VideoRenderer.cpp

#include <iostream>

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

#include "Texture.h"
#include "VideoRenderer.h"

using namespace std;

bool sen::VideoRenderer::setup(const std::string &vertex_shader_file, const std::string &fragment_shader_file)
{
	programID = LoadShaders(vertex_shader_file, fragment_shader_file);
	MatrixID = glGetUniformLocation(programID, "MVP");
	return true;
}

bool sen::VideoRenderer::initTexture(const k4a::image &frame)
{
	texture_id = createTexture();
	TextureID = glGetUniformLocation(programID, "myTextureSampler");

	int texture_width = frame.get_width_pixels();
	int texture_height = frame.get_height_pixels();

	const GLfloat bgTextureVertices[] = { 0, 0, (float)texture_width, 0, 0, (float)texture_height, (float)texture_width, (float)texture_height };
	const GLfloat bgTextureCoords[] = { 1, 0, 1, 1, 0, 0, 0, 1 };

	glGenBuffers(1, &vertexBuffer);
	glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
	glBufferData(GL_ARRAY_BUFFER, sizeof(bgTextureVertices), bgTextureVertices, GL_STATIC_DRAW);

	glGenBuffers(1, &uvBuffer);
	glBindBuffer(GL_ARRAY_BUFFER, uvBuffer);
	glBufferData(GL_ARRAY_BUFFER, sizeof(bgTextureCoords), bgTextureCoords, GL_STATIC_DRAW);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width, texture_height, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, frame.get_buffer());

	return true;
}

void sen::VideoRenderer::render(const k4a::image &frame)
{
	int texture_width = frame.get_width_pixels();
	int texture_height = frame.get_height_pixels();

	const GLfloat proj[] = {
		0, -2.f / texture_width, 0, 0,
		-2.f / texture_height, 0, 0, 0,
		0, 0, 1, 0,
		1, 1, 0, 1 };
	glm::mat4 Projection = glm::make_mat4(proj);
	glm::mat4 View = glm::mat4(1.0f);
	glm::mat4 Model = glm::mat4(1.0f);
	MVP = Projection * View * Model;

	glClearColor(1, 1, 1, 1);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glUseProgram(programID);
	glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, texture_id);
	glUniform1i(TextureID, 0);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width, texture_height, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, frame.get_buffer());

	glEnableVertexAttribArray(0);
	glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, (void*)0);

	glEnableVertexAttribArray(1);
	glBindBuffer(GL_ARRAY_BUFFER, uvBuffer);
	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, (void*)0);

	glColor4f(1, 1, 1, 1);
	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

	glDisableVertexAttribArray(0);
	glDisableVertexAttribArray(1);
}

void sen::VideoRenderer::deleteBuffer()
{
	glDeleteBuffers(1, &vertexBuffer);
	glDeleteBuffers(1, &uvBuffer);
	glDeleteProgram(programID);
	glDeleteTextures(1, &texture_id);
}