge flags for ES.
- * WireFrame drawing will have to be done per face though, using
- * GL_LINE_LOOP and issuing one draw call per face. For triangles,
- * we use glDrawArrays directly on the vertex data for each face,
- * while for shapes that are composed of quads or pentagons, we use
- * glDrawElements with index vector {0,1,2,5} or {0,1,2,8,5},
- * respectively.
- * We use the first parameter in glDrawArrays or glDrawElements to
- * go from face to face.
- */
- if (useWireMode)
- {
- /* setup reading the right elements from vertex array */
- GLubyte vertIdx4[4] = {0,1,2,5};
- GLubyte vertIdx5[5] = {0,1,2,8,5};
- GLubyte *indices = NULL;
- int vertStride, i, j;
-
- switch (numEdgePerFace)
- {
- case 3:
- vertStride = 3; /* there are 3 vertices for each face in the array */
- break;
- case 4:
- indices = vertIdx4;
- vertStride = 6; /* there are 6 vertices for each face in the array */
- break;
- case 5:
- indices = vertIdx5;
- vertStride = 9; /* there are 9 vertices for each face in the array */
- break;
- }
-
- glEnableClientState(GL_VERTEX_ARRAY);
- glEnableClientState(GL_NORMAL_ARRAY);
-
- glVertexPointer(3, GL_DOUBLE, 0, vertices);
- glNormalPointer(GL_DOUBLE, 0, normals);
-
- if (numEdgePerFace==3)
- for (i=0; i<numFaces; i++)
- glDrawArrays(GL_LINE_LOOP, i*vertStride, numEdgePerFace);
- else
- {
- GLubyte *vertIndices = malloc(numEdgePerFace*sizeof(GLubyte));
- for (i=0; i<numFaces; i++)
- {
- for (j=0; j< numEdgePerFace; j++)
- vertIndices[j] = indices[j]+i*vertStride;
-
- glDrawElements(GL_LINE_LOOP, numEdgePerFace, GL_UNSIGNED_BYTE, vertIndices);
- }
- free(vertIndices);
- }
+ int i;
+
+ glEnableClientState(GL_VERTEX_ARRAY);
+ glEnableClientState(GL_NORMAL_ARRAY);
- glDisableClientState(GL_VERTEX_ARRAY);
- glDisableClientState(GL_NORMAL_ARRAY);
- return; /* done */
- }
-# endif
+ glVertexPointer(3, GL_DOUBLE, 0, vertices);
+ glNormalPointer(GL_DOUBLE, 0, normals);
- if (useWireMode)
- {
- glPushAttrib(GL_POLYGON_BIT);
- glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
- glDisable(GL_CULL_FACE);
- }
+ /* Draw per face (TODO: could use glMultiDrawArrays if available) */
+ for (i=0; i<numFaces; i++)
+ glDrawArrays(GL_LINE_LOOP, i*numEdgePerFace, numEdgePerFace);
+ glDisableClientState(GL_VERTEX_ARRAY);
+ glDisableClientState(GL_NORMAL_ARRAY);
+}
+static void fghDrawGeometrySolid(GLdouble *vertices, GLdouble *normals, GLubyte *vertIdxs, GLsizei numVertices, GLsizei numEdgePerFace)
+{
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
-# ifndef FREEGLUT_GLES1
- if (edgeFlags)
- glEnableClientState(GL_EDGE_FLAG_ARRAY);
-# endif
glVertexPointer(3, GL_DOUBLE, 0, vertices);
glNormalPointer(GL_DOUBLE, 0, normals);
-# ifndef FREEGLUT_GLES1
- if (edgeFlags)
- glEdgeFlagPointer(0,edgeFlags);
-# endif
- glDrawArrays(GL_TRIANGLES, 0, numVertices);
+ if (numEdgePerFace==3)
+ glDrawArrays(GL_TRIANGLES, 0, numVertices);
+ else
+ glDrawElements(GL_TRIANGLES, numVertices, GL_UNSIGNED_BYTE, vertIdxs);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
-# ifndef FREEGLUT_GLES1
- if (edgeFlags)
- glDisableClientState(GL_EDGE_FLAG_ARRAY);
-# endif
-
- if (useWireMode)
- {
- glPopAttrib();
- }
-
- /* Notes on OpenGL 3 and OpenGL ES2, drawing code for programmable pipeline:
- * As above, we'll have to draw face-by-face for wireframes. On
- * OpenGL 3 we can probably use glMultiDrawArrays do do this efficiently.
