Jump to content
  • Advertisement
Sign in to follow this  

OpenGL engine repair

This topic is 3644 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I was wondering if I could get some help fixing some bugs and glitches within my engine. I am new to the whole opengl language so if I am doing anything wrong please let me know. My main problem is setting up the projection direction system. Some help could be really um helpful...
#include <gl/gl.h>
#include <gl/glu.h>
#include <gl/glut.h>
using namespace std;

float cord_x=50.0;
float cord_y=0.0;
float cord_z=50.0;

float yaw=0.0;  //direction
float pitch=0.0;  //zdirection
float roll=0.0;  //spin

float pi=3.141592654;

void keypress(unsigned char key, int x, int y)
{
     switch(key)
          {
               case 27:
                    
               case 'a':
                    yaw-=2.0;
                    break; 
                    
               case 'd':
                    yaw+=2.0;
                    break; 
                    
               case 'w':
                    pitch+=2.0;
                    break; 
                    
               case 's':
                    pitch-=2.0;
                    break; 
          }
          glutPostRedisplay();
}

void init()
{
     glClearColor(0,0,0,0);
     glEnable(GL_DEPTH_TEST);
}

void projection(int width, int height)
{    
     //glViewport(0,0,width,height);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluPerspective(45.0f,width/height,1.0f,10000.0f);
}

void display()
{  
     float room_width=255;
     float room_height=255;
     
     glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
     
     gluLookAt(cord_x,cord_y+5,cord_z,yaw,pitch,0.0,0.0,1.0,0.0);
        
     glBegin(GL_POLYGON);
     glColor3d(.25,.25,.25);
     glVertex3f(0,0,0); glVertex3f(room_width,0,0);
     glVertex3f(room_width,0,room_height); glVertex3f(0,0,room_height);
     glEnd();
          
     glBegin(GL_POLYGON);
     glColor3d(0,0,1);
     glVertex3f(-2,0,0); glVertex3f(2,0,0);
     glVertex3f(2,3,0); glVertex3f(-2,3,0);
     glEnd();
     
     glBegin(GL_POLYGON);
     glColor3d(0,1,0);
     glVertex3f(room_width-2,0,0); glVertex3f(room_width+2,0,0);
     glVertex3f(room_width+2,3,0); glVertex3f(room_width-2,3,0);
     glEnd();
     
     glBegin(GL_POLYGON);
     glColor3d(1,0,0);
     glVertex3f(room_width-2,0,room_height); glVertex3f(room_width+2,0,room_height);
     glVertex3f(room_width+2,3,room_height); glVertex3f(room_width-2,3,room_height);
     glEnd();
     
     glBegin(GL_POLYGON);
     glColor3d(.5,.5,0);
     glVertex3f(-2,0,room_height); glVertex3f(2,0,room_height);
     glVertex3f(2,3,room_height); glVertex3f(-2,3,room_height);
     glEnd();
     
     glutSwapBuffers();
     glutPostRedisplay();
}

void step()
{
     //step loop
}

//last fuction
int main(int argc,char**argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(480,480);
    glutInitWindowPosition(25,25);
    glutCreateWindow("alpha engine");
    init();
    
    glutDisplayFunc(display);
    glutIdleFunc(step);
    glutReshapeFunc(projection);
    glutKeyboardFunc(keypress);
    
    glutMainLoop();
    return 0;
}

Share this post


Link to post
Share on other sites
Advertisement
What do you mean by that, because I might know? I have been doing some research on gluLookAt and found very little info for what I am looking at doing. From what I read the first three digits are the cameras location, the next 6 digits are uncertain to me.

I am sure this looks and sounds like a large task, and I am sorry about that. I have reached a roadblock and the only way to pass it is with a little professional revision.

Share this post


Link to post
Share on other sites
The first three parameters are the Eye vector (where your looking from), the next three are the LookAt vector (where you're looking at), and the final three parameters are the up vector (which way points up). The values (yaw & pitch) you are passing in are wrong.

As a side note, before writing an "engine", I would suggest reading and fully understanding how the OpenGL API works. It will definitely shed some light as to how things work. Have you tried searching through OpenGL.org for information?

