Description
Setting up a skybox…
Change the Texture.h as follows
Add the following methods…
GLuint loadCubemap(std::vector<std::string> faces);
GLint getTexHandler() { return textureHandler; }
Addthe following method to the texture.cpp
GLuint Texture::loadCubemap(std::vector<std::string> faces)
{
glGenTextures(1, &textureHandler);
glBindTexture(GL_TEXTURE_CUBE_MAP, textureHandler);
int width, height, nrChannels;
for (unsigned int i = 0; i < faces.size(); i++)
{
unsigned char *data = stbi_load(faces[i].c_str(), &width, &height, &nrChannels, 0);
if (data)
{
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i,
0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data
);
stbi_image_free(data);
}
else
{
std::cout << “Cubemap texture failed to load at path: ” << faces[i] << std::endl;
stbi_image_free(data);
}
}
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
return textureHandler;
}
In the maingame.h add the following…
void Skybox();
GLuint skyboxVAO, skyboxVBO, cubemapTexture;
vector<std::string> faces;
Texture skybox;
Shader shaderSkybox;
In the maingame add the following to the init method…
vector<std::string> faces
{
“..\\res\\skybox\\right.jpg”,
“..\\res\\skybox\\left.jpg”,
“..\\res\\skybox\\top.jpg”,
“..\\res\\skybox\\bottom.jpg”,
“..\\res\\skybox\\front.jpg”,
“..\\res\\skybox\\back.jpg”
};
cubemapTexture = skybox.loadCubemap(faces); //Load the cubemap using “faces” into cubemapTextures
float skyboxVertices[] = {
// positions
-6.0f, 6.0f, -6.0f,
-6.0f, -6.0f, -6.0f,
6.0f, -6.0f, -6.0f,
6.0f, -6.0f, -6.0f,
6.0f, 6.0f, -6.0f,
-6.0f, 6.0f, -6.0f,
-6.0f, -6.0f, 6.0f,
-6.0f, -6.0f, -6.0f,
-6.0f, 6.0f, -6.0f,
-6.0f, 6.0f, -6.0f,
-6.0f, 6.0f, 6.0f,
-6.0f, -6.0f, 6.0f,
6.0f, -6.0f, -6.0f,
6.0f, -6.0f, 6.0f,
6.0f, 6.0f, 6.0f,
6.0f, 6.0f, 6.0f,
6.0f, 6.0f, -6.0f,
6.0f, -6.0f, -6.0f,
-6.0f, -6.0f, 6.0f,
-6.0f, 6.0f, 6.0f,
6.0f, 6.0f, 6.0f,
6.0f, 6.0f, 6.0f,
6.0f, -6.0f, 6.0f,
-6.0f, -6.0f, 6.0f,
-6.0f, 6.0f, -6.0f,
6.0f, 6.0f, -6.0f,
6.0f, 6.0f, 6.0f,
6.0f, 6.0f, 6.0f,
-6.0f, 6.0f, 6.0f,
-6.0f, 6.0f, -6.0f,
-6.0f, -6.0f, -6.0f,
-6.0f, -6.0f, 6.0f,
6.0f, -6.0f, -6.0f,
6.0f, -6.0f, -6.0f,
-6.0f, -6.0f, 6.0f,
6.0f, -6.0f, 6.0f
};
//use openGL functionality to generate & bind data into buffers
glGenVertexArrays(1, &skyboxVAO);
glGenBuffers(1, &skyboxVBO);
glBindVertexArray(skyboxVAO);
glBindBuffer(GL_ARRAY_BUFFER, skyboxVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), &skyboxVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
}
Add the following method…
void MainGame::Skybox()
{
glDepthFunc(GL_LEQUAL); // change depth function so depth test passes when values are equal to depth buffer’s content
shaderSkybox.Bind();
shaderSkybox.setInt(“skybox”, 0);
//view = glm::mat4(glm::mat3(camera.GetViewMatrix())); // remove translation from the view matrix
shaderSkybox.setMat4(“view”, myCamera.GetView());
shaderSkybox.setMat4(“projection”, myCamera.GetProjection());
// skybox cube
glBindVertexArray(skyboxVAO);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexture);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
glDepthFunc(GL_LESS); // set depth function back to default
}
TODO..
Initialise the skybox shader
Draw the skybox
Run the code,