- * other complications are VBOs and such...
- */
}
-/* Triangle decomposition and associated edgeFlags generation
+/* Shape decomposition to triangles
+ * We'll use glDrawElements to draw all shapes that are not 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...
- * Could probably do something smarter using glDrawElements and generating
- * an index vector here for all shapes that are not triangles, but this
- * suffices for now. We're not talking many vertices in our objects anyway.
*/
-static GLubyte vertSamp3[3] = {0,1,2};
-static GLubyte vertSamp4[6] = {0,1,2, 0,2,3}; /* quad : 4 input vertices, 6 output (2 triangles) */
-static GLubyte vertSamp5[9] = {0,1,2, 0,2,4, 4,2,3}; /* pentagon: 5 input vertices, 9 output (3 triangles) */
-static GLboolean edgeFlag3[3] = {1,1,1}; /* triangles remain triangles, all edges are external */
-static GLboolean edgeFlag4[6] = {1,1,0, 0,1,1};
-static GLboolean edgeFlag5[9] = {1,1,0, 0,0,1, 0,1,1};
-
-static void fghGenerateGeometryWithEdgeFlag(int numFaces, int numEdgePerFaceIn, GLdouble *vertices, GLubyte *vertIndices, GLdouble *normals, GLdouble *vertOut, GLdouble *normOut, GLboolean *edgeFlagsOut)
+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, GLdouble *vertices, GLubyte *vertIndices, GLdouble *normals, GLdouble *vertOut, GLdouble *normOut, GLubyte *vertIdxOut)
{
- int i,j,numEdgePerFaceOut;
+ int i,j,numEdgeIdxPerFace;
GLubyte *vertSamps = NULL;
- GLboolean *edgeFlags = NULL;
- switch (numEdgePerFaceIn)
+ switch (numEdgePerFace)
{
case 3:
- vertSamps = vertSamp3;
- edgeFlags = edgeFlag3;
- numEdgePerFaceOut = 3; /* 3 output vertices for each face */
+ /* nothing to do here, we'll drawn with glDrawArrays */
break;
case 4:
- vertSamps = vertSamp4;
- edgeFlags = edgeFlag4;
- numEdgePerFaceOut = 6; /* 6 output vertices for each face */
+ vertSamps = vert4Decomp;
+ numEdgeIdxPerFace = 6; /* 6 output vertices for each face */
break;
case 5:
- vertSamps = vertSamp5;
- edgeFlags = edgeFlag5;
- numEdgePerFaceOut = 9; /* 9 output vertices for each face */
+ 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<numFaces; i++)
{
int normIdx = i*3;
- int faceIdxVertIdx = i*numEdgePerFaceIn; // index to first element of "row" in vertex indices
- for (j=0; j<numEdgePerFaceOut; j++)
+ int faceIdxVertIdx = i*numEdgePerFace; // index to first element of "row" in vertex indices
+ for (j=0; j<numEdgePerFace; j++)
{
- int outIdx = i*numEdgePerFaceOut*3+j*3;
- int vertIdx = vertIndices[faceIdxVertIdx+vertSamps[j]]*3;
+ int outIdx = i*numEdgePerFace*3+j*3;
+ int vertIdx = vertIndices[faceIdxVertIdx+j]*3;
vertOut[outIdx ] = vertices[vertIdx ];
vertOut[outIdx+1] = vertices[vertIdx+1];
normOut[outIdx ] = normals [normIdx ];
normOut[outIdx+1] = normals [normIdx+1];
normOut[outIdx+2] = normals [normIdx+2];
-
- if (edgeFlagsOut)
- edgeFlagsOut[i*numEdgePerFaceOut+j] = edgeFlags[j];
}
+
+ /* generate vertex indices for each face */
+ if (vertSamps)
+ for (j=0; j<numEdgeIdxPerFace; j++)
+ vertIdxOut[i*numEdgeIdxPerFace+j] = faceIdxVertIdx + vertSamps[j];
}
}
static void fghGenerateGeometry(int numFaces, int numEdgePerFace, GLdouble *vertices, GLubyte *vertIndices, GLdouble *normals, GLdouble *vertOut, GLdouble *normOut)
{
- fghGenerateGeometryWithEdgeFlag(numFaces, numEdgePerFace, vertices, vertIndices, normals, vertOut, normOut, NULL);
+ /* This function does the same as fghGenerateGeometryWithIndexArray, just skipping the index array generation... */
+ fghGenerateGeometryWithIndexArray(numFaces, numEdgePerFace, vertices, vertIndices, normals, vertOut, normOut, NULL);
}
/* -- INTERNAL SETUP OF GEOMETRY --------------------------------------- */
/* -- stuff that can be cached -- */
-/* Cache of input to glDrawArrays */
+/* Cache of input to glDrawArrays or glDrawElements
+ * In general, we build arrays with all vertices or normals.
+ * We cant compress this and use glDrawElements as all combinations of
+ * vertex and normals are unique.
+ */
#define DECLARE_SHAPE_CACHE(name,nameICaps,nameCaps)\
static GLboolean name##Cached = FALSE;\
static GLdouble name##_verts[nameCaps##_VERT_ELEM_PER_OBJ];\
static GLboolean name##Cached = FALSE;\
static GLdouble name##_verts[nameCaps##_VERT_ELEM_PER_OBJ];\
static GLdouble name##_norms[nameCaps##_VERT_ELEM_PER_OBJ];\
- static GLboolean name##_edgeFlags[nameCaps##_VERT_PER_OBJ_TRI];\
+ static GLubyte name##_vertIdxs[nameCaps##_VERT_PER_OBJ_TRI];\
static void fgh##nameICaps##Generate()\
{\
- fghGenerateGeometryWithEdgeFlag(nameCaps##_NUM_FACES, nameCaps##_NUM_EDGE_PER_FACE,\
- name##_v, name##_vi, name##_n,\
- name##_verts, name##_norms, name##_edgeFlags);\
+ fghGenerateGeometryWithIndexArray(nameCaps##_NUM_FACES, nameCaps##_NUM_EDGE_PER_FACE,\
+ name##_v, name##_vi, name##_n,\
+ name##_verts, name##_norms, name##_vertIdxs);\
}
-/*
- * In general, we build arrays with all vertices or normals.
- * We cant compress this and use glDrawElements as all combinations of
- * vertex and normals are unique.
- */
/* -- Cube -- */
#define CUBE_NUM_VERT 8
#define CUBE_NUM_FACES 6
#define CUBE_NUM_EDGE_PER_FACE 4
#define CUBE_VERT_PER_OBJ (CUBE_NUM_FACES*CUBE_NUM_EDGE_PER_FACE)
+#define CUBE_VERT_ELEM_PER_OBJ (CUBE_VERT_PER_OBJ*3)
#define CUBE_VERT_PER_OBJ_TRI (CUBE_VERT_PER_OBJ+CUBE_NUM_FACES*2) /* 2 extra edges per face when drawing quads as triangles */
-#define CUBE_VERT_ELEM_PER_OBJ (CUBE_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble cube_v[CUBE_NUM_VERT*3] =
{
#define DODECAHEDRON_NUM_FACES 12
#define DODECAHEDRON_NUM_EDGE_PER_FACE 5
#define DODECAHEDRON_VERT_PER_OBJ (DODECAHEDRON_NUM_FACES*DODECAHEDRON_NUM_EDGE_PER_FACE)
+#define DODECAHEDRON_VERT_ELEM_PER_OBJ (DODECAHEDRON_VERT_PER_OBJ*3)
#define DODECAHEDRON_VERT_PER_OBJ_TRI (DODECAHEDRON_VERT_PER_OBJ+DODECAHEDRON_NUM_FACES*4) /* 4 extra edges per face when drawing pentagons as triangles */
-#define DODECAHEDRON_VERT_ELEM_PER_OBJ (DODECAHEDRON_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble dodecahedron_v[DODECAHEDRON_NUM_VERT*3] =
{
#define ICOSAHEDRON_NUM_FACES 20
#define ICOSAHEDRON_NUM_EDGE_PER_FACE 3
#define ICOSAHEDRON_VERT_PER_OBJ (ICOSAHEDRON_NUM_FACES*ICOSAHEDRON_NUM_EDGE_PER_FACE)
+#define ICOSAHEDRON_VERT_ELEM_PER_OBJ (ICOSAHEDRON_VERT_PER_OBJ*3)
#define ICOSAHEDRON_VERT_PER_OBJ_TRI ICOSAHEDRON_VERT_PER_OBJ
