#include "Sprite.h"

#include "Vertex.h"

#include "ResourceManager.h"

#include <cstddef>

namespace Bengine {

Sprite::Sprite()

{

_vboID = 0;

}

Sprite::~Sprite()

{

//Always remember to delete your buffers when

//you are done!

if (_vboID != 0) {

glDeleteBuffers(1, &_vboID);

}

}

//Initializes the sprite VBO. x, y, width, and height are

//in the normalized device coordinate space. so, [-1, 1]

void Sprite::init(float x, float y, float width, float height, std::string texturePath) {

//Set up our private vars

_x = x;

_y = y;

_width = width;

_height = height;

_texture = ResourceManager::getTexture(texturePath);

//Generate the buffer if it hasn't already been generated

if (_vboID == 0) {

glGenBuffers(1, &_vboID);

}

//This array will hold our vertex data.

//We need 6 vertices, and each vertex has 2

//floats for X and Y

Vertex vertexData[6];

//First Triangle

vertexData[0].setPosition(x + width, y + height);

vertexData[0].setUV(1.0f, 1.0f);

vertexData[1].setPosition(x, y + height);

vertexData[1].setUV(0.0f, 1.0f);

vertexData[2].setPosition(x, y);

vertexData[2].setUV(0.0f, 0.0f);

//Second Triangle

vertexData[3].setPosition(x, y);

vertexData[3].setUV(0.0f, 0.0f);

vertexData[4].setPosition(x + width, y);

vertexData[4].setUV(1.0f, 0.0f);

vertexData[5].setPosition(x + width, y + height);

vertexData[5].setUV(1.0f, 1.0f);

//Set all vertex colors to magenta

for (int i = 0; i < 6; i++) {

vertexData[4].setColor(255, 0, 255, 255);

}

vertexData[4].setColor(0, 0, 255, 255);

vertexData[4].setColor(0, 255, 0, 255);

//Tell opengl to bind our vertex buffer object

glBindBuffer(GL_ARRAY_BUFFER, _vboID);

//Upload the data to the GPU

glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);

//Unbind the buffer (optional)

glBindBuffer(GL_ARRAY_BUFFER, 0);

}

//Draws the sprite to the screen

void Sprite::draw() {

glBindTexture(GL_TEXTURE_2D, _texture.id);

//bind the buffer object

glBindBuffer(GL_ARRAY_BUFFER, _vboID);

//Tell opengl what attribute arrays we need

glEnableVertexAttribArray(0);

glEnableVertexAttribArray(1);

glEnableVertexAttribArray(2);

//This is the position attribute pointer

glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, position));

//This is the color attribute pointer

glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex), (void*)offsetof(Vertex, color));

//This is the UV attribute pointer

glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, uv));

//Draw the 6 vertices to the screen

glDrawArrays(GL_TRIANGLES, 0, 6);

//Disable the vertex attrib arrays. This is not optional.

glDisableVertexAttribArray(0);

glDisableVertexAttribArray(1);

glDisableVertexAttribArray(2);

//Unbind the VBO

glBindBuffer(GL_ARRAY_BUFFER, 0);

}

}