Csabi
Csabi

Reputation: 3043

.gif image display using OpenGl

Can I display *.gif image in openGL? I want to use it like texture of glQuad display list.

glNewList(base+loop,GL_COMPILE);                // Start Building A List
            glBegin(GL_QUADS);                          // Use A Quad For Each Character
                glTexCoord2f(cx,1-cy-0.0625f);          // Texture Coord (Bottom Left)
                glVertex2i(0,0);                        // Vertex Coord (Bottom Left)
                glTexCoord2f(cx+0.0625f,1-cy-0.0625f);  // Texture Coord (Bottom Right)
                glVertex2i(16,0);                       // Vertex Coord (Bottom Right)
                glTexCoord2f(cx+0.0625f,1-cy);          // Texture Coord (Top Right)
                glVertex2i(16,16);                      // Vertex Coord (Top Right)
                glTexCoord2f(cx,1-cy);                  // Texture Coord (Top Left)
                glVertex2i(0,16);                       // Vertex Coord (Top Left)
            glEnd();                                    // Done Building Our Quad (Character)
            glTranslated(10,0,0);                       // Move To The Right Of The Character
        glEndList();    

Thx

I m using yhis libraries

#include <windows.h>        // Header File For Windows
#include <stdio.h>          // Header File For Standard Input/Output
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <sstream>
//#include "glut.h"
#include <gl\gl.h>          // Header File For The OpenGL32 Library
#include <gl\glu.h>         // Header File For The GLu32 Library
#include <gl\glut.h>    
#include <gl\glaux.h>   

Upvotes: 4

Views: 11276

Answers (2)

shybovycha
shybovycha

Reputation: 12265

I recommend you to use SFML - it supports lot of image formats and image loading/processing is made simple with it. Here's an example application with textured cube using SFML:

#include <SFML/Graphics.hpp>
#include <iostream>

int main()
{
    // Create main window
    sf::RenderWindow App(sf::VideoMode(800, 600), "SFML OpenGL");
    App.PreserveOpenGLStates(true);

    // Create a sprite for the background
    sf::Image BackgroundImage;
    if (!BackgroundImage.LoadFromFile("datas/opengl/background.jpg"))
        return EXIT_FAILURE;
    sf::Sprite Background(BackgroundImage);

    // Load an OpenGL texture.
    // We could directly use a sf::Image as an OpenGL texture (with its Bind() member function),
    // but here we want more control on it (generate mipmaps, ...) so we create a new one
    GLuint Texture = 0;
    {
        sf::Image Image;
        if (!Image.LoadFromFile("datas/opengl/texture.jpg"))
            return EXIT_FAILURE;
        glGenTextures(1, &Texture);
        glBindTexture(GL_TEXTURE_2D, Texture);
        gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGBA, Image.GetWidth(), Image.GetHeight(), GL_RGBA, GL_UNSIGNED_BYTE, Image.GetPixelsPtr());
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    }

    // Enable Z-buffer read and write
    glEnable(GL_DEPTH_TEST);
    glDepthMask(GL_TRUE);
    glClearDepth(1.f);

    // Setup a perspective projection
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(90.f, 1.f, 1.f, 500.f);

    // Bind our texture
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, Texture);
    glColor4f(1.f, 1.f, 1.f, 1.f);

    // Create a clock for measuring the time elapsed
    sf::Clock Clock;

    // Start game loop
    while (App.IsOpened())
    {
        // Process events
        sf::Event Event;
        while (App.GetEvent(Event))
        {
            // Close window : exit
            if (Event.Type == sf::Event::Closed)
                App.Close();

            // Escape key : exit
            if ((Event.Type == sf::Event::KeyPressed) && (Event.Key.Code == sf::Key::Escape))
                App.Close();

            // Adjust the viewport when the window is resized
            if (Event.Type == sf::Event::Resized)
                glViewport(0, 0, Event.Size.Width, Event.Size.Height);
         }

