source: projectionDesigner/trunk/projdesigner/include/glm/glm.h @ 4

Last change on this file since 4 was 4, checked in by Torben Dannhauer, 14 years ago
File size: 10.0 KB
Line 
1/*   
2      glm.h
3      Nate Robins, 1997, 2000
4      nate@pobox.com, http://www.pobox.com/~nate
5 
6      Wavefront OBJ model file format reader/writer/manipulator.
7
8      Includes routines for generating smooth normals with
9      preservation of edges, welding redundant vertices & texture
10      coordinate generation (spheremap and planar projections) + more.
11
12 */
13#ifndef __GLM_H__
14#define __GLM_H__
15
16#ifdef __cplusplus
17extern "C" {
18#endif // __cplusplus
19
20#include <stdlib.h>
21#include <GL/glut.h>
22
23
24#ifndef M_PI
25#define M_PI 3.14159265f
26#endif
27
28#define GLM_NONE     (0)            /* render with only vertices */
29#define GLM_FLAT     (1 << 0)       /* render with facet normals */
30#define GLM_SMOOTH   (1 << 1)       /* render with vertex normals */
31#define GLM_TEXTURE  (1 << 2)       /* render with texture coords */
32#define GLM_COLOR    (1 << 3)       /* render with colors */
33#define GLM_MATERIAL (1 << 4)       /* render with materials */
34
35
36/* GLMmaterial: Structure that defines a material in a model.
37 */
38typedef struct _GLMmaterial
39{
40  char* name;                   /* name of material */
41  GLfloat diffuse[4];           /* diffuse component */
42  GLfloat ambient[4];           /* ambient component */
43  GLfloat specular[4];          /* specular component */
44  GLfloat emmissive[4];         /* emmissive component */
45  GLfloat shininess;            /* specular exponent */
46} GLMmaterial;
47
48/* GLMtriangle: Structure that defines a triangle in a model.
49 */
50typedef struct _GLMtriangle {
51  GLuint vindices[3];           /* array of triangle vertex indices */
52  GLuint nindices[3];           /* array of triangle normal indices */
53  GLuint tindices[3];           /* array of triangle texcoord indices*/
54  GLuint findex;                /* index of triangle facet normal */
55} GLMtriangle;
56
57/* GLMgroup: Structure that defines a group in a model.
58 */
59typedef struct _GLMgroup {
60  char*             name;           /* name of this group */
61  GLuint            numtriangles;   /* number of triangles in this group */
62  GLuint*           triangles;      /* array of triangle indices */
63  GLuint            material;       /* index to material for group */
64  struct _GLMgroup* next;           /* pointer to next group in model */
65} GLMgroup;
66
67/* GLMmodel: Structure that defines a model.
68 */
69typedef struct _GLMmodel {
70  char*    pathname;            /* path to this model */
71  char*    mtllibname;          /* name of the material library */
72
73  GLuint   numvertices;         /* number of vertices in model */
74  GLfloat* vertices;            /* array of vertices  */
75
76  GLuint   numnormals;          /* number of normals in model */
77  GLfloat* normals;             /* array of normals */
78
79  GLuint   numtexcoords;        /* number of texcoords in model */
80  GLfloat* texcoords;           /* array of texture coordinates */
81
82  GLuint   numfacetnorms;       /* number of facetnorms in model */
83  GLfloat* facetnorms;          /* array of facetnorms */
84
85  GLuint       numtriangles;    /* number of triangles in model */
86  GLMtriangle* triangles;       /* array of triangles */
87
88  GLuint       nummaterials;    /* number of materials in model */
89  GLMmaterial* materials;       /* array of materials */
90
91  GLuint       numgroups;       /* number of groups in model */
92  GLMgroup*    groups;          /* linked list of groups */
93
94  GLfloat position[3];          /* position of the model */
95
96} GLMmodel;
97
98
99/* glmUnitize: "unitize" a model by translating it to the origin and
100 * scaling it to fit in a unit cube around the origin.  Returns the
101 * scalefactor used.
102 *
103 * model - properly initialized GLMmodel structure
104 */
105GLfloat
106glmUnitize(GLMmodel* model);
107
108/* glmDimensions: Calculates the dimensions (width, height, depth) of
109 * a model.
110 *
111 * model      - initialized GLMmodel structure
112 * dimensions - array of 3 GLfloats (GLfloat dimensions[3])
113 */
114GLvoid
115glmDimensions(GLMmodel* model, GLfloat* dimensions);
116
117/* glmScale: Scales a model by a given amount.
118 *
119 * model - properly initialized GLMmodel structure
120 * scale - scalefactor (0.5 = half as large, 2.0 = twice as large)
121 */
122GLvoid
123glmScale(GLMmodel* model, GLfloat scale);
124
125/* glmReverseWinding: Reverse the polygon winding for all polygons in
126 * this model.  Default winding is counter-clockwise.  Also changes
127 * the direction of the normals.
128 *
129 * model - properly initialized GLMmodel structure
130 */
131GLvoid
132glmReverseWinding(GLMmodel* model);
133
134/* glmFacetNormals: Generates facet normals for a model (by taking the
135 * cross product of the two vectors derived from the sides of each
136 * triangle).  Assumes a counter-clockwise winding.
137 *
138 * model - initialized GLMmodel structure
139 */
140GLvoid
141glmFacetNormals(GLMmodel* model);
142
143/* glmVertexNormals: Generates smooth vertex normals for a model.
