Opengl sampler2D和samplerCube在一个着色器中

我试图在一个着色器中使用

sampler2D

和

samplerCube

。我过去常常使用

struct

对一些

sampler2D

执行此操作。但是现在我决定不再把它们放在结构中，并且注意到了几个特性。如果我将

sampler2D

放入

struct

，绑定

samplerCube

一次就足够了。但是，如果我将

sampler2D

放在结构外部，每次绘制每个模型时，我都必须绑定

samplerCube

。下面我给出伪代码的示例

sampler2D

转换为

struct

：

uniform samplerCube shadowMaps;
uniform struct Mapping {
    sampler2D ambientMapping;
    sampler2D diffuseMapping;
    sampler2D specularMapping;
    sampler2D normalMapping;
} mapping;

uniform samplerCube shadowMaps;
uniform sampler2D ambientMapping;
uniform sampler2D diffuseMapping;
uniform sampler2D specularMapping;
uniform sampler2D normalMapping;

C++伪代码：

// somewhere in init
// samplerCube
glUniform1i(shadow, 4);
glActiveTexture(GL_TEXTURE4);
glBindTexture(GL_TEXTURE_CUBE_MAP, shadowMapId);

// ...

// drawing models
for (size_t i = 0; i < MODELS_COUNT; i++) {
    glUniform1i(model[i].ambientMapping, 0);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[0]);

    glUniform1i(model[i].diffuseMapping, 1);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[1]);
    // analogically for specular and normal

    // model
}

// drawing models
for (size_t i = 0; i < MODELS_COUNT; i++) {
    glUniform1i(model[i].ambientMapping, 0);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[0]);

    glUniform1i(model[i].diffuseMapping, 1);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[1]);
    // analogically for specular and normal

    // samplerCube
    glUniform1i(shadow, 4);
    glActiveTexture(GL_TEXTURE4);
    glBindTexture(GL_TEXTURE_CUBE_MAP, shadowMapId);

    // model
}

C++伪代码：

// somewhere in init
// samplerCube
glUniform1i(shadow, 4);
glActiveTexture(GL_TEXTURE4);
glBindTexture(GL_TEXTURE_CUBE_MAP, shadowMapId);

// ...

// drawing models
for (size_t i = 0; i < MODELS_COUNT; i++) {
    glUniform1i(model[i].ambientMapping, 0);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[0]);

    glUniform1i(model[i].diffuseMapping, 1);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[1]);
    // analogically for specular and normal

    // model
}

// drawing models
for (size_t i = 0; i < MODELS_COUNT; i++) {
    glUniform1i(model[i].ambientMapping, 0);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[0]);

    glUniform1i(model[i].diffuseMapping, 1);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, model[i].texturesIds[1]);
    // analogically for specular and normal

    // samplerCube
    glUniform1i(shadow, 4);
    glActiveTexture(GL_TEXTURE4);
    glBindTexture(GL_TEXTURE_CUBE_MAP, shadowMapId);

    // model
}

//绘图模型
对于（大小i=0；i

---

为什么在第二种情况下，我每次都要做

glBindTexture（GL\u TEXTURE\u CUBE\u MAP，shadowMapId）

？最好的方法是什么？什么更有效率？

所以您有“计数”

samplerCube

和4

sample2d

。但你似乎以相反的方式传递纹理单元。@Ripi2已编辑、删除

COUNT