forkkmuopengl/BaseGLProject/ColorCube.cpp

#include "ColorCube.h"

glm::vec3 computeNormal(glm::vec3 p1, glm::vec3 p2, glm::vec3 p3)
{
	glm::vec3 v1 = p2 - p1;
	glm::vec3 v2 = p3 - p1;

	return glm::normalize(glm::cross(v1, v2));
}

void ColorCube::iboSetup()
{
	std::vector<glm::vec3> cube_vertices =
	{ { -1.0, -1.0, 1.0},
	{ 1.0, -1.0, 1.0},
	{ 1.0, 1.0, 1.0},
	{ -1.0, 1.0, 1.0},		
	{ -1.0, -1.0, -1.0},
	{ 1.0, -1.0, -1.0},
	{ 1.0, 1.0, -1.0},
	{ -1.0, 1.0, -1.0} };	

	GLfloat cube_colors[] = {
		// front colors
		1.0, 0.0, 0.0,
		0.0, 1.0, 0.0,
		0.0, 0.0, 1.0,
		1.0, 1.0, 1.0,
		// back colors
		1.0, 0.0, 0.0,
		0.0, 1.0, 0.0,
		0.0, 0.0, 1.0,
		1.0, 1.0, 1.0,
	};

	GLushort cube_elements[] = {
		0, 1, 2,		2, 3, 0,		1, 5, 6,
		6, 2, 1,		7, 6, 5,		5, 4, 7,
		4, 0, 3,		3, 7, 4,		4, 5, 1,
		1, 0, 4,		3, 2, 6,		6, 7, 3,
	};
	

	glGenVertexArrays(1, &_vaoHandle);
	glBindVertexArray(_vaoHandle);

	glGenBuffers(1, &_vbo_vertices);
	glBindBuffer(GL_ARRAY_BUFFER, _vbo_vertices);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * cube_vertices.size() * 3, cube_vertices.data(), GL_STATIC_DRAW);

	glVertexAttribPointer(
		0,   //attr number = 0
		3,
		GL_FLOAT, 
		GL_FALSE,
		0,
		(void*)0);
	glEnableVertexAttribArray(0);  //attr number = 0

	glGenBuffers(1, &_vbo_colors);
	glBindBuffer(GL_ARRAY_BUFFER, _vbo_colors);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 24, cube_colors, GL_STATIC_DRAW);

	glVertexAttribPointer(
		1,
		3,
		GL_FLOAT,
		GL_FALSE,
		0,
		(void*)0);
	glEnableVertexAttribArray(1);

	glGenBuffers(1, &_iboHandle);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _iboHandle);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(cube_elements), cube_elements, GL_STATIC_DRAW);

	glBindVertexArray(0);
}

void ColorCube::vaoSetup()
{	
	std::vector<glm::vec3> cube_vertices = 
		{ { -1.0, -1.0, 1.0}, { 1.0, -1.0, 1.0}, { 1.0, 1.0, 1.0},
		{ 1.0, 1.0, 1.0}, { -1.0, 1.0, 1.0}, { -1.0, -1.0, 1.0},
		{ 1.0, -1.0, 1.0}, { 1.0, -1.0, -1.0}, { 1.0, 1.0, -1.0},
		{ 1.0, 1.0, -1.0}, { 1.0, 1.0, 1.0}, { 1.0, -1.0, 1.0},
		{ -1.0, 1.0, -1.0}, { 1.0, 1.0, -1.0}, { 1.0, -1.0, -1.0},
		{ 1.0, -1.0, -1.0}, { -1.0, -1.0, -1.0}, { -1.0, 1.0, -1.0},
		{ -1.0, -1.0, -1.0}, { -1.0, -1.0, 1.0}, { -1.0, 1.0, 1.0},
		{ -1.0, 1.0, 1.0}, { -1.0, 1.0, -1.0},  { -1.0, -1.0, -1.0},
		{ -1.0, -1.0, -1.0}, { 1.0, -1.0, -1.0}, { 1.0, -1.0, 1.0},
		{ 1.0, -1.0, 1.0}, { -1.0, -1.0, 1.0}, { -1.0, -1.0, -1.0},
		{ -1.0, 1.0, 1.0}, { 1.0, 1.0, 1.0}, { 1.0, 1.0, -1.0},
		{ 1.0, 1.0, -1.0}, { -1.0, 1.0, -1.0}, { -1.0, 1.0, 1.0} };

