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1

General discussions / Re: SFML 2 and its new website released

« on: May 01, 2013, 04:37:27 pm »

Congratulations! Wish I had more time to program, and use your beautiful library!

2

SFML projects / Re: Pioneers

« on: October 02, 2012, 07:13:50 pm »

Congrats, I enjoy seeing a fun game develop.

3

Graphics / Same problem with May 2011 drivers

« on: June 14, 2011, 03:40:31 pm »

After Windows auto-updated my driver (OK I foolishly checked the box to allow it), my application hangs on the RenderWindow, as well as the sample application. So, still not fixed by ATI

Here are instructions I found for uninstalling ATI drivers in Win7:
http://support.amd.com/us/kbarticles/Pages/GPU57RemoveOldGraphicsDrivers.aspx#windows7

I still had to go to Device Manager, ATI properties, and click "Uninstall" to completely rid myself of the driver. Have your old driver ready to install.

Here are older ATI drivers for Vista/Win7 64-bit.
http://support.amd.com/us/gpudownload/windows/previous/Pages/radeonaiw_vista64.aspx

You can get them for other operating systems by searching for the current version, then clicking the small "Previous Drivers" link.

4

Graphics / I think OpenGL is working fine

« on: November 15, 2010, 07:03:18 pm »

I put some debugging in my code to dump the raw bytes of the image after I load it. I can see that the Alpha channel starts off at 0, and as I keep blitting images eventually I'll get some FF in there. It corresponds to what's being displayed.

So, I believe it's an issue with how I'm blitting or how I'm loading the PNG file. More investigation to follow

5

Graphics / Alpha test for textures not working [Solved]

« on: November 15, 2010, 08:21:19 am »

I fixed this, the solution was to add "ilDisable(IL_BLIT_BLEND)". Apparently the ilBlit function would combine alpha channels by default, instead of overwriting them.

Any other advice for cleaning up my code is welcome, though

=========
I haven't used OpenGL before this week, I'm probably making an obvious mistake.

I'm using DevIL to load a PNG file with alpha channel, blit a piece of the file to another texture, and use that texture to draw 6 faces of a cube.

It starts off black (I think transparent), but as I blit other textures a lot by holding down the arrow key, I'll see the textures with random transparent parts. The scary thing is, if I free the DevIL image after loading to openGL with glTexImage2D, it will stay transparent. I think it's only corrupted memory that is letting me see anything!

Here's the complete code...

Code: [Select]


//SFML test app

//SFML
#include <SFML/System.hpp>
#include <SFML/Window.hpp>

//DevIL
#include <IL/il.h>
#include <IL/ilu.h>

//STL
#include <iostream>
#include <string>

using std::cout;
using std::cerr;
using std::endl;
using std::string;

const string imageFilename("terrain.png");

//openGL image
GLuint image;
size_t texmap_X = 1;
size_t texmap_Y = 3;
const size_t texmap_SIZE = 16;
//Start

//draw cube faces
void drawCubes() {
    
    //Draw cube
    glBegin(GL_QUADS);
    
    //x: A = -50, B = 50
    //y: C = -50, D = 50
    //z: E = -50, F = 50
    //A
    glTexCoord2i(0,0); glVertex3i( -16, -16, -16);  //Lower left
    glTexCoord2i(1,0); glVertex3i( -16, -16,  16);  //Lower right
    glTexCoord2i(1,1); glVertex3i( -16,  16,  16);  //Top right
    glTexCoord2i(0,1); glVertex3i( -16,  16, -16);  //Top left

    //B
    glTexCoord2i(0,0); glVertex3i(  16, -16,  16);  //Lower left:  BCF
    glTexCoord2i(1,0); glVertex3i(  16, -16, -16);  //Lower right: BCE
    glTexCoord2i(1,1); glVertex3i(  16,  16, -16);  //Top right:   BDE
    glTexCoord2i(0,1); glVertex3i(  16,  16,  16);  //Top left:    BDF
    
