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Code re-work: anti-aliasing.

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This commit is contained in:
Joey de Vries
2017-04-20 21:30:22 +02:00
parent cd5f93211b
commit 9994831d5d
8 changed files with 270 additions and 182 deletions
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5
CMakeLists.txt
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@@ -122,9 +122,10 @@ set(4.advanced_opengl
8.advanced_glsl_ubo
9.1.geometry_shader_houses
9.2.geometry_shader_exploding
9.3.geometry_shader_normal_visualization
9.3.geometry_shader_normals
10.1.instancing_quads
10.2.instancing_asteroids
10.2.asteroids
10.3.asteroids_instanced
11.anti_aliasing_offscreen
)

7
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.1.anti_aliasing.fs Normal file
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@@ -0,0 +1,7 @@
#version 330 core
out vec4 FragColor;
void main()
{
FragColor = vec4(0.0, 1.0, 0.0, 1.0);
}

11
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.1.anti_aliasing.vs Normal file
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@@ -0,0 +1,11 @@
#version 330 core
layout (location = 0) in vec3 aPos;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4(aPos, 1.0f);
}

13
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.2.aa_post.fs Normal file
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@@ -0,0 +1,13 @@
#version 330 core
out vec4 FragColor;
in vec2 TexCoords;
uniform sampler2D screenTexture;
void main()
{
vec3 col = texture(screenTexture, TexCoords).rgb;
float grayscale = 0.2126 * col.r + 0.7152 * col.g + 0.0722 * col.b;
FragColor = vec4(vec3(grayscale), 1.0);
}

11
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.2.aa_post.vs Normal file
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@@ -0,0 +1,11 @@
#version 330 core
layout (location = 0) in vec2 aPos;
layout (location = 1) in vec2 aTexCoords;
out vec2 TexCoords;
void main()
{
TexCoords = aTexCoords;
gl_Position = vec4(aPos.x, aPos.y, 0.0, 1.0);
}

7
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.anti_aliasing.fs
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@@ -1,7 +0,0 @@
#version 330 core
out vec4 color;
void main()
{
color = vec4(0.0, 1.0, 0.0, 1.0);
}

11
src/4.advanced_opengl/11.anti_aliasing_offscreen/11.anti_aliasing.vs
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@@ -1,11 +0,0 @@
#version 330 core
layout (location = 0) in vec3 position;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4(position, 1.0f);
}

