Cfrgtkky

So I have Been trying to implement Freetype to my 2D Engine and the text actually renders but only for one second or less and then it dissappears, already made sure that the render function is still been called, have no idea what could be wrong. Also it only renders the text on the Update function, when I try to render on Render it just wont pop up (this is driving me crazy, the functions are being called one after the other and nothing is modified).

Example:

TextRenderer* Text;



int main() {

    //OpenGL stuff

    Text = new Text(1920, 1080);

    Text->Load("fonts/arial.ttf",  24);

    while(window.isOpen) {

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glfwPollEvents();

        Update();

        Render();

        glfwSwapBuffers(m_window);

    }

}



void Update() {

    //Works for half a second

    Text->RenderText("Hello World", 200, 300, 1.0f);

}

void Render() {

    //Just wont work

    Text->RenderText("Hello World", 200, 300, 1.0f);

}

TextRenderer.cpp:

TextRenderer::TextRenderer(GLuint width, GLuint height)

{

    // Load and configure shader

    this->TextShader = Resources::LoadShader("shaders/text.vs", "shaders/text.frag", "text");

    this->TextShader.SetMatrix4("projection", glm::ortho(0.0f, static_cast<GLfloat>(width), static_cast<GLfloat>(height), 0.0f), GL_TRUE);

    this->TextShader.SetInteger("text", 0);

    // Configure VAO/VBO for texture quads

    glGenVertexArrays(1, &this->VAO);

    glGenBuffers(1, &this->VBO);

    glBindVertexArray(this->VAO);

    glBindBuffer(GL_ARRAY_BUFFER, this->VBO);

    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 6 * 4, NULL, GL_DYNAMIC_DRAW);

    glEnableVertexAttribArray(0);

    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), 0);

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glBindVertexArray(0);

}



void TextRenderer::Load(std::string font, GLuint fontSize)

    {

        // First clear the previously loaded Characters

        this->Characters.clear();

        // Then initialize and load the FreeType library

        FT_Library ft;

        if (FT_Init_FreeType(&ft)) // All functions return a value different than 0 whenever an error occurred

            std::cout << "ERROR::FREETYPE: Could not init FreeType Library" << std::endl;

        // Load font as face

        FT_Face face;

        if (FT_New_Face(ft, font.c_str(), 0, &face))

            std::cout << "ERROR::FREETYPE: Failed to load font" << std::endl;

        // Set size to load glyphs as

        FT_Set_Pixel_Sizes(face, 0, fontSize);

        // Disable byte-alignment restriction

        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

        // Then for the first 128 ASCII characters, pre-load/compile their characters and store them

        for (GLubyte c = 0; c < 128; c++) // lol see what I did there 

        {

            // Load character glyph 

            if (FT_Load_Char(face, c, FT_LOAD_RENDER))

            {

                std::cout << "ERROR::FREETYTPE: Failed to load Glyph" << std::endl;

                continue;

            }

            // Generate texture

            GLuint texture;

            glGenTextures(1, &texture);

            glBindTexture(GL_TEXTURE_2D, texture);

            glTexImage2D(

                GL_TEXTURE_2D,

                0,

                GL_RED,

                face->glyph->bitmap.width,

                face->glyph->bitmap.rows,

                0,

                GL_RED,

                GL_UNSIGNED_BYTE,

                face->glyph->bitmap.buffer

            );

            // Set texture options

            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);



            // Now store character for later use

            Character character = {

                texture,

                glm::ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),

                glm::ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),

                face->glyph->advance.x

            };

            Characters.insert(std::pair<GLchar, Character>(c, character));

        }

        glBindTexture(GL_TEXTURE_2D, 0);

        // Destroy FreeType once we're finished

        FT_Done_Face(face);

        FT_Done_FreeType(ft);

    }



void TextRenderer::RenderText(std::string text, GLfloat x, GLfloat y, GLfloat scale, glm::vec3 color)

{

    // Activate corresponding render state  

    this->TextShader.Use();

    this->TextShader.SetVector3f("textColor", color);

    glActiveTexture(GL_TEXTURE0);

    glBindVertexArray(this->VAO);



    // Iterate through all characters

    std::string::const_iterator c;

    for (c = text.begin(); c != text.end(); c++)

    {

        Character ch = Characters[*c];



        GLfloat xpos = x + ch.Bearing.x * scale;



        GLfloat ypos = y + (this->Characters['H'].Bearing.y - ch.Bearing.y) * scale;



        GLfloat w = ch.Size.x * scale;

        GLfloat h = ch.Size.y * scale;

        // Update VBO for each character

        GLfloat vertices[6][4] = {

            { xpos,     ypos + h,   0.0, 1.0 },

            { xpos + w, ypos,       1.0, 0.0 },

            { xpos,     ypos,       0.0, 0.0 },



            { xpos,     ypos + h,   0.0, 1.0 },

            { xpos + w, ypos + h,   1.0, 1.0 },

            { xpos + w, ypos,       1.0, 0.0 }

        };

        // Render glyph texture over quad

        glBindTexture(GL_TEXTURE_2D, ch.TextureID);

        // Update content of VBO memory

        glBindBuffer(GL_ARRAY_BUFFER, this->VBO);

        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices); // Be sure to use glBufferSubData and not glBufferData



        glBindBuffer(GL_ARRAY_BUFFER, 0);

        // Render quad

        glDrawArrays(GL_TRIANGLES, 0, 6);

        // Now advance cursors for next glyph

        x += (ch.Advance >> 6) * scale; // Bitshift by 6 to get value in pixels (1/64th times 2^6 = 64)

    }

    glBindVertexArray(0);

    glBindTexture(GL_TEXTURE_2D, 0);

}

@Aether I got your engine runnning and while I don't yet have the answer as to why this is occuring (haven't had a thorough look yet) I can tell you that the issue does not occur if you don't update the camera. My gut feeling on this is that you have moved the camera or the text so that it is no longer in view but I'm hoping to add more to this when I can.

void Sandbox::Init() {



    AETHER_CLIENT_TRACE("Initialized LifeSandbox");

    GameManager::GameSpeed = 1;



    Resources::LoadTexture("textures/default.png", "default");

    Resources::LoadTexture("textures/emoji.png", "emoji");

    Resources::LoadShader("shaders/spriteVertexShader.bin", "shaders/spriteFragmentShader.bin", "sprite");

    Renderer = new Renderer2D(Resources::GetShader("sprite"));

    Text->Load("fonts/arial.TTF", 24);

    MainCamera = new Camera();  

}



void Sandbox::Update() 

{       

    //MainCamera->Update(iVec2(0.0f, 0.0f));

}



void Sandbox::Render() 

{

  //Works fine

  Text->RenderText("Press ENTER to start", 0, 0, 1.0, iVec3(2.0f));

}