# Struct API

Struct API is alternative API to array api to use cglm with improved type safety and easy to use. Since struct api is built top of array api, every struct API is not documented here. See array api documentation for more information for individual functions.

By default struct api adds s suffix to every type name e.g. vec3s, mat4s, versors etc. Also struct api s suffix to namespace e.g. glms_vec3_add, glms_mat4_mul etc.

By starting v0.9.0, struct api namespace is configurable. We can omit glms_ namespace or even change it with custom name to move existing api integrations to cglm more easily… We can also add s to function names if we want e.g. glms_vec3_add() -> vec3_add() or vec3s_add().

By including cglm/struct.h header you will include all struct api. It will also include cglm/cglm.h too. Since struct apis are inline you don’t need to build or link cglm against your project unless if you want to use pre-built call-api too.

Struct API is built top of array api. So you can mix them. Use .raw union member to access raw array data to use it with array api.

Unlike array api ([0], [1], [0][0] …), it is also possible to use struct api with .x, .y, .z, .w, .r, .g, .b, .a, .m00, m01… accessors to access individual elements/properties of vectors and matrices.

## Struct API usage:

    #include <cglm/struct.h>

    mat4s m1  = glms_mat4_identity(); /* init...  */
    mat4s m2  = glms_mat4_identity(); /* init...  */
    mat4s m3  = glms_mat4_mul(glms_mat4_mul(m1, m2), glms_mat4_mul(m3, m4));

    vec3s v1  = { 1.0f, 0.0f, 0.0f };
    vec3s v2  = { 0.0f, 1.0f, 0.0f };
    vec4s v4  = { 0.0f, 1.0f, 0.0f, 0.0f };
    vec4  v5a = { 0.0f, 1.0f, 0.0f, 0.0f };

    mat4s m4 = glms_rotate(m3, M_PI_2,
                           glms_vec3_cross(glms_vec3_add(v1, v6)
                                           glms_vec3_add(v1, v7)));

    v1.x = 1.0f; v1.y = 0.0f; v1.z = 0.0f;
    // or
    v1.raw[0] = 1.0f; v1.raw[1] = 0.0f; v1.raw[2] = 0.0f;

    /* use struct api with array api (mix them). */
    /* use .raw to access array and use it with array api */

    glm_vec4_add(m4.col[0].raw, v5a, m4.col[0].raw);
    glm_mat4_mulv(m4.raw, v4.raw, v5a);

or omit glms_ namespace completely (see options below):

    #define CGLM_OMIT_NS_FROM_STRUCT_API

    #include <cglm/struct.h>

    mat4s m1  = mat4_identity(); /* init...  */
    mat4s m2  = mat4_identity(); /* init...  */
    mat4s m3  = mat4_mul(mat4_mul(m1, m2), mat4_mul(m3, m4));

    vec3s v1  = { 1.0f, 0.0f, 0.0f };
    vec3s v2  = { 0.0f, 1.0f, 0.0f };
    vec4s v4  = { 0.0f, 1.0f, 0.0f, 0.0f };
    vec4  v5a = { 0.0f, 1.0f, 0.0f, 0.0f };

    mat4s m4 = glms_rotate(m3, M_PI_2,
                           vec3_cross(vec3_add(v1, v6)
                                      vec3_add(v1, v7)));

    v1.x = 1.0f; v1.y = 0.0f; v1.z = 0.0f;
    // or
    v1.raw[0] = 1.0f; v1.raw[1] = 0.0f; v1.raw[2] = 0.0f;

    /* use struct api with array api (mix them) */
    glm_vec4_add(m4.col[0].raw, v5a, m4.col[0].raw);
    glm_mat4_mulv(m4.raw, v4.raw, v5a);

### Configuring the Struct API:

To configure the Struct API namespace, you can define the following macros before including the cglm/struct.h header:

- CGLM_OMIT_NS_FROM_STRUCT_API: omits CGLM_STRUCT_API_NS (glms_) namespace completely if there is sub namespace e.g mat4_, vec4_ … DEFAULT is not defined

- CGLM_STRUCT_API_NS: define name space for struct api, DEFAULT is glms

- CGLM_STRUCT_API_NAME_SUFFIX: define name suffix, DEFAULT is empty e.g defining it as #define CGLM_STRUCT_API_NAME_SUFFIX s will add s suffix to mat4_mul -> mat4s_mul

❗️ IMPORTANT ❗️

It’s a good idea to set up your config macros in build settings like CMake, Xcode, or Visual Studio. This is especially important if you’re using features like Modules in Xcode, where adding macros directly before the cglm headers might not work.

### Detailed documentation for Struct API:

Since struct api if built top of array api, see array api functions for more information about individual functions.