Nigel/LearnOpenGL
1
0
Fork 0
Code Issues Pull Requests repo.project_board Releases Wiki Activity

Added framebuffer objects to allow postprocessing on a texture of the screen

Browse Source
This commit is contained in:
Nigel Barink
2022-10-16 18:26:50 +02:00
parent 3d4d81f260
commit d8e87b4787
9 changed files with 322 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files

218
src/main.cpp
View File

@ -11,6 +11,10 @@
#include "shader.h"
#include "camera.h"
#include "model.h"
#include "FrameBuffer.hpp"
#include "RenderBuffer.hpp"
// https://learnopengl.com/Advanced-OpenGL/Framebuffers
float deltaTime = 0.0f; // Time between current frame and last frame
float lastFrame = 0.0f; // Time of last frame
@ -19,8 +23,23 @@ Camera camera(glm::vec3(0.0f, 0.0f, 8.0f));
float lastX = 400, lastY = 300;
bool firstMouse = true;
glm::mat4 model = glm::mat4(1.0f);
glm::mat4 view;
glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)800 / (float)600, 0.1f, 100.0f);
glm::vec3 lightpos(-0.2f, -1.0f, -0.3f);
std::vector<float> ScreenVertices = {
// vertex , uv
-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,
} ;
void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
glViewport(0,0, width, height);
}
@ -40,7 +59,6 @@ void processInput( GLFWwindow* window){
camera.ProcessKeyboard(RIGHT,deltaTime);
}
void mouse_callback(GLFWwindow* window, double xpos, double ypos){
if (firstMouse) // initially set to true
{
@ -62,9 +80,9 @@ void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
camera.ProcessMouseScroll(yoffset);
}
int main() {
printf("Hello OpenGL!\n");
glfwInit();
GLFWwindow* CreateWindowWithOpenGLContext()
{
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
@ -74,13 +92,13 @@ int main() {
if( window == NULL){
printf("Failed to create GLFW window!\n");
glfwTerminate();
return -1;
return nullptr;
}
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){
printf("Failed to initialize GLAD!\n");
return -1;
return nullptr;
}
glViewport(0,0, 800, 600);
@ -89,79 +107,181 @@ int main() {
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
glEnable(GL_DEPTH_TEST);
stbi_set_flip_vertically_on_load(true);
return window;
}
Shader shader ("shader.vs", "shader.fs");
Shader outlineShader("shader.vs","outlineshader.fs");
Model backpack("Models/backpack.obj");
glEnable(GL_DEPTH_TEST);
glEnable(GL_STENCIL_TEST);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
///glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
while(!glfwWindowShouldClose(window))
void drawScene_pass(Shader& shader, Model& Object)
{
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// std::cout << "Delta Time: " << deltaTime << std::endl;
processInput(window);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
glm::mat4 model = glm::mat4(1.0f);
glm::mat4 view = camera.GetViewMatrix();
glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)800 / (float)600, 0.1f, 100.0f);
model = glm::mat4(1.0);
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glStencilFunc(GL_ALWAYS, 1, 0xff);
glStencilMask(0xFF);
shader.use();
shader.setMat4("model", model);
shader.setMat4("view", view);
shader.setMat4("projection", projection);
Object.Draw(shader);
}
backpack.Draw(shader);
void outline_pass( Shader& shader, Model& Object)
{
glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
glStencilMask(0x00);
glDisable(GL_DEPTH_TEST);
outlineShader.use();
outlineShader.setMat4("model", model);
outlineShader.setMat4("view", view);
outlineShader.setMat4("projection", projection);
outlineShader.setVec3("outlineColor", glm::vec3(0.28, 0.10, 0.26));
shader.use();
shader.setMat4("model", model);
shader.setMat4("view", view);
shader.setMat4("projection", projection);
shader.setVec3("outlineColor", glm::vec3(0.28, 0.10, 0.26));
model = glm::scale(model, glm::vec3(1.05f,1.05f, 1.05f));
// model = glm::translate(model, glm::vec3(1.0f, 0.0f, 0.0f));
outlineShader.setMat4("model", model);
shader.setMat4("model", model);
Object.Draw(shader);
}
void DrawToScreen( GLuint& VAO, GLuint& ScreenTexture, Shader& shader)
{
// draw to screen
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDisable(GL_DEPTH_TEST);
glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
backpack.Draw(outlineShader);
shader.use();
shader.setInt("screenTexture",0);
glBindVertexArray(VAO);
glBindTexture(GL_TEXTURE_2D, ScreenTexture);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
int main() {
printf("Hello OpenGL!\n");
// Setup OpenGL Context
GLFWwindow* window = CreateWindowWithOpenGLContext();
if(window == nullptr)
return -1;
glEnable(GL_DEPTH_TEST);
stbi_set_flip_vertically_on_load(true);
// Load scene resources
Shader shader ("shader.vs", "shader.fs");
Shader outlineShader("shader.vs","outlineshader.fs");
Shader framebufferShader("Framebuffers.vs", "Framebuffers.fs" );
Model backpack("Models/backpack.obj");
// Framebuffer outline effect
FrameBuffer outlineFrameBuffer = FrameBuffer();
outlineFrameBuffer.Bind();
// Create a texture attachment (colour attachment)
Texture* depthTexture = CreateTexture(800,600);
// attach texture to the frame buffer as a colour attachment
outlineFrameBuffer.Attach(*depthTexture);
// Add depth buffer attachment
RenderBuffer outlineRenderBuffer = RenderBuffer();
outlineRenderBuffer.Bind();
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 800, 600);
outlineRenderBuffer.Unbind();
// attach depth buffer to our framebuffer
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, outlineRenderBuffer.id);
outlineFrameBuffer.Unbind();
// Post processing
FrameBuffer framebuffer = FrameBuffer();
framebuffer.Bind();
Texture* ColourBuffer = CreateTexture(800,600);
framebuffer.Attach(*ColourBuffer);
RenderBuffer renderbufferObject = RenderBuffer();
renderbufferObject.Bind();
renderbufferObject.UseDepthAndStencil();
renderbufferObject.Unbind();
framebuffer.Attach(renderbufferObject);
if(framebuffer.IsComplete() == false ){
std::cout << "ERROR::FRAMEBUFFER::Framebuffer is not complete! " << std::endl;
}
framebuffer.Unbind();
// Create ScreenVAO
GLuint ScreenVAO, VBO;
glGenVertexArrays(1, &ScreenVAO);
glBindVertexArray(ScreenVAO);
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, ScreenVertices.size() * sizeof(float), &ScreenVertices[0], 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)));
glBindVertexArray(0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_STENCIL_TEST);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
while(!glfwWindowShouldClose(window))
{
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
processInput(window);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
// Recalculate the Camera's view matrix
view = camera.GetViewMatrix();
// Reset the model matrix to an identity matrix
model = glm::mat4(1.0f);
framebuffer.Bind();
drawScene_pass(shader, backpack);
outline_pass(outlineShader, backpack);
// Reset stencil
glStencilMask(0xFF);
glStencilFunc(GL_ALWAYS, 1, 0xFF);
glEnable(GL_DEPTH_TEST);
DrawToScreen(ScreenVAO, ColourBuffer->id, framebufferShader);
glfwSwapBuffers(window);
glfwPollEvents();
}
delete ColourBuffer;
delete depthTexture;
glfwTerminate();
return 0;