RANT: Why make an engine, and not a game instead? Or at least a few demos to fully understand how it all works? In it's current state, your code is like a Ford Fiesta or a Pinto. Far from being a fully featured commercial (or Open Source) engine. All too often, people use this magical term of "engine" to describe everything from a text-based adventure game to their "industry breaking MMO" idea.

When will we see people just write a game and not see the in-experienced trying to be like Carmack or Sweeney or Abrash or any of the well-experienced game/engine programmers. I'm NOT directing this at you specifically, but a more broad comment about so many posts here. It seems like almost every post heading has either MMO or Engine in the title. More people should focus on making games, gaining experience and having fun than trying to design the next Unreal Engine and ultimately fail because they do not have enough experience to know all of the pitfalls and design complexities associated with such a task.

Share this post


Link to post
Share on other sites
Man you got me all wrong, your definition and mine of engine must be different. This is meant for a game but I can't really call it that while its in this really early state of development. Listen I have 4 years of game making experience, I am not that retarded to think that I am making the next Doom or Half-Life game. I have just started learning opengl and its more complex than what I was previously using, its alot harder to learn and master. I currently know many game makering concepts(I am alot less of a noob than you give credit for) but am having some issues learning all the commands and learning about how opengl runs. I know what I currently have isn't worth crap, and that is why I am trying to work out all the kinks now.

Share this post


Link to post
Share on other sites
Quote:
Original post by snowfell
Man you got me all wrong, your definition and mine of engine must be different. This is meant for a game but I can't really call it that while its in this really early state of development. Listen I have 4 years of game making experience, I am not that retarded to think that I am making the next Doom or Half-Life game. I have just started learning opengl and its more complex than what I was previously using, its alot harder to learn and master. I currently know many game makering concepts(I am alot less of a noob than you give credit for) but am having some issues learning all the commands and learning about how opengl runs. I know what I currently have isn't worth crap, and that is why I am trying to work out all the kinks now.


Sorry but I get irked pretty at times about the word "engine" being used so much...In either case, I have a few helpful suggestions for your code:

- IF you have to redefine PI, change your definition of pi to the maximum number of decimal places for the given platform (i.e. 4) and don't forget to add an 'f' at the end to re-enforce it's a float. Otherwise some compilers will make it a double and cast it to a float at compile time. This could be done everywhere. i.e. float pi=3.1415f;
- When using glBegin/glEnd pairs, put as many primitives in them as possible. This will speed things up when rendering in Immediate mode. Since your using GL_POLYGON for a wall, consider using GL_QUADS so each wall will be split after 4 vertices are added. If you don't change the type being created, all points you add will be connected into one fugly looking object. Keep in mind that usually Triangles (or Triangle Strips) give the best performance although this may not always be the case (depending on hardware)
- Unless your debugging something, it is not good to use Immediate mode rendering (glBegin/glEnd calls), instead consider using Vertex Arrays or Vertex Buffer Objects. You will see a considerable speed increase.
- Reduce or eliminate the use of Doubles in your code (speed), unless you need that extra precision which is highly unlikely.
- Change glColor3d to either glColor3f (float) or ideally glColor3ub (unsigned bytes) because you won't see that extra visual precision on 32-bit colour and it's faster.

[Edited by - shwasasin on May 28, 2008 5:05:20 PM]

Share this post


Link to post
Share on other sites
No problem, I know what you mean about poser game programmers.

Those tips all seem to make sense to me, but my main issues are revolving around the camera direction code. I am trying to set up motion for a simple fps camera but I am having some issues. What I currently have set is obviously wrong, and I was wondering what type of commands I would look into to get it fixed. All that code does right now is turn about 25 degrees in both ways then stops. Any suggestions?

Share this post


Link to post
Share on other sites
Quote:
Original post by snowfell
No problem, I know what you mean about poser game programmers.

Those tips all seem to make sense to me, but my main issues are revolving around the camera direction code. I am trying to set up motion for a simple fps camera but I am having some issues. What I currently have set is obviously wrong, and I was wondering what type of commands I would look into to get it fixed. All that code does right now is turn about 25 degrees in both ways then stops. Any suggestions?