	std::vector<GLfloat> cube_colors = {
		1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0,
		0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0,
		0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0,
		0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0,
		1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0,
		0.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0,
		1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0,
		1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0,
		1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
		0.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0,
		1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0,
		0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
	};
	
	std::vector<glm::vec3> cube_normals;

	for (int i = 0; i < cube_vertices.size() - 2; i += 3)
	{
		glm::vec3 norm = computeNormal(
			cube_vertices[i], cube_vertices[i + 1], cube_vertices[i + 2]);
		cube_normals.push_back(norm); cube_normals.push_back(norm); cube_normals.push_back(norm);
	}


	glGenVertexArrays(1, &_vaoHandle);
	glBindVertexArray(_vaoHandle);

	glGenBuffers(1, &_vbo_vertices);
	glBindBuffer(GL_ARRAY_BUFFER, _vbo_vertices);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * cube_vertices.size() * 3, cube_vertices.data(), GL_STATIC_DRAW);

	glVertexAttribPointer(
		0,   //attr number = 0
		3,
		GL_FLOAT,
		GL_FALSE,
		0,
		(void*)0);
	glEnableVertexAttribArray(0);  //attr number = 0

	glGenBuffers(1, &_vbo_normals);
	glBindBuffer(GL_ARRAY_BUFFER, _vbo_normals);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * cube_normals.size() * 3, cube_normals.data(), GL_STATIC_DRAW);

	glVertexAttribPointer(
		1,
		3,
		GL_FLOAT,
		GL_FALSE,
		0,
		(void*)0);
	glEnableVertexAttribArray(1);

	glGenBuffers(1, &_vbo_colors);
	glBindBuffer(GL_ARRAY_BUFFER, _vbo_colors);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * cube_colors.size(), cube_colors.data(), GL_STATIC_DRAW);

	glVertexAttribPointer(
		2,
		3,
		GL_FLOAT,
		GL_FALSE,
		0,
		(void*)0);
	glEnableVertexAttribArray(2);

	glBindVertexArray(0);
}

ColorCube::ColorCube(bool usingIBO)
{
	ibo_used = usingIBO;
	if (usingIBO)
		iboSetup();
	else
		vaoSetup();
}


void ColorCube::draw(ShaderProgram *shader, glm::mat4x4 proj_matrix, glm::mat4x4 view_matrix)
{				
	_model.glPushMatrix();
	effectTransformations();
	glBindVertexArray(_vaoHandle);	
	glm::mat4 mvpMatrix = proj_matrix * view_matrix * _model.getMatrix();
	glUniformMatrix4fv(shader->uniform("mvp"), 1, GL_FALSE, glm::value_ptr(mvpMatrix));
	glm::mat4 modelview = view_matrix * _model.getMatrix();	
	_model.glPopMatrix();
	glUniform4fv(shader->uniform("LightLocation"), 1, glm::value_ptr(view_matrix * glm::vec4(50, 50, 50, 1)));
	glUniformMatrix4fv(shader->uniform("ModelViewMatrix"), 1, GL_FALSE, glm::value_ptr(modelview));
	glm::mat4 inverseModelView = glm::inverse(modelview);
	glm::mat3 normalMatrix = glm::mat3(glm::transpose(inverseModelView));
	glUniformMatrix3fv(shader->uniform("NormalMatrix"), 1, GL_FALSE, glm::value_ptr(normalMatrix));

	if (ibo_used)
	{
		int size;
		glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
		glDrawElements(GL_TRIANGLES, size / sizeof(GLushort), GL_UNSIGNED_SHORT, 0);
	}
	else
		glDrawArrays(GL_TRIANGLES, 0, 36);	



}

DrawableType ColorCube::getType()
{
	return DrawableType::COLOR_CUBE;
}

ColorCube::~ColorCube()
{
}