    //C
    glTexCoord2i(0,0); glVertex3i( -16, -16, -16);  //Lower left:  ACE
    glTexCoord2i(1,0); glVertex3i(  16, -16, -16);  //Lower right: BCE
    glTexCoord2i(1,1); glVertex3i(  16, -16,  16);  //Top right:   BCF
    glTexCoord2i(0,1); glVertex3i( -16, -16,  16);  //Top left:    ACF
    
    //D
    glTexCoord2i(0,0); glVertex3i( -16,  16,  16);  //Lower left:  ADF
    glTexCoord2i(1,0); glVertex3i(  16,  16,  16);  //Lower right: BDF
    glTexCoord2i(1,1); glVertex3i(  16,  16, -16);  //Top right:   BDE
    glTexCoord2i(0,1); glVertex3i( -16,  16, -16);  //Top left:    ADE
    
    //E
    glTexCoord2i(0,0); glVertex3i(  16, -16, -16);  //Lower left:  BCE
    glTexCoord2i(1,0); glVertex3i( -16, -16, -16);  //Lower right: ACE
    glTexCoord2i(1,1); glVertex3i( -16,  16, -16);  //Top right:   ADE
    glTexCoord2i(0,1); glVertex3i(  16,  16, -16);  //Top left:    BDE
    
    //F
    glTexCoord2i(0,0); glVertex3i( -16, -16,  16);  //Lower left:  ACF
    glTexCoord2i(1,0); glVertex3i(  16, -16,  16);  //Lower right: BCF
    glTexCoord2i(1,1); glVertex3i(  16,  16,  16);  //Top right:   BDF
    glTexCoord2i(0,1); glVertex3i( -16,  16,  16);  //Top left:    ADF

    glEnd();
}


//Blit from texture map to current OpenGL texture
ILuint blitTexture( ILuint texmap, ILuint SrcX, ILuint SrcY, ILuint Width, ILuint Height) {
    //Take out a specific block from the texture grid (Blit)
    ILuint il_blocktex;
    ilGenImages(1, &il_blocktex);
    ilBindImage(il_blocktex);
    ilTexImage( Width, Height, 1, 4, IL_RGBA, IL_UNSIGNED_BYTE, NULL);

    //Blit the rectangle from texmap to il_blocktex
    ilBlit( texmap, 0, 0, 0, SrcX, SrcY, 0, Width, Height, 1);

    glBindTexture(GL_TEXTURE_2D, image);
    
    //Set zoom filters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);  //GL_LINEAR?
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    //Copy current DevIL image to OpenGL image
    glTexImage2D(GL_TEXTURE_2D, 0, ilGetInteger(IL_IMAGE_BPP),
        ilGetInteger(IL_IMAGE_WIDTH), ilGetInteger(IL_IMAGE_HEIGHT), 0,
        ilGetInteger(IL_IMAGE_FORMAT), GL_UNSIGNED_BYTE, ilGetData());

    //ilDeleteImages(1, &il_blocktex);  //free memory used by DevIL
    return il_blocktex;
}


//Set up buffer, perspective, blah blah blah
void startOpenGL() {
    //OPENGL setup in SFML
    //Set color and depth clear value
    glClearDepth(1.0f);
    glClearColor(0.f, 0.f, 0.f, 1.f);

    // Enable Z-buffer read and write
    glEnable(GL_DEPTH_TEST);
    glDepthMask(GL_TRUE);

    //Enable texture mapping
    glViewport(0, 0, 800, 600);
    glEnable(GL_TEXTURE_2D);
    
    //Transparency in textures
    glEnable(GL_ALPHA_TEST);
    glAlphaFunc(GL_GREATER, 0.5f);

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

    //Move camera
    glMatrixMode(GL_MODELVIEW);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
    glLoadIdentity();