        // Draw background
        App.Draw(Background);

        // Clear depth buffer
        glClear(GL_DEPTH_BUFFER_BIT);

        // Apply some transformations
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        glTranslatef(0.f, 0.f, -200.f);
        glRotatef(Clock.GetElapsedTime() * 50, 1.f, 0.f, 0.f);
        glRotatef(Clock.GetElapsedTime() * 30, 0.f, 1.f, 0.f);
        glRotatef(Clock.GetElapsedTime() * 90, 0.f, 0.f, 1.f);

        // Draw a cube
        glBegin(GL_QUADS);

            glTexCoord2f(0, 0); glVertex3f(-50.f, -50.f, -50.f);
            glTexCoord2f(0, 1); glVertex3f(-50.f,  50.f, -50.f);
            glTexCoord2f(1, 1); glVertex3f( 50.f,  50.f, -50.f);
            glTexCoord2f(1, 0); glVertex3f( 50.f, -50.f, -50.f);

            glTexCoord2f(0, 0); glVertex3f(-50.f, -50.f, 50.f);
            glTexCoord2f(0, 1); glVertex3f(-50.f,  50.f, 50.f);
            glTexCoord2f(1, 1); glVertex3f( 50.f,  50.f, 50.f);
            glTexCoord2f(1, 0); glVertex3f( 50.f, -50.f, 50.f);

            glTexCoord2f(0, 0); glVertex3f(-50.f, -50.f, -50.f);
            glTexCoord2f(0, 1); glVertex3f(-50.f,  50.f, -50.f);
            glTexCoord2f(1, 1); glVertex3f(-50.f,  50.f,  50.f);
            glTexCoord2f(1, 0); glVertex3f(-50.f, -50.f,  50.f);

            glTexCoord2f(0, 0); glVertex3f(50.f, -50.f, -50.f);
            glTexCoord2f(0, 1); glVertex3f(50.f,  50.f, -50.f);
            glTexCoord2f(1, 1); glVertex3f(50.f,  50.f,  50.f);
            glTexCoord2f(1, 0); glVertex3f(50.f, -50.f,  50.f);

            glTexCoord2f(0, 1); glVertex3f(-50.f, -50.f,  50.f);
            glTexCoord2f(0, 0); glVertex3f(-50.f, -50.f, -50.f);
            glTexCoord2f(1, 0); glVertex3f( 50.f, -50.f, -50.f);
            glTexCoord2f(1, 1); glVertex3f( 50.f, -50.f,  50.f);

            glTexCoord2f(0, 1); glVertex3f(-50.f, 50.f,  50.f);
            glTexCoord2f(0, 0); glVertex3f(-50.f, 50.f, -50.f);
            glTexCoord2f(1, 0); glVertex3f( 50.f, 50.f, -50.f);
            glTexCoord2f(1, 1); glVertex3f( 50.f, 50.f,  50.f);

        glEnd();

        // Draw some text on top of our OpenGL object
        sf::String Text("This is a rotating cube");
        Text.SetPosition(250.f, 300.f);
        Text.SetColor(sf::Color(128, 0, 128));
        App.Draw(Text);

        // Finally, display the rendered frame on screen
        App.Display();
    }

    // Don't forget to destroy our texture
    glDeleteTextures(1, &Texture);

    return EXIT_SUCCESS;
}

Note: And do not use glaux - it is terribly lost in time.

Note: demo uses .jpg image format. This one is better than .gif, because it is more lightweight and, afaik, widespreaded and easier to implement in application.

Upvotes: 2

Jerry Coffin
Jerry Coffin

Reputation: 490338

It's kind of overkill if you just want to support GIF, but DevIL supports GIF (among many others). There are lighter solutions around as well. Alternatively, you can get the GIF spec, and write it yourself (makes a nice, relaxing afternoon project as I recall).

Upvotes: 1

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