lg_3d_primitives.h

/*
 *      LibGame - Copyright (C) Emmanuel Thomas-Maurin 2011-2026
 *      All rights reserved
 */
 
#ifndef LG_3D_PRIMITIVES_H
#define LG_3D_PRIMITIVES_H
 
/*
 * All vertices are Vertex_rgba
 * Could/should we implemenet the same with other vertex formats ?
 *
 * Check with:
 * INFO_OUT("MAX(MAX(QUAD_LINES3D_N_VERTICES, CUBOID_LINES3D_N_VERTICES), XYZ_ARROWS_LINES3D_N_VERTICES) = %d\n",
 *      MAX(MAX(QUAD_LINES3D_N_VERTICES, CUBOID_LINES3D_N_VERTICES), XYZ_ARROWS_LINES3D_N_VERTICES))
 * INFO_OUT("LINES3D_N_VERTICES_MAX = %d\n", LINES3D_N_VERTICES_MAX)
 */
 
#define QUAD_N_VERTICES                 4       /* Num of vertices of a quad */
#define QUAD_LINES3D_N_VERTICES         8       /* Num of vertices for all lines to draw a quad */
 
#define CUBOID_N_VERTICES               8       /* Num of vertices of a cuboid */
#define CUBOID_LINES3D_N_VERTICES       24      /* Num of vertices for all lines to draw a cuboid */
 
#define XYZ_ARROWS_LINES3D_N_VERTICES   18      /* Num of vertices for all lines to draw an xyz_arrows */
 
#define LINES3D_N_VERTICES_MAX          24      /* === Must be big enough, adjust as necessary === */
 
#if QUAD_LINES3D_N_VERTICES > LINES3D_N_VERTICES_MAX
  #error Sth is wrong with STH_LINES3D_N_VERTICES stuff
#elif CUBOID_LINES3D_N_VERTICES > LINES3D_N_VERTICES_MAX
  #error Sth is wrong with STH_LINES3D_N_VERTICES stuff
#elif XYZ_ARROWS_LINES3D_N_VERTICES > LINES3D_N_VERTICES_MAX
  #error Sth is wrong with STH_LINES3D_N_VERTICES stuff
#endif
 
/*
 * Generic 3D line set vertex buffer (Vertex_rgba)
 *
 * Useful for generating VBO from shapes - can have:
 * - an array of Vertex_rgba with array max size = LINES3D_N_VERTICES_MAX
 * or:
 * - a pointer to a bigger array (dynamically generated) of Vertex_rgba
 *
 *      Draw with glDrawArrays(GL_LINE, 0, n_vertices)
 *
 * Max num of lines = LINES3D_N_VERTICES_MAX / 2
 *
 * The vertex buffer is either a *static* one (static array) or a *dynamic* one (malloc3() generated)
 * You can/should access it using sth like:
 *      buffer = dynamic_b ? vb_ptr : vb_array
 */
typedef struct {
        Vertex_rgba             vb_array[LINES3D_N_VERTICES_MAX];
        union {
                Vertex_rgba     *vb_ptr;
                uint64_t        unused;         /* To fix serialization bug on 32-bit arch */
        };
        uint32_t                n_vertices;
        zboolean                dynamic_b;
} Lines3D_VB;
 
typedef struct {
        Vertex_rgba     vertex[QUAD_N_VERTICES];
} LG_Quad;
 
typedef struct {
        Vertex_rgba     vertex[CUBOID_N_VERTICES];
} LG_Cuboid;
 
typedef struct {
        Vertex_rgba     vertex[XYZ_ARROWS_LINES3D_N_VERTICES];
} XYZ_Arrows;
 
LG_Quad                 lg_quad(vec3_t, vec3_t, vec3_t, vec3_t, LG_Color_u);
 
LG_Quad                 lg_centered_unit_quad(LG_Color_u);
 
LG_Quad                 lg_quad_transform(LG_Quad, mat4_t);
 
LG_Cuboid               lg_cuboid(vec3_t, vec3_t, vec3_t, vec3_t, vec3_t, vec3_t, vec3_t, vec3_t, LG_Color_u);
 
zboolean                lg_shape_is_cuboid(LG_Cuboid *);
 
LG_Cuboid               lg_centered_unit_cube(LG_Color_u);
 
LG_Cuboid               lg_cuboid_transform(LG_Cuboid, mat4_t);
 
XYZ_Arrows              lg_xyz_arrows_LH(float, LG_Color_u, LG_Color_u, LG_Color_u);
 
XYZ_Arrows              lg_xyz_arrows_RH(float, LG_Color_u, LG_Color_u, LG_Color_u);
 
Lines3D_VB              lg_l3d_vb_from_quad(LG_Quad);
 
Lines3D_VB              lg_l3d_vb_from_cuboid(LG_Cuboid);
 
Lines3D_VB              lg_l3d_vb_from_arrows(XYZ_Arrows);
 
vec3_t                  vec3_LH_to_RH(vec3_t);
 
vec3_t                  vec3_RH_to_LH(vec3_t);
 
/* (all Vertex_rgba until here) */
 
/* MOSTLY DEPRECATED - should cleanup/reorganize/rewrite some of following stuff, which is a bit of a mess */
 
const Vertex_uv         *lg_cube_normalized_vertices_uv();
 
const unsigned short    *lg_cube_vertex_uv_indices();
 
size_t                  lg_sizeof_cube_normalized_vertices_uv();
 
size_t                  lg_sizeof_cube_vertex_uv_indices();
 
const Vertex_rgba       *lg_cube_normalized_vertices_rgba();
 
const unsigned short    *lg_wired_cube_vertex_rgba_indices();
 
size_t                  lg_sizeof_cube_normalized_vertices_rgba();
 
size_t                  lg_sizeof_wired_cube_vertex_rgba_indices();
 
#endif /* LG_3D_PRIMITIVES_H */