-#define ICOSAHEDRON_VERT_ELEM_PER_OBJ (ICOSAHEDRON_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble icosahedron_v[ICOSAHEDRON_NUM_VERT*3] =
{
#define OCTAHEDRON_NUM_FACES 8
#define OCTAHEDRON_NUM_EDGE_PER_FACE 3
#define OCTAHEDRON_VERT_PER_OBJ (OCTAHEDRON_NUM_FACES*OCTAHEDRON_NUM_EDGE_PER_FACE)
+#define OCTAHEDRON_VERT_ELEM_PER_OBJ (OCTAHEDRON_VERT_PER_OBJ*3)
#define OCTAHEDRON_VERT_PER_OBJ_TRI OCTAHEDRON_VERT_PER_OBJ
-#define OCTAHEDRON_VERT_ELEM_PER_OBJ (OCTAHEDRON_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble octahedron_v[OCTAHEDRON_NUM_VERT*3] =
#define RHOMBICDODECAHEDRON_NUM_FACES 12
#define RHOMBICDODECAHEDRON_NUM_EDGE_PER_FACE 4
#define RHOMBICDODECAHEDRON_VERT_PER_OBJ (RHOMBICDODECAHEDRON_NUM_FACES*RHOMBICDODECAHEDRON_NUM_EDGE_PER_FACE)
+#define RHOMBICDODECAHEDRON_VERT_ELEM_PER_OBJ (RHOMBICDODECAHEDRON_VERT_PER_OBJ*3)
#define RHOMBICDODECAHEDRON_VERT_PER_OBJ_TRI (RHOMBICDODECAHEDRON_VERT_PER_OBJ+RHOMBICDODECAHEDRON_NUM_FACES*2) /* 2 extra edges per face when drawing quads as triangles */
-#define RHOMBICDODECAHEDRON_VERT_ELEM_PER_OBJ (RHOMBICDODECAHEDRON_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble rhombicdodecahedron_v[RHOMBICDODECAHEDRON_NUM_VERT*3] =
#define TETRAHEDRON_NUM_FACES 4
#define TETRAHEDRON_NUM_EDGE_PER_FACE 3
#define TETRAHEDRON_VERT_PER_OBJ (TETRAHEDRON_NUM_FACES*TETRAHEDRON_NUM_EDGE_PER_FACE)
+#define TETRAHEDRON_VERT_ELEM_PER_OBJ (TETRAHEDRON_VERT_PER_OBJ*3)
#define TETRAHEDRON_VERT_PER_OBJ_TRI TETRAHEDRON_VERT_PER_OBJ
-#define TETRAHEDRON_VERT_ELEM_PER_OBJ (TETRAHEDRON_VERT_PER_OBJ_TRI*3)
/* Vertex Coordinates */
static GLdouble tetrahedron_v[TETRAHEDRON_NUM_VERT*3] =
/* -- 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
*
* Notes:
* It is the responsibility of the caller to free these tables
/* -- INTERNAL DRAWING functions --------------------------------------- */
-#define _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,edgeFlags)\
+#define _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,vertIdxs)\
static void fgh##nameICaps( GLboolean useWireMode )\
{\
if (!name##Cached)\
fgh##nameICaps##Generate();\
name##Cached = GL_TRUE;\
}\
- fghDrawGeometry(name##_verts,name##_norms,edgeFlags,\
- nameCaps##_VERT_PER_OBJ_TRI,nameCaps##_NUM_FACES,nameCaps##_NUM_EDGE_PER_FACE,\
- useWireMode);\
+ \
+ if (useWireMode)\
+ {\
+ fghDrawGeometryWire (name##_verts,name##_norms,\
+ nameCaps##_NUM_FACES,nameCaps##_NUM_EDGE_PER_FACE);\
+ }\
+ else\
+ {\
+ fghDrawGeometrySolid(name##_verts,name##_norms,vertIdxs,\
