glsl - 如何在 GLSL 结构体中初始化数组

Question

我尝试在结构内初始化数组，如下所示:

struct myStruct {

  vec3 data[20] = vec3[20] (vec3(1, 1,  1), vec3( 1, -1,  1), vec3(-1, -1,  1), vec3(-1, 1,  1),
                            vec3(1, 1, -1), vec3( 1, -1, -1), vec3(-1, -1, -1), vec3(-1, 1, -1),
                            vec3(1, 1,  0), vec3( 1, -1,  0), vec3(-1, -1,  0), vec3(-1, 1,  0),
                            vec3(1, 0,  1), vec3(-1,  0,  1), vec3( 1,  0, -1), vec3(-1, 0, -1),
                            vec3(0, 1,  1), vec3( 0, -1,  1), vec3( 0, -1, -1), vec3( 0, 1, -1));

};

但我收到此错误:

ERROR: 0:84: '=' : syntax error: syntax error

可以这样做吗？

Answer 1

struct 启动类型规范，而不是变量声明。您必须声明一个变量并使用结构构造函数(请参阅 Data Type (GLSL) - Struct constructors ):

struct myStruct {
    vec3 data[20];
};

myStruct myVar = myStruct( vec3[20]( vec3(1, 1,  1), ..... ) );

请参阅GLSL Specification - 4.1.8 Structures

User-defined types can be created by aggregating other already defined types into a structure using the struct keyword. For example,

struct keyword. For example,
    struct light {
    float intensity;
    vec3 position;
} lightVar;

Structures can be initialized at declaration time using constructors, as discussed in section 5.4.3 “Structure Constructors”

请参阅GLSL Specification - 5.4.3 Structure Constructors

Once a structure is defined, and its type is given a name, a constructor is available with the same name to construct instances of that structure. For example:

struct light {
    float intensity;
    vec3 position;
};
light lightVar = light(3.0, vec3(1.0, 2.0, 3.0));