#include "texture_display_vertex_buffer.h"

TextureDisplayVertexBuffer::TextureDisplayVertexBuffer():
	_data{
		-1.f,  1.f, 0.f, 1.f,
		-1.f, -1.f, 0.f, 0.f,
		 1.f, -1.f, 1.f, 0.f,

		-1.f,  1.f, 0.f, 1.f,
		 1.f, -1.f, 1.f, 0.f,
		 1.f,  1.f, 1.f, 1.f
	} {
	glGenVertexArrays(1, &_array);
	glGenBuffers(1, &_buffer);

	glBindVertexArray(_array);
	glBindBuffer(GL_ARRAY_BUFFER, _buffer);
	glBufferData(
		GL_ARRAY_BUFFER,
		_data.size() * sizeof(GLfloat),
		_data.data(),
		GL_DYNAMIC_DRAW
	);

	glEnableVertexAttribArray(0);
	glVertexAttribPointer(
		0, 2, GL_FLOAT, GL_FALSE, 4*sizeof(GLfloat), (void*)0);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(
		1, 2, GL_FLOAT, GL_FALSE, 4*sizeof(GLfloat), (void*)(2*sizeof(GLfloat)));
}

TextureDisplayVertexBuffer::~TextureDisplayVertexBuffer() {
	glDeleteBuffers(1, &_buffer);
	glDeleteVertexArrays(1, &_array);
}

GLuint TextureDisplayVertexBuffer::getBuffer() const {
	return _buffer;
}

void TextureDisplayVertexBuffer::draw(const std::vector<GLuint>& textures) const {
	glBindVertexArray(_array);
	glBindTextures(textures[0], textures.size(), textures.data());
	glDrawArrays(GL_TRIANGLES, 0, 6);
}