voxeltronik/src/graphics/skybox.cpp

#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtx/transform.hpp>

#include "loadShader.h"

#include "graphics/skybox.h"
#include "graphics/glstate.h"

namespace vtk {

	Skybox::Skybox() {
		//xyzrgb
		float mVerts[] = {
			// front
			-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,   

			// back
			-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,

			// left
			-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,   

			// right
			 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,   

			// top
			-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,   

			// bottom
			-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
		};

		mShader = LoadShaders("res/shaders/skybox.vert", "res/shaders/skybox.frag");
		mViewMat = glGetUniformLocation(mShader, "view");
		mProjMat = glGetUniformLocation(mShader, "proj");

		glGenVertexArrays(1, &mVao);
		glBindVertexArray(mVao);
		glGenBuffers(1, &mVbo);
		glBindBuffer(GL_ARRAY_BUFFER, mVbo);
		glBufferData(GL_ARRAY_BUFFER, sizeof(mVerts), mVerts, GL_STATIC_DRAW);


		GLint posAttrib = glGetAttribLocation(mShader, "position");
		glEnableVertexAttribArray(posAttrib);
		glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 3*sizeof(float), 0);
	}

	void Skybox::draw(RenderTask& task) {
		auto camera = task.getCamera();
		camera.getViewMatrix();
		auto viewMat = camera.getAngleMatrix();
		auto pos = camera.getPosition();
		auto proj = camera.getProjectionMatrix();
	
		gls::setShader(mShader);	
		glUniformMatrix4fv(mViewMat, 1, GL_FALSE, glm::value_ptr(viewMat));
		glUniformMatrix4fv(mProjMat, 1, GL_FALSE, glm::value_ptr(proj));
		
		gls::setFlag(GL_DEPTH_TEST, false);
		glBindVertexArray(mVao);
		glDrawArrays(GL_TRIANGLES, 0, 36);
		gls::restoreState();
	}

}