+ nameCaps##_VERT_PER_OBJ_TRI, nameCaps##_NUM_EDGE_PER_FACE);\
+ }\
}
-#define DECLARE_INTERNAL_DRAW(name,nameICaps,nameCaps) _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,NULL)
-#define DECLARE_INTERNAL_DRAW_DECOMPOSED_TO_TRIANGLE(name,nameICaps,nameCaps) _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,name##_edgeFlags)
+#define DECLARE_INTERNAL_DRAW(name,nameICaps,nameCaps) _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,NULL)
+#define DECLARE_INTERNAL_DRAW_DECOMPOSED_TO_TRIANGLE(name,nameICaps,nameCaps) _DECLARE_INTERNAL_DRAW_DO_DECLARE(name,nameICaps,nameCaps,name##_vertIdxs)
static void fghCube( GLdouble dSize, GLboolean useWireMode )
{
+ GLdouble *vertices;
+
if (!cubeCached)
{
fghCubeGenerate();
if (dSize!=1.)
{
+ /* Need to build new vertex list containing vertices for cube of different size */
int i;
- /* Need to build new vertex list containing vertices for cube of different size */
- GLdouble *vertices = malloc(CUBE_VERT_ELEM_PER_OBJ * sizeof(GLdouble));
+ vertices = malloc(CUBE_VERT_ELEM_PER_OBJ * sizeof(GLdouble));
+
/* Bail out if memory allocation fails, fgError never returns */
if (!vertices)
{
free(vertices);
fgError("Failed to allocate memory in fghCube");
}
+
for (i=0; i<CUBE_VERT_ELEM_PER_OBJ; i++)
vertices[i] = dSize*cube_verts[i];
+ }
+ else
+ vertices = cube_verts;
- fghDrawGeometry(vertices ,cube_norms,cube_edgeFlags,CUBE_VERT_PER_OBJ_TRI,CUBE_NUM_FACES,CUBE_NUM_EDGE_PER_FACE,useWireMode);
+ if (useWireMode)
+ fghDrawGeometryWire (vertices ,cube_norms, CUBE_NUM_FACES,CUBE_NUM_EDGE_PER_FACE);
+ else
+ fghDrawGeometrySolid(vertices ,cube_norms,cube_vertIdxs,CUBE_VERT_PER_OBJ_TRI, CUBE_NUM_EDGE_PER_FACE);
+ if (dSize!=1.)
/* cleanup allocated memory */
free(vertices);
- }
- else
- fghDrawGeometry(cube_verts,cube_norms,cube_edgeFlags,CUBE_VERT_PER_OBJ_TRI,CUBE_NUM_FACES,CUBE_NUM_EDGE_PER_FACE,useWireMode);
}
DECLARE_INTERNAL_DRAW_DECOMPOSED_TO_TRIANGLE(dodecahedron,Dodecahedron,DODECAHEDRON);
fghSierpinskiSpongeGenerate ( numLevels, offset, scale, vertices, normals );
/* Draw and cleanup */
- fghDrawGeometry(vertices,normals,NULL,numVert,numFace,TETRAHEDRON_NUM_EDGE_PER_FACE,useWireMode);
+ if (useWireMode)
+ fghDrawGeometryWire (vertices,normals, numFace,TETRAHEDRON_NUM_EDGE_PER_FACE);
+ else
+ fghDrawGeometrySolid(vertices,normals,NULL,numVert, TETRAHEDRON_NUM_EDGE_PER_FACE);
+
free(vertices);
free(normals );
}
projects / freeglut / commitdiff