The problem, as far as I can see in your code is that you're not actually rotating anything. To solve this, you'll need to dust off those old trigonometry books from high school. This is something I whipped up quickly and probably has compile errors but it will give you a quick idea as to what's going on. I should mention that the player_x/z are the Eye, and the lookat_x/z is, well, the lookat for use the with the gluLookAt function. :)


float player_x = 0.0f; // This is the players position in the world
float player_y = 0.0f;
float player_z = 0.0f;
float player_yaw = 0.0f; // What direction he's facing (I'm not worried about P/R)
float player_speed = 64.0f;
float lookat_x = 0.0f; // Current view pos
float lookat_z = 0.0f;
float lookat_distance = 1000.0f;

void player_forward(void)
{
// To turn, uncomment below, 1.0f = 1d
// player_yaw += 1.0f;
const float rad = M_PI / 180.0f * player_yaw;
const float s = sinf( rad );
const float c = cosf( rad );

// Move player
player_x += (s * player_speed);
player_z -= (c * player_speed);

// Update lookAt
lookat_x = player_x + (s * lookat_distance); // Update view once
lookat_z = player_z - (c * lookat_distance);
}




[Edited by - shwasasin on May 28, 2008 6:48:09 PM]

Share this post


Link to post
Share on other sites
ah so that is why I couldn't figure it out. Never took trig yet, not till college. So this is a general way of getting the camera to move?

Share this post


Link to post
Share on other sites
Quote:
Original post by snowfell
ah so that is why I couldn't figure it out. Never took trig yet, not till college. So this is a general way of getting the camera to move?


This is one of many ways to do it. I used the player_x/z position as the camera eye because generally in FPS's the player and the camera are linked (you see through the players eyes). Although in a real-world situation you would want to change the eye_y to be different than the player_y (depending on how you code things), because you could be potentially looking through their feet. With the code provided and a bit of tweaking you could easily make the camera/player go forward/backward, strafe left/right, and turn left/right.

Definitely read up on the trigonometry stuff (sin, cos, tan, etc...) to get a better idea on how it all works as these are important concepts for gaming. And let me know if you have questions, I won't bark (this time)!

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
  • Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • By mmmax3d
      Hi everyone,
      I would need some assistance from anyone who has a similar experience
      or a nice idea!
      I have created a skybox (as cube) and now I need to add a floor/ground.
      The skybox is created from cubemap and initially it was infinite.
      Now it is finite with a specific size. The floor is a quad in the middle
      of the skybox, like a horizon.
      I have two problems:
      When moving the skybox upwards or downwards, I need to
      sample from points even above the horizon while sampling
      from the botton at the same time.  I am trying to create a seamless blending of the texture
      at the points of the horizon, when the quad is connected
      to the skybox. However, I get skew effects. Does anybody has done sth similar?
      Is there any good practice?
      Thanks everyone!
    • By mmmax3d
      Hi everyone,
      I would need some assistance from anyone who has a similar experience
      or a nice idea!
      I have created a skybox (as cube) and now I need to add a floor/ground.
      The skybox is created from cubemap and initially it was infinite.
      Now it is finite with a specific size. The floor is a quad in the middle
      of the skybox, like a horizon.
      I have two problems:
      When moving the skybox upwards or downwards, I need to
      sample from points even above the horizon while sampling
      from the botton at the same time.  I am trying to create a seamless blending of the texture
      at the points of the horizon, when the quad is connected
      to the skybox. However, I get skew effects. Does anybody has done sth similar?
      Is there any good practice?
      Thanks everyone!
    • By iArtist93
      I'm trying to implement PBR into my simple OpenGL renderer and trying to use multiple lighting passes, I'm using one pass per light for rendering as follow:
      1- First pass = depth
      2- Second pass = ambient
      3- [3 .. n] for all the lights in the scene.
      I'm using the blending function glBlendFunc(GL_ONE, GL_ONE) for passes [3..n], and i'm doing a Gamma Correction at the end of each fragment shader.
      But i still have a problem with the output image it just looks noisy specially when i'm using texture maps.
      Is there anything wrong with those steps or is there any improvement to this process?
    • By babaliaris
      Hello Everyone!
      I'm learning openGL, and currently i'm making a simple 2D game engine to test what I've learn so far.  In order to not say to much, i made a video in which i'm showing you the behavior of the rendering.
      Video: 
       
      What i was expecting to happen, was the player moving around. When i render only the player, he moves as i would expect. When i add a second Sprite object, instead of the Player, this new sprite object is moving and finally if i add a third Sprite object the third one is moving. And the weird think is that i'm transforming the Vertices of the Player so why the transformation is being applied somewhere else?
       
      Take a look at my code:
      Sprite Class
      (You mostly need to see the Constructor, the Render Method and the Move Method)
      #include "Brain.h" #include <glm/gtc/matrix_transform.hpp> #include <vector> struct Sprite::Implementation { //Position. struct pos pos; //Tag. std::string tag; //Texture. Texture *texture; //Model matrix. glm::mat4 model; //Vertex Array Object. VertexArray *vao; //Vertex Buffer Object. VertexBuffer *vbo; //Layout. VertexBufferLayout *layout; //Index Buffer Object. IndexBuffer *ibo; //Shader. Shader *program; //Brains. std::vector<Brain *> brains; //Deconstructor. ~Implementation(); }; Sprite::Sprite(std::string image_path, std::string tag, float x, float y) { //Create Pointer To Implementaion. m_Impl = new Implementation(); //Set the Position of the Sprite object. m_Impl->pos.x = x; m_Impl->pos.y = y; //Set the tag. m_Impl->tag = tag; //Create The Texture. m_Impl->texture = new Texture(image_path); //Initialize the model Matrix. m_Impl->model = glm::mat4(1.0f); //Get the Width and the Height of the Texture. int width = m_Impl->texture->GetWidth(); int height = m_Impl->texture->GetHeight(); //Create the Verticies. float verticies[] = { //Positions //Texture Coordinates. x, y, 0.0f, 0.0f, x + width, y, 1.0f, 0.0f, x + width, y + height, 1.0f, 1.0f, x, y + height, 0.0f, 1.0f }; //Create the Indicies. unsigned int indicies[] = { 0, 1, 2, 2, 3, 0 }; //Create Vertex Array. m_Impl->vao = new VertexArray(); //Create the Vertex Buffer. m_Impl->vbo = new VertexBuffer((void *)verticies, sizeof(verticies)); //Create The Layout. m_Impl->layout = new VertexBufferLayout(); m_Impl->layout->PushFloat(2); m_Impl->layout->PushFloat(2); m_Impl->vao->AddBuffer(m_Impl->vbo, m_Impl->layout); //Create the Index Buffer. m_Impl->ibo = new IndexBuffer(indicies, 6); //Create the new shader. m_Impl->program = new Shader("Shaders/SpriteShader.shader"); } //Render. void Sprite::Render(Window * window) { //Create the projection Matrix based on the current window width and height. glm::mat4 proj = glm::ortho(0.0f, (float)window->GetWidth(), 0.0f, (float)window->GetHeight(), -1.0f, 1.0f); //Set the MVP Uniform. m_Impl->program->setUniformMat4f("u_MVP", proj * m_Impl->model); //Run All The Brains (Scripts) of this game object (sprite). for (unsigned int i = 0; i < m_Impl->brains.size(); i++) { //Get Current Brain. Brain *brain = m_Impl->brains[i]; //Call the start function only once! if (brain->GetStart()) { brain->SetStart(false); brain->Start(); } //Call the update function every frame. brain->Update(); } //Render. window->GetRenderer()->Draw(m_Impl->vao, m_Impl->ibo, m_Impl->texture, m_Impl->program); } void Sprite::Move(float speed, bool left, bool right, bool up, bool down) { if (left) { m_Impl->pos.x -= speed; m_Impl->model = glm::translate(m_Impl->model, glm::vec3(-speed, 0, 0)); } if (right) { m_Impl->pos.x += speed; m_Impl->model = glm::translate(m_Impl->model, glm::vec3(speed, 0, 0)); } if (up) { m_Impl->pos.y += speed; m_Impl->model = glm::translate(m_Impl->model, glm::vec3(0, speed, 0)); } if (down) { m_Impl->pos.y -= speed; m_Impl->model = glm::translate(m_Impl->model, glm::vec3(0, -speed, 0)); } } void Sprite::AddBrain(Brain * brain) { //Push back the brain object. m_Impl->brains.push_back(brain); } pos *Sprite::GetPos() { return &m_Impl->pos; } std::string Sprite::GetTag() { return m_Impl->tag; } int Sprite::GetWidth() { return m_Impl->texture->GetWidth(); } int Sprite::GetHeight() { return m_Impl->texture->GetHeight(); } Sprite::~Sprite() { delete m_Impl; } //Implementation Deconstructor. Sprite::Implementation::~Implementation() { delete texture; delete vao; delete vbo; delete layout; delete ibo; delete program; }  
      Renderer Class
      #include "Renderer.h" #include "Error.h" Renderer::Renderer() { } Renderer::~Renderer() { } void Renderer::Draw(VertexArray * vao, IndexBuffer * ibo, Texture *texture, Shader * program) { vao->Bind(); ibo->Bind(); program->Bind(); if (texture != NULL) texture->Bind(); GLCall(glDrawElements(GL_TRIANGLES, ibo->GetCount(), GL_UNSIGNED_INT, NULL)); } void Renderer::Clear(float r, float g, float b) { GLCall(glClearColor(r, g, b, 1.0)); GLCall(glClear(GL_COLOR_BUFFER_BIT)); } void Renderer::Update(GLFWwindow *window) { /* Swap front and back buffers */ glfwSwapBuffers(window); /* Poll for and process events */ glfwPollEvents(); }  
      Shader Code
      #shader vertex #version 330 core layout(location = 0) in vec4 aPos; layout(location = 1) in vec2 aTexCoord; out vec2 t_TexCoord; uniform mat4 u_MVP; void main() { gl_Position = u_MVP * aPos; t_TexCoord = aTexCoord; } #shader fragment #version 330 core out vec4 aColor; in vec2 t_TexCoord; uniform sampler2D u_Texture; void main() { aColor = texture(u_Texture, t_TexCoord); } Also i'm pretty sure that every time i'm hitting the up, down, left and right arrows on the keyboard, i'm changing the model Matrix of the Player and not the others.
       
      Window Class:
      #include "Window.h" #include <GL/glew.h> #include <GLFW/glfw3.h> #include "Error.h" #include "Renderer.h" #include "Scene.h" #include "Input.h" //Global Variables. int screen_width, screen_height; //On Window Resize. void OnWindowResize(GLFWwindow *window, int width, int height); //Implementation Structure. struct Window::Implementation { //GLFW Window. GLFWwindow *GLFW_window; //Renderer. Renderer *renderer; //Delta Time. double delta_time; //Frames Per Second. int fps; //Scene. Scene *scnene; //Input. Input *input; //Deconstructor. ~Implementation(); }; //Window Constructor. Window::Window(std::string title, int width, int height) { //Initializing width and height. screen_width = width; screen_height = height; //Create Pointer To Implementation. m_Impl = new Implementation(); //Try initializing GLFW. if (!glfwInit()) { std::cout << "GLFW could not be initialized!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); exit(-1); } //Setting up OpenGL Version 3.3 Core Profile. glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); /* Create a windowed mode window and its OpenGL context */ m_Impl->GLFW_window = glfwCreateWindow(width, height, title.c_str(), NULL, NULL); if (!m_Impl->GLFW_window) { std::cout << "GLFW could not create a window!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); glfwTerminate(); exit(-1); } /* Make the window's context current */ glfwMakeContextCurrent(m_Impl->GLFW_window); //Initialize GLEW. if(glewInit() != GLEW_OK) { std::cout << "GLEW could not be initialized!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); glfwTerminate(); exit(-1); } //Enabling Blending. GLCall(glEnable(GL_BLEND)); GLCall(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)); //Setting the ViewPort. GLCall(glViewport(0, 0, width, height)); //**********Initializing Implementation**********// m_Impl->renderer = new Renderer(); m_Impl->delta_time = 0.0; m_Impl->fps = 0; m_Impl->input = new Input(this); //**********Initializing Implementation**********// //Set Frame Buffer Size Callback. glfwSetFramebufferSizeCallback(m_Impl->GLFW_window, OnWindowResize); } //Window Deconstructor. Window::~Window() { delete m_Impl; } //Window Main Loop. void Window::MainLoop() { //Time Variables. double start_time = 0, end_time = 0, old_time = 0, total_time = 0; //Frames Counter. int frames = 0; /* Loop until the user closes the window */ while (!glfwWindowShouldClose(m_Impl->GLFW_window)) { old_time = start_time; //Total time of previous frame. start_time = glfwGetTime(); //Current frame start time. //Calculate the Delta Time. m_Impl->delta_time = start_time - old_time; //Get Frames Per Second. if (total_time >= 1) { m_Impl->fps = frames; total_time = 0; frames = 0; } //Clearing The Screen. m_Impl->renderer->Clear(0, 0, 0); //Render The Scene. if (m_Impl->scnene != NULL) m_Impl->scnene->Render(this); //Updating the Screen. m_Impl->renderer->Update(m_Impl->GLFW_window); //Increasing frames counter. frames++; //End Time. end_time = glfwGetTime(); //Total time after the frame completed. total_time += end_time - start_time; } //Terminate GLFW. glfwTerminate(); } //Load Scene. void Window::LoadScene(Scene * scene) { //Set the scene. m_Impl->scnene = scene; } //Get Delta Time. double Window::GetDeltaTime() { return m_Impl->delta_time; } //Get FPS. int Window::GetFPS() { return m_Impl->fps; } //Get Width. int Window::GetWidth() { return screen_width; } //Get Height. int Window::GetHeight() { return screen_height; } //Get Input. Input * Window::GetInput() { return m_Impl->input; } Renderer * Window::GetRenderer() { return m_Impl->renderer; } GLFWwindow * Window::GetGLFWindow() { return m_Impl->GLFW_window; } //Implementation Deconstructor. Window::Implementation::~Implementation() { delete renderer; delete input; } //OnWindowResize void OnWindowResize(GLFWwindow *window, int width, int height) { screen_width = width; screen_height = height; //Updating the ViewPort. GLCall(glViewport(0, 0, width, height)); }  
      Brain Class
      #include "Brain.h" #include "Sprite.h" #include "Window.h" struct Brain::Implementation { //Just A Flag. bool started; //Window Pointer. Window *window; //Sprite Pointer. Sprite *sprite; }; Brain::Brain(Window *window, Sprite *sprite) { //Create Pointer To Implementation. m_Impl = new Implementation(); //Initialize Implementation. m_Impl->started = true; m_Impl->window = window; m_Impl->sprite = sprite; } Brain::~Brain() { //Delete Pointer To Implementation. delete m_Impl; } void Brain::Start() { } void Brain::Update() { } Window * Brain::GetWindow() { return m_Impl->window; } Sprite * Brain::GetSprite() { return m_Impl->sprite; } bool Brain::GetStart() { return m_Impl->started; } void Brain::SetStart(bool value) { m_Impl->started = value; } Script Class (Its a Brain Subclass!!!)
      #include "Script.h" Script::Script(Window *window, Sprite *sprite) : Brain(window, sprite) { } Script::~Script() { } void Script::Start() { std::cout << "Game Started!" << std::endl; } void Script::Update() { Input *input = this->GetWindow()->GetInput(); Sprite *sp = this->GetSprite(); //Move this sprite. this->GetSprite()->Move(200 * this->GetWindow()->GetDeltaTime(), input->GetKeyDown("left"), input->GetKeyDown("right"), input->GetKeyDown("up"), input->GetKeyDown("down")); std::cout << sp->GetTag().c_str() << ".x = " << sp->GetPos()->x << ", " << sp->GetTag().c_str() << ".y = " << sp->GetPos()->y << std::endl; }  
      Main:
      #include "SpaceShooterEngine.h" #include "Script.h" int main() { Window w("title", 600,600); Scene *scene = new Scene(); Sprite *player = new Sprite("Resources/Images/player.png", "Player", 100,100); Sprite *other = new Sprite("Resources/Images/cherno.png", "Other", 400, 100); Sprite *other2 = new Sprite("Resources/Images/cherno.png", "Other", 300, 400); Brain *brain = new Script(&w, player); player->AddBrain(brain); scene->AddSprite(player); scene->AddSprite(other); scene->AddSprite(other2); w.LoadScene(scene); w.MainLoop(); return 0; }  
       