387
src/4.advanced_opengl/11.anti_aliasing_offscreen/anti_aliasing_offscreen.cpp
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@@ -1,255 +1,318 @@
// GLEW
#define GLEW_STATIC
#include <GL/glew.h>
// GLFW
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <stb_image.h>
// GL includes
#include <learnopengl/shader.h>
#include <learnopengl/camera.h>
// GLM Mathemtics
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
// Properties
GLuint screenWidth = 800, screenHeight = 600;
#include <learnopengl/filesystem.h>
#include <learnopengl/shader.h>
#include <learnopengl/camera.h>
#include <learnopengl/model.h>
// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
#include <iostream>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void Do_Movement();
GLuint generateMultiSampleTexture(GLuint samples);
void processInput(GLFWwindow *window);
// Camera
// settings
const unsigned int SCR_WIDTH = 1280;
const unsigned int SCR_HEIGHT = 720;
// camera
Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
bool keys[1024];
GLfloat lastX = 400, lastY = 300;
float lastX = (float)SCR_WIDTH / 2.0;
float lastY = (float)SCR_HEIGHT / 2.0;
bool firstMouse = true;
GLfloat deltaTime = 0.0f;
GLfloat lastFrame = 0.0f;
// timing
float deltaTime = 0.0f;
float lastFrame = 0.0f;
// The MAIN function, from here we start our application and run our Game loop
int main()
{
// Init GLFW
// glfw: initialize and configure
// ------------------------------
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
GLFWwindow* window = glfwCreateWindow(screenWidth, screenHeight, "LearnOpenGL", nullptr, nullptr); // Windowed
// glfw window creation
// --------------------
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
glfwMakeContextCurrent(window);
// Set the required callback functions
glfwSetKeyCallback(window, key_callback);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
// Options
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
// tell GLFW to capture our mouse
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
// Initialize GLEW to setup the OpenGL Function pointers
glewExperimental = GL_TRUE;
glewInit();
// glad: load all OpenGL function pointers
// ---------------------------------------
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
// Define the viewport dimensions
glViewport(0, 0, screenWidth, screenHeight);
// Setup OpenGL options
glEnable(GL_MULTISAMPLE); // Enabled by default on some drivers, but not all so always enable to make sure
// configure global opengl state
// -----------------------------
glEnable(GL_DEPTH_TEST);
// Setup and compile our shaders
Shader shader("anti_aliasing.vs", "anti_aliasing.frag");
// build and compile shaders
// -------------------------
Shader shader("11.1.anti_aliasing.vs", "11.1.anti_aliasing.fs");
Shader screenShader("11.2.aa_post.vs", "11.2.aa_post.fs");
#pragma region "object_initialization"
// Set the object data (buffers, vertex attributes)
GLfloat cubeVertices[] = {
// Positions
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
// set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
float cubeVertices[] = {
// positions
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
0.5f, 0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f
};
// Setup cube VAO
GLuint cubeVAO, cubeVBO;
float quadVertices[] = { // vertex attributes for a quad that fills the entire screen in Normalized Device Coordinates.
// positions // texCoords
-1.0f, 1.0f, 0.0f, 1.0f,
-1.0f, -1.0f, 0.0f, 0.0f,
1.0f, -1.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 0.0f, 1.0f,
1.0f, -1.0f, 1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f
};
// setup cube VAO
unsigned int cubeVAO, cubeVBO;
glGenVertexArrays(1, &cubeVAO);
glGenBuffers(1, &cubeVBO);
glBindVertexArray(cubeVAO);
glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), &cubeVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
glBindVertexArray(0);
#pragma endregion
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
// setup screen VAO
unsigned int quadVAO, quadVBO;
glGenVertexArrays(1, &quadVAO);
glGenBuffers(1, &quadVBO);
glBindVertexArray(quadVAO);
glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
// Framebuffers
GLuint framebuffer;
// configure MSAA framebuffer
// --------------------------
unsigned int framebuffer;
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
// Create a multisampled color attachment texture
GLuint textureColorBufferMultiSampled = generateMultiSampleTexture(4);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
// create a multisampled color attachment texture
unsigned int textureColorBufferMultiSampled;
glGenTextures(1, &textureColorBufferMultiSampled);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, textureColorBufferMultiSampled);
glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB, SCR_WIDTH, SCR_HEIGHT, GL_TRUE);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, textureColorBufferMultiSampled, 0);
// Create a renderbuffer object for depth and stencil attachments
GLuint rbo;
// create a (also multisampled) renderbuffer object for depth and stencil attachments
unsigned int rbo;
glGenRenderbuffers(1, &rbo);
glBindRenderbuffer(GL_RENDERBUFFER, rbo);
glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, screenWidth, screenHeight);
glBindRenderbuffer(GL_RENDERBUFFER, rbo);
glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, SCR_WIDTH, SCR_HEIGHT);
glBindRenderbuffer(GL_RENDERBUFFER, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);
if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
std::cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!" << std::endl;
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!" << endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// Game loop
while(!glfwWindowShouldClose(window))
// configure second post-processing framebuffer
unsigned int intermediateFBO;
glGenFramebuffers(1, &intermediateFBO);
glBindFramebuffer(GL_FRAMEBUFFER, intermediateFBO);
// create a color attachment texture
unsigned int screenTexture;
glGenTextures(1, &screenTexture);
glBindTexture(GL_TEXTURE_2D, screenTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, screenTexture, 0); // we only need a color buffer
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
cout << "ERROR::FRAMEBUFFER:: Intermediate framebuffer is not complete!" << endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// shader configuration
// --------------------
shader.use();
screenShader.setInt("screenTexture", 0);
// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// Set frame time
GLfloat currentFrame = glfwGetTime();
// per-frame time logic
// --------------------
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// Check and call events
glfwPollEvents();
Do_Movement();
// 1. Draw scene as normal in multisampled buffers
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
// input
// -----
processInput(window);
// render
// ------
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 1. draw scene as normal in multisampled buffers
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
// Set transformation matrices
shader.Use();
glm::mat4 projection = glm::perspective(camera.Zoom, (GLfloat)screenWidth/(GLfloat)screenHeight, 0.1f, 1000.0f);
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "view"), 1, GL_FALSE, glm::value_ptr(camera.GetViewMatrix()));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(glm::mat4()));
shader.use();
glm::mat4 projection = glm::perspective(camera.Zoom, (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 1000.0f);
shader.setMat4("projection", projection);
shader.setMat4("view", camera.GetViewMatrix());
shader.setMat4("model", glm::mat4());
glBindVertexArray(cubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
// 2. Now blit multisampled buffer(s) to default framebuffers
// 2. now blit multisampled buffer(s) to normal colorbuffer of intermediate FBO. Image is stored in screenTexture
glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glBlitFramebuffer(0, 0, screenWidth, screenHeight, 0, 0, screenWidth, screenHeight, GL_COLOR_BUFFER_BIT, GL_NEAREST);
// Swap the buffers
glfwSwapBuffers(window);
}
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediateFBO);
glBlitFramebuffer(0, 0, SCR_WIDTH, SCR_HEIGHT, 0, 0, SCR_WIDTH, SCR_HEIGHT, GL_COLOR_BUFFER_BIT, GL_NEAREST);
// 3. now render quad with scene's visuals as its texture image
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glDisable(GL_DEPTH_TEST);
// Draw Screen quad
screenShader.use();
glBindVertexArray(quadVAO);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, screenTexture); // use the now resolved color attachment as the quad's texture
glDrawArrays(GL_TRIANGLES, 0, 6);
// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
// -------------------------------------------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}
GLuint generateMultiSampleTexture(GLuint samples)
// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow *window)
{
GLuint texture;
glGenTextures(1, &texture);
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, texture);
glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGB, screenWidth, screenHeight, GL_TRUE);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
return texture;
}
#pragma region "User input"
// Moves/alters the camera positions based on user input
void Do_Movement()
{
// Camera controls
if(keys[GLFW_KEY_W])
float cameraSpeed = 2.5 * deltaTime;
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
camera.ProcessKeyboard(FORWARD, deltaTime);
if(keys[GLFW_KEY_S])
if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
camera.ProcessKeyboard(BACKWARD, deltaTime);
if(keys[GLFW_KEY_A])
if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
camera.ProcessKeyboard(LEFT, deltaTime);
if(keys[GLFW_KEY_D])
if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
camera.ProcessKeyboard(RIGHT, deltaTime);
}
// Is called whenever a key is pressed/released via GLFW
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
if(key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
glfwSetWindowShouldClose(window, GL_TRUE);
if(action == GLFW_PRESS)
keys[key] = true;
else if(action == GLFW_RELEASE)
keys[key] = false;
// make sure the viewport matches the new window dimensions; note that width and
// height will be significantly larger than specified on retina displays.
glViewport(0, 0, width, height);
}
// glfw: whenever the mouse moves, this callback is called
// -------------------------------------------------------
void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
if(firstMouse)
if (firstMouse)
{
lastX = xpos;
lastY = ypos;
firstMouse = false;
}
GLfloat xoffset = xpos - lastX;
GLfloat yoffset = lastY - ypos;
float xoffset = xpos - lastX;
float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
lastX = xpos;
lastY = ypos;
camera.ProcessMouseMovement(xoffset, yoffset);
}
}
// glfw: whenever the mouse scroll wheel scrolls, this callback is called
// ----------------------------------------------------------------------
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
camera.ProcessMouseScroll(yoffset);
}
#pragma endregion
}