math.c

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/* This code is (C) AllegroGL contributors, and double licensed under
 * the GPL and zlib licenses. See gpl.txt or zlib.txt for details.
 */
#include <math.h>
#include <allegro.h>
#include "alleggl.h"
#include "allglint.h"


#ifndef M_PI
   #define M_PI   3.14159265358979323846
#endif


#define ALGL_NOCONV(x) x

#define TRANSLATE_AL_TO_GL(al_type, gl_type, convertor) \
    void allegro_gl_##al_type##_to_##gl_type (al_type *m, gl_type gl[16]) \
    { \
        int col, row; \
        for (col = 0; col < 3; col++) \
            for (row = 0; row < 3; row++) \
                gl[col*4+row] = convertor (m->v[col][row]); \
        for (row = 0; row < 3; row++) \
            gl[12+row] = convertor (m->t[row]); \
        for (col = 0; col < 3; col++) \
            gl[4*col + 3] = 0; \
        gl[15] = 1; \
    }



TRANSLATE_AL_TO_GL(MATRIX, GLfloat, fixtof)


    

TRANSLATE_AL_TO_GL(MATRIX, GLdouble, fixtof)

    

TRANSLATE_AL_TO_GL(MATRIX_f, GLfloat, ALGL_NOCONV)



TRANSLATE_AL_TO_GL(MATRIX_f, GLdouble, ALGL_NOCONV)


    
#define TRANSLATE_GL_TO_AL(gl_type, al_type, convertor) \
    void allegro_gl_##gl_type##_to_##al_type (gl_type gl[16], al_type *m) \
    { \
        int col, row; \
        for (col = 0; col < 3; col++) \
            for (row = 0; row < 3; row++) \
                m->v[col][row] = convertor (gl[col*4+row]); \
        for (row = 0; row < 3; row++) \
            m->t[row] = convertor (gl[12+row]); \
    }



TRANSLATE_GL_TO_AL(GLfloat, MATRIX, ftofix)




TRANSLATE_GL_TO_AL(GLdouble, MATRIX, ftofix)



TRANSLATE_GL_TO_AL(GLfloat, MATRIX_f, ALGL_NOCONV)

    

TRANSLATE_GL_TO_AL(GLdouble, MATRIX_f, ALGL_NOCONV)


#undef ALGL_NOCONV


#ifndef RAD_2_DEG
    #define RAD_2_DEG(a) ((a) * 180 / M_PI)
#endif

    

/* void allegro_gl_apply_quat(QUAT *q) */
void allegro_gl_apply_quat(QUAT *q) {

    float theta;
    ASSERT(q);
    ASSERT(__allegro_gl_valid_context);

    theta = RAD_2_DEG(2 * acos(q->w));
    if (q->w < 1.0f && q->w > -1.0f) 
        glRotatef(theta, q->x, q->y, q->z); 

    return;
}



/* void allegro_gl_quat_to_glrotatef(QUAT *q, float *angle, float *x, float *y, float *z) */
void allegro_gl_quat_to_glrotatef(QUAT *q, float *angle, float *x, float *y, float *z) {

    ASSERT(q);
    ASSERT(angle);
    ASSERT(x);
    ASSERT(y);
    ASSERT(z);

    *angle = RAD_2_DEG(2 * acos(q->w));
    *x = q->x;
    *y = q->y;
    *z = q->z;

    return;
}



/* void allegro_gl_quat_to_glrotated(QUAT *q, double *angle, double *x, double *y, double *z) */
void allegro_gl_quat_to_glrotated(QUAT *q, double *angle, double *x, double *y, double *z) {

    ASSERT(q);
    ASSERT(angle);
    ASSERT(x);
    ASSERT(y);
    ASSERT(z);

    *angle = RAD_2_DEG(2 * acos(q->w));
    *x = q->x;
    *y = q->y;
    *z = q->z;

    return;
}