      I literally can't find what is wrong. If you need more code, ask me to post it. I will also attach all the source files.
      Brain.cpp
      Error.cpp
      IndexBuffer.cpp
      Input.cpp
      Renderer.cpp
      Scene.cpp
      Shader.cpp
      Sprite.cpp
      Texture.cpp
      VertexArray.cpp
      VertexBuffer.cpp
      VertexBufferLayout.cpp
      Window.cpp
      Brain.h
      Error.h
      IndexBuffer.h
      Input.h
      Renderer.h
      Scene.h
      Shader.h
      SpaceShooterEngine.h
      Sprite.h
      Texture.h
      VertexArray.h
      VertexBuffer.h
      VertexBufferLayout.h
      Window.h
    • By Cristian Decu
      Hello fellow programmers,
      For a couple of days now i've decided to build my own planet renderer just to see how floating point precision issues
      can be tackled. As you probably imagine, i've quickly faced FPP issues when trying to render absurdly large planets.
       
      I have used the classical quadtree LOD approach;
      I've generated my grids with 33 vertices, (x: -1 to 1, y: -1 to 1, z = 0).
      Each grid is managed by a TerrainNode class that, depending on the side it represents (top, bottom, left right, front, back),
      creates a special rotation-translation matrix that moves and rotates the grid away from the origin so that when i finally
      normalize all the vertices on my vertex shader i can get a perfect sphere.
      T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, 1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(180.0), glm::dvec3(1.0, 0.0, 0.0)); sides[0] = new TerrainNode(1.0, radius, T * R, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_FRONT)); T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, -1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(0.0), glm::dvec3(1.0, 0.0, 0.0)); sides[1] = new TerrainNode(1.0, radius, R * T, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_BACK)); // So on and so forth for the rest of the sides As you can see, for the front side grid, i rotate it 180 degrees to make it face the camera and push it towards the eye;
      the back side is handled almost the same way only that i don't need to rotate it but simply push it away from the eye.
      The same technique is applied for the rest of the faces (obviously, with the proper rotations / translations).
      The matrix that result from the multiplication of R and T (in that particular order) is send to my vertex shader as `r_Grid'.
      // spherify vec3 V = normalize((r_Grid * vec4(r_Vertex, 1.0)).xyz); gl_Position = r_ModelViewProjection * vec4(V, 1.0); The `r_ModelViewProjection' matrix is generated on the CPU in this manner.
      // No the most efficient way, but it works. glm::dmat4 Camera::getMatrix() { // Create the view matrix // Roll, Yaw and Pitch are all quaternions. glm::dmat4 View = glm::toMat4(Roll) * glm::toMat4(Pitch) * glm::toMat4(Yaw); // The model matrix is generated by translating in the oposite direction of the camera. glm::dmat4 Model = glm::translate(glm::dmat4(1.0), -Position); // Projection = glm::perspective(fovY, aspect, zNear, zFar); // zNear = 0.1, zFar = 1.0995116e12 return Projection * View * Model; } I managed to get rid of z-fighting by using a technique called Logarithmic Depth Buffer described in this article; it works amazingly well, no z-fighting at all, at least not visible.
      Each frame i'm rendering each node by sending the generated matrices this way.
      // set the r_ModelViewProjection uniform // Sneak in the mRadiusMatrix which is a matrix that contains the radius of my planet. Shader::setUniform(0, Camera::getInstance()->getMatrix() * mRadiusMatrix); // set the r_Grid matrix uniform i created earlier. Shader::setUniform(1, r_Grid); grid->render(); My planet's radius is around 6400000.0 units, absurdly large, but that's what i really want to achieve;
      Everything works well, the node's split and merge as you'd expect, however whenever i get close to the surface
      of the planet the rounding errors start to kick in giving me that lovely stairs effect.
      I've read that if i could render each grid relative to the camera i could get better precision on the surface, effectively
      getting rid of those rounding errors.
       
      My question is how can i achieve this relative to camera rendering in my scenario here?
      I know that i have to do most of the work on the CPU with double, and that's exactly what i'm doing.
      I only use double on the CPU side where i also do most of the matrix multiplications.
      As you can see from my vertex shader i only do the usual r_ModelViewProjection * (some vertex coords).
       
      Thank you for your suggestions!
       
  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

Participate in the game development conversation and more when you create an account on GameDev.net!

Sign me up!