Skybox.cpp

#include "Skybox.h"

#define CUBE_TEXTURE_SIZE 800

Skybox::Skybox()
{
	modelMat = glm::mat4();
}

GLuint Skybox::getID()
{
	return textureID;
}

void Skybox::render()
{
	glBindVertexArray(VAO);
	glDrawArrays(GL_TRIANGLES, 0, 36);
	glBindVertexArray(0);
}

bool Skybox::loadCubeMap(std::vector<const GLchar*> faces)
{
	glGenTextures(1, &textureID);

	int width, height;
	unsigned char* image;

	glBindTexture(GL_TEXTURE_CUBE_MAP, this->textureID);
	for (GLuint i = 0; i < faces.size(); i++)
	{
		image = SOIL_load_image(faces[i], &width, &height, 0, SOIL_LOAD_RGB);
		if (image == NULL) {
			std::cout << "Unable to open skybox texture" << std::endl;
			return false;
		}
		glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
		SOIL_free_image_data(image);
	}
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_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);
	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

	return true;
}

void Skybox::buildCubeMesh()
{
	GLfloat vertices[] = {         
		-1.0f,  1.0f, -1.0f,
		-1.0f, -1.0f, -1.0f,
		1.0f, -1.0f, -1.0f,
		1.0f, -1.0f, -1.0f,
		1.0f,  1.0f, -1.0f,
		-1.0f,  1.0f, -1.0f,

		-1.0f, -1.0f,  1.0f,
		-1.0f, -1.0f, -1.0f,
		-1.0f,  1.0f, -1.0f,
		-1.0f,  1.0f, -1.0f,
		-1.0f,  1.0f,  1.0f,
		-1.0f, -1.0f,  1.0f,

		1.0f, -1.0f, -1.0f,
		1.0f, -1.0f,  1.0f,
		1.0f,  1.0f,  1.0f,
		1.0f,  1.0f,  1.0f,
		1.0f,  1.0f, -1.0f,
		1.0f, -1.0f, -1.0f,

		-1.0f, -1.0f,  1.0f,
		-1.0f,  1.0f,  1.0f,
		1.0f,  1.0f,  1.0f,
		1.0f,  1.0f,  1.0f,
		1.0f, -1.0f,  1.0f,
		-1.0f, -1.0f,  1.0f,

		-1.0f,  1.0f, -1.0f,
		1.0f,  1.0f, -1.0f,
		1.0f,  1.0f,  1.0f,
		1.0f,  1.0f,  1.0f,
		-1.0f,  1.0f,  1.0f,
		-1.0f,  1.0f, -1.0f,

		-1.0f, -1.0f, -1.0f,
		-1.0f, -1.0f,  1.0f,
		1.0f, -1.0f, -1.0f,
		1.0f, -1.0f, -1.0f,
		-1.0f, -1.0f,  1.0f,
		1.0f, -1.0f,  1.0f
	};

	glGenVertexArrays(1, &VAO);
	glGenBuffers(1, &VBO);
	glBindVertexArray(VAO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), &vertices, GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
	glBindVertexArray(0);
}