144 * First builds a list of all the triangles each vertex is in.  Then
145 * loops through each vertex in the the list averaging all the facet
146 * normals of the triangles each vertex is in.  Finally, sets the
147 * normal index in the triangle for the vertex to the generated smooth
148 * normal.  If the dot product of a facet normal and the facet normal
149 * associated with the first triangle in the list of triangles the
150 * current vertex is in is greater than the cosine of the angle
151 * parameter to the function, that facet normal is not added into the
152 * average normal calculation and the corresponding vertex is given
153 * the facet normal.  This tends to preserve hard edges.  The angle to
154 * use depends on the model, but 90 degrees is usually a good start.
155 *
156 * model - initialized GLMmodel structure
157 * angle - maximum angle (in degrees) to smooth across
158 */
159GLvoid
160glmVertexNormals(GLMmodel* model, GLfloat angle);
161
162/* glmLinearTexture: Generates texture coordinates according to a
163 * linear projection of the texture map.  It generates these by
164 * linearly mapping the vertices onto a square.
165 *
166 * model - pointer to initialized GLMmodel structure
167 */
168GLvoid
169glmLinearTexture(GLMmodel* model);
170
171/* glmSpheremapTexture: Generates texture coordinates according to a
172 * spherical projection of the texture map.  Sometimes referred to as
173 * spheremap, or reflection map texture coordinates.  It generates
174 * these by using the normal to calculate where that vertex would map
175 * onto a sphere.  Since it is impossible to map something flat
176 * perfectly onto something spherical, there is distortion at the
177 * poles.  This particular implementation causes the poles along the X
178 * axis to be distorted.
179 *
180 * model - pointer to initialized GLMmodel structure
181 */
182GLvoid
183glmSpheremapTexture(GLMmodel* model);
184
185/* glmDelete: Deletes a GLMmodel structure.
186 *
187 * model - initialized GLMmodel structure
188 */
189GLvoid
190glmDelete(GLMmodel* model);
191
192/* glmReadOBJ: Reads a model description from a Wavefront .OBJ file.
193 * Returns a pointer to the created object which should be free'd with
194 * glmDelete().
195 *
196 * filename - name of the file containing the Wavefront .OBJ format data. 
197 */
198GLMmodel* 
199glmReadOBJ(char* filename);
200
201/* glmWriteOBJ: Writes a model description in Wavefront .OBJ format to
202 * a file.
203 *
204 * model    - initialized GLMmodel structure
205 * filename - name of the file to write the Wavefront .OBJ format data to
206 * mode     - a bitwise or of values describing what is written to the file
207 *            GLM_NONE    -  write only vertices
208 *            GLM_FLAT    -  write facet normals
209 *            GLM_SMOOTH  -  write vertex normals
210 *            GLM_TEXTURE -  write texture coords
211 *            GLM_FLAT and GLM_SMOOTH should not both be specified.
212 */
213GLvoid
214glmWriteOBJ(GLMmodel* model, char* filename, GLuint mode);
215
216/* glmDraw: Renders the model to the current OpenGL context using the
217 * mode specified.
218 *
219 * model    - initialized GLMmodel structure
220 * mode     - a bitwise OR of values describing what is to be rendered.
221 *            GLM_NONE    -  render with only vertices
222 *            GLM_FLAT    -  render with facet normals
223 *            GLM_SMOOTH  -  render with vertex normals
224 *            GLM_TEXTURE -  render with texture coords
225 *            GLM_FLAT and GLM_SMOOTH should not both be specified.
226 */
227GLvoid
228glmDraw(GLMmodel* model, GLuint mode);
229
230/* glmList: Generates and returns a display list for the model using
231 * the mode specified.
232 *
233 * model    - initialized GLMmodel structure
234 * mode     - a bitwise OR of values describing what is to be rendered.
235 *            GLM_NONE    -  render with only vertices
236 *            GLM_FLAT    -  render with facet normals
237 *            GLM_SMOOTH  -  render with vertex normals
238 *            GLM_TEXTURE -  render with texture coords
239 *            GLM_FLAT and GLM_SMOOTH should not both be specified. 
240 */
241GLuint
242glmList(GLMmodel* model, GLuint mode);
243
244/* glmWeld: eliminate (weld) vectors that are within an epsilon of
245 * each other.
246 *
247 * model      - initialized GLMmodel structure
248 * epsilon    - maximum difference between vertices
249 *              ( 0.00001 is a good start for a unitized model)
250 *
251 */
252GLvoid
253glmWeld(GLMmodel* model, GLfloat epsilon);
254
255/* glmReadPPM: read a PPM raw (type P6) file.  The PPM file has a header
256 * that should look something like:
257 *
258 *    P6
259 *    # comment
260 *    width height max_value
261 *    rgbrgbrgb...
262 *
263 * where "P6" is the magic cookie which identifies the file type and
264 * should be the only characters on the first line followed by a
265 * carriage return.  Any line starting with a # mark will be treated
266 * as a comment and discarded.   After the magic cookie, three integer
267 * values are expected: width, height of the image and the maximum
268 * value for a pixel (max_value must be < 256 for PPM raw files).  The
269 * data section consists of width*height rgb triplets (one byte each)
270 * in binary format (i.e., such as that written with fwrite() or
271 * equivalent).
272 *
273 * The rgb data is returned as an array of unsigned chars (packed
274 * rgb).  The malloc()'d memory should be free()'d by the caller.  If
275 * an error occurs, an error message is sent to stderr and NULL is
276 * returned.
277 *
278 * filename   - name of the .ppm file.
279 * width      - will contain the width of the image on return.
280 * height     - will contain the height of the image on return.
281 *
282 */
283GLubyte* 
284glmReadPPM(char* filename, int* width, int* height);
285
286#ifdef __cplusplus
287}
288#endif // __cplusplus
289
290#endif // __GLM_H__
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