    //Create OpenGL texture
    glGenTextures(1, &image);
}


//Load the image file
ILuint loadImageFile() {
    ILuint il_texmap;
    ilGenImages(1, &il_texmap);
    ilBindImage(il_texmap);

    if (ilLoad(IL_PNG, imageFilename.c_str())) {
      
        //Convert image to RGBA
        if (!ilConvertImage(IL_RGBA, IL_UNSIGNED_BYTE)) {
            cerr << "Error converting " << imageFilename << endl;
            ILenum ilErrorCode = 0;
            while ( (ilErrorCode = ilGetError()) != IL_NO_ERROR) {
                cerr << "Error code " << ilErrorCode << endl;
            }
            return 0;
        }
    
    } else {
        cerr << "Error loading " << imageFilename << endl;
        ILenum ilErrorCode = 0;
        while ( (ilErrorCode = ilGetError()) != IL_NO_ERROR) {
            cerr << "Error code " << ilErrorCode << endl;
        }
        return 0;
    }

    return il_texmap;
}

int main()
{
    //Compare devIL DLL version to header version
    if (ilGetInteger(IL_VERSION_NUM) < IL_VERSION) {
        cerr << "devIL wrong DLL version" << endl;
        return 1;
    }
  
    //SFML variables
    sf::Clock Clock;
    sf::WindowSettings Settings;
    Settings.DepthBits = 24;
    Settings.StencilBits = 8;
    Settings.AntialiasingLevel = 2;

    //Create the program window, with settings
    sf::Window App(sf::VideoMode(800, 600, 32),
        "SFML OpenGL", sf::Style::Close, Settings);

    //Initialize OpenGL
    startOpenGL();

    //Start DevIL
    ilInit();

    //Load terrain image map
    ILuint il_texmap = loadImageFile();
    if (il_texmap == 0) {
        return 0;   //error, exit program
    }
    
    //Pick a texture
    blitTexture( il_texmap, texmap_X * texmap_SIZE, texmap_Y * texmap_SIZE,
        texmap_SIZE, texmap_SIZE);

    //Event loop    
    sf::Event Event;
    bool Running = true;
    while (Running && App.IsOpened()) {
      
        //Set window
        App.SetActive();

        //Clear window
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        
        //Move camera
        glTranslatef(0, -30, -100);    

        //Rotate camera
        glRotatef(Clock.GetElapsedTime() * 2, 1, 0, 0);    //yaw
        glRotatef(Clock.GetElapsedTime() * 30, 0, 1, 0);    //Rotate about Y axis
        //glRotatef(Clock.GetElapsedTime() * 90, 0, 0, 1);    //roll

        drawCubes();
        
        //Display the rendered frame
        App.Display();

        //Check events  
        while (App.GetEvent(Event))
        {
            switch( Event.Type) {
                case sf::Event::Resized:
                    glViewport(0,0, Event.Size.Width, Event.Size.Height);
                    break;
                case sf::Event::KeyPressed:
                    switch ( Event.Key.Code) {
                        case sf::Key::Escape:
                            Running = false;
                            break;
                        case sf::Key::Up:
                            texmap_Y = (texmap_Y - 1) % 16;
                            blitTexture( il_texmap, texmap_X * texmap_SIZE,
                                texmap_Y * texmap_SIZE, texmap_SIZE, texmap_SIZE);
                            break;
                        case sf::Key::Down:
                            texmap_Y = (texmap_Y + 1) % 16;
                            blitTexture( il_texmap, texmap_X * texmap_SIZE,
                                texmap_Y * texmap_SIZE, texmap_SIZE, texmap_SIZE);
                            break;
                        case sf::Key::Left:
                            texmap_X = (texmap_X - 1) % 16;
                            blitTexture( il_texmap, texmap_X * texmap_SIZE,
                                texmap_Y * texmap_SIZE, texmap_SIZE, texmap_SIZE);
                            break;
                        case sf::Key::Right:
                            texmap_X = (texmap_X + 1) % 16;
                            blitTexture( il_texmap, texmap_X * texmap_SIZE,
                                texmap_Y * texmap_SIZE, texmap_SIZE, texmap_SIZE);
                            break;
                        default:
                            break;
                    }
                    break;
                default:
                    break;
            }
        }
    }
    
    return 0;
    
}

How I compile: