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/*
* GLM library. Wavefront .obj file format reader/writer/manipulator.
*
* Written by Nate Robins, 1997.
* email: ndr@pobox.com
* www: http://www.pobox.com/~ndr
*/
#ifndef GLM_H
#define GLM_H
typedef unsigned int uint;
#ifndef M_PI
#define M_PI 3.14159265
#endif
/* defines */
#define GLM_NONE (0) /* render with only vertices */
#define GLM_FLAT (1 << 0) /* render with facet normals */
#define GLM_SMOOTH (1 << 1) /* render with vertex normals */
#define GLM_TEXTURE (1 << 2) /* render with texture coords */
#define GLM_COLOR (1 << 3) /* render with colors */
#define GLM_MATERIAL (1 << 4) /* render with materials */
/* structs */
/* GLMmaterial: Structure that defines a material in a model.
*/
typedef struct _GLMmaterial
{
char* name; /* name of material */
float diffuse[4]; /* diffuse component */
float ambient[4]; /* ambient component */
float specular[4]; /* specular component */
float emmissive[4]; /* emmissive component */
float shininess; /* specular exponent */
char *map_kd; /* diffuse texture map file */
uint texture_kd; /* diffuse texture map */
uint texture_ks; /* specular texture map */
int uDiffuse, uAmbient, uSpecular, uShininess, uDiffTex, uSpecTex;
uint prog;
} GLMmaterial;
/* GLMtriangle: Structure that defines a triangle in a model.
*/
typedef struct {
uint vindices[3]; /* array of triangle vertex indices */
uint nindices[3]; /* array of triangle normal indices */
uint tindices[3]; /* array of triangle texcoord indices*/
uint findex; /* index of triangle facet normal */
} GLMtriangle;
/* GLMgroup: Structure that defines a group in a model.
*/
typedef struct _GLMgroup {
char* name; /* name of this group */
uint numtriangles; /* number of triangles in this group */
uint* triangles; /* array of triangle indices */
uint material; /* index to material for group */
uint * triIndexes;
uint minIndex, maxIndex;
struct _GLMgroup* next; /* pointer to next group in model */
} GLMgroup;
/* GLMmodel: Structure that defines a model.
*/
typedef struct {
char* pathname; /* path to this model */
char* mtllibname; /* name of the material library */
uint numvertices; /* number of vertices in model */
float* vertices; /* array of vertices */
uint numnormals; /* number of normals in model */
float* normals; /* array of normals */
uint numtexcoords; /* number of texcoords in model */
float* texcoords; /* array of texture coordinates */
uint numfacetnorms; /* number of facetnorms in model */
float* facetnorms; /* array of facetnorms */
uint numtriangles; /* number of triangles in model */
GLMtriangle* triangles; /* array of triangles */
uint nummaterials; /* number of materials in model */
GLMmaterial* materials; /* array of materials */
uint numgroups; /* number of groups in model */
GLMgroup* groups; /* linked list of groups */
float position[3]; /* position of the model */
float scale;
uint vbo; /* OpenGL VBO for vertex data */
uint vertexSize; /* number of floats per vertex */
uint posOffset; /* offset of position within vertex, in bytes */
uint normOffset; /* offset of normal within vertex, in bytes */
uint texOffset; /* offset of texcoord within vertex, in bytes */
} GLMmodel;
/* public functions */
/* glmUnitize: "unitize" a model by translating it to the origin and
* scaling it to fit in a unit cube around the origin. Returns the
* scalefactor used.
*
* model - properly initialized GLMmodel structure
*/
float
glmUnitize(GLMmodel* model);
/* glmDimensions: Calculates the dimensions (width, height, depth) of
* a model.
*
* model - initialized GLMmodel structure
* dimensions - array of 3 floats (float dimensions[3])
*/
void
glmDimensions(GLMmodel* model, float* dimensions);
/* glmScale: Scales a model by a given amount.
*
* model - properly initialized GLMmodel structure
* scale - scalefactor (0.5 = half as large, 2.0 = twice as large)
*/
void
glmScale(GLMmodel* model, float scale);
/* glmReverseWinding: Reverse the polygon winding for all polygons in
* this model. Default winding is counter-clockwise. Also changes
* the direction of the normals.
*
* model - properly initialized GLMmodel structure
*/
void
glmReverseWinding(GLMmodel* model);
/* glmFacetNormals: Generates facet normals for a model (by taking the
* cross product of the two vectors derived from the sides of each
* triangle). Assumes a counter-clockwise winding.
*
* model - initialized GLMmodel structure
*/
void
glmFacetNormals(GLMmodel* model);
/* glmVertexNormals: Generates smooth vertex normals for a model.
* First builds a list of all the triangles each vertex is in. Then
* loops through each vertex in the the list averaging all the facet
* normals of the triangles each vertex is in. Finally, sets the
* normal index in the triangle for the vertex to the generated smooth
* normal. If the dot product of a facet normal and the facet normal
* associated with the first triangle in the list of triangles the
* current vertex is in is greater than the cosine of the angle
* parameter to the function, that facet normal is not added into the
* average normal calculation and the corresponding vertex is given
* the facet normal. This tends to preserve hard edges. The angle to
* use depends on the model, but 90 degrees is usually a good start.
*
* model - initialized GLMmodel structure
* angle - maximum angle (in degrees) to smooth across
*/
void
glmVertexNormals(GLMmodel* model, float angle);
/* glmLinearTexture: Generates texture coordinates according to a
* linear projection of the texture map. It generates these by
* linearly mapping the vertices onto a square.
*
* model - pointer to initialized GLMmodel structure
*/
void
glmLinearTexture(GLMmodel* model);
/* glmSpheremapTexture: Generates texture coordinates according to a
* spherical projection of the texture map. Sometimes referred to as
* spheremap, or reflection map texture coordinates. It generates
* these by using the normal to calculate where that vertex would map
* onto a sphere. Since it is impossible to map something flat
* perfectly onto something spherical, there is distortion at the
* poles. This particular implementation causes the poles along the X
* axis to be distorted.
*
* model - pointer to initialized GLMmodel structure
*/
void
glmSpheremapTexture(GLMmodel* model);
/* glmDelete: Deletes a GLMmodel structure.
*
* model - initialized GLMmodel structure
*/
void
glmDelete(GLMmodel* model);
/* glmReadOBJ: Reads a model description from a Wavefront .OBJ file.
* Returns a pointer to the created object which should be free'd with
* glmDelete().
*
* filename - name of the file containing the Wavefront .OBJ format data.
*/
GLMmodel*
glmReadOBJ(char* filename);
/* glmWriteOBJ: Writes a model description in Wavefront .OBJ format to
* a file.
*
* model - initialized GLMmodel structure
* filename - name of the file to write the Wavefront .OBJ format data to
* mode - a bitwise or of values describing what is written to the file
* GLM_NONE - write only vertices
* GLM_FLAT - write facet normals
* GLM_SMOOTH - write vertex normals
* GLM_TEXTURE - write texture coords
* GLM_FLAT and GLM_SMOOTH should not both be specified.
*/
void
glmWriteOBJ(GLMmodel* model, char* filename, uint mode);
/* glmDraw: Renders the model to the current OpenGL context using the
* mode specified.
*
* model - initialized GLMmodel structure
* mode - a bitwise OR of values describing what is to be rendered.
* GLM_NONE - render with only vertices
* GLM_FLAT - render with facet normals
* GLM_SMOOTH - render with vertex normals
* GLM_TEXTURE - render with texture coords
* GLM_FLAT and GLM_SMOOTH should not both be specified.
*/
void
glmDraw(GLMmodel* model, uint mode);
/* glmList: Generates and returns a display list for the model using
* the mode specified.
*
* model - initialized GLMmodel structure
* mode - a bitwise OR of values describing what is to be rendered.
* GLM_NONE - render with only vertices
* GLM_FLAT - render with facet normals
* GLM_SMOOTH - render with vertex normals
* GLM_TEXTURE - render with texture coords
* GLM_FLAT and GLM_SMOOTH should not both be specified.
*/
uint
glmList(GLMmodel* model, uint mode);
/* glmWeld: eliminate (weld) vectors that are within an epsilon of
* each other.
*
* model - initialized GLMmodel structure
* epsilon - maximum difference between vertices
* ( 0.00001 is a good start for a unitized model)
*
*/
void
glmWeld(GLMmodel* model, float epsilon);
void
glmReIndex(GLMmodel *model);
void
glmMakeVBOs(GLMmodel *model);
void
glmDrawVBO(GLMmodel *model);
void
glmPrint(const GLMmodel *model);
void
glmShaderMaterial(GLMmaterial *mat);
void
glmLoadTextures(GLMmodel *model);
void
glmSpecularTexture(GLMmodel *model, uint cubeTex);
#endif /* GLM_H */
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