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About CruzWoman

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  1. Hello, I'm new to SDL and also new to audioprocessing and have problems by generating 3D sound. I'using SDL_Mixer for the sound output and I'm trying to make 3D sound by convolution of a Mix_Chunk with a head related transfer function (HRTF). I tried it by registering an effect and make the convolution with the hrtf in the callback function of the effect. But I got no 3D sound, just the originally sound. Then I tried to make the convolution before playing the sound. I make the convolution of the HRTF directly with the Mix_Chunk->abuf. But when I play the sound, there is only noise...? Is there a possibility to make 3D sound with my approach at all? I've loaded my wav file in Matlab and compared it with my loaded wav file by using Mix_LoadWav and wrote it in a .txt file. The data is not the same...? Here's my convolution of the second approach (Mix_Chunk with HRTF): Mix_Chunk* PlaySDLAudio::makeConvolution(LeftRightHRTF myHRTFs, Mix_Chunk* audioChunk){ short* Y; short* HL; short* HR; int m = audioChunk->alen/2;// ? alen in byte, so /2 because short 16 bit = 2 byte ? int n = myHRTFs.nTaps; short* X = (short*)audioChunk->abuf; HL = new short[n+m]; HR = new short[n+m]; Y = new short[n+m-1]; for( int i = 0 ; i < n; i++ ){ HL = *myHRTFs.leftHRTF; myHRTFs.leftHRTF++; HR = *myHRTFs.rightHRTF; myHRTFs.rightHRTF++; } for ( int i = n; i < n+m; i++ ){//fill rest with 0 HL = 0; HR = 0; } //convolution for ( int i = 0; i < (n+m-1)/2; i++ ) { Y[i*2] = 0; Y[i*2+1] = 0; for ( int j = 0; j < m/2; j++ ) { if (i-j>=0){ Y[i*2] = Y[i*2] + X[j*2] * HL[i-j]; Y[i*2+1] = Y[i*2+1] + X[j*2+1] * HR[i-j]; } } } //load result in new Mix_Chunk Mix_Chunk *wave_chunk; if(!(wave_chunk=Mix_QuickLoad_RAW((Uint8*)Y,m+n))) { printf("Mix_QuickLoad_WAV: %s\n", Mix_GetError());// handle error } return wave_chunk; } I hope that someone has an idea where's my mistake or knows whether my first or second approach is a dead-end road... Thanks a lot. Greetings.
  2. CruzWoman

    Drawing diagonal lines with SDL

    Hello, everything works now. I use the function lineRGBA from SDL_gfx for now to draw a horizontal line. Hope it'll be not too slow, but I guess it'll be ok. Thanks for your help. Greetings.
  3. CruzWoman

    Drawing diagonal lines with SDL

    Thanks for all replies. I got the SDL_gfx compiled I got a diagonal line when compiling the Release Version, but in Debug mode I got an error (LINK : fatal error LNK1104: Datei "SDL_gfx.lib" kann nicht geöffnet werden.(=>could not open file "SDL_gfx.lib")) The configuration for Debug and Release seem to be the same. @ zacaj: I tried your lib-file, but got the same error in Debug mode... Thanks for sharing it I guess it's a problem with my preferences. Tomorrow I'll go on... In germany it's late and my kids will wake me up early in the morning. Greetings and good night for now.
  4. CruzWoman

    Drawing diagonal lines with SDL

    Thanks for your reply. Do you use SDL_gfx? I tried to compile it with VC++ 2010 Express, but got compile errors. I tried SDL_draw lib too, but I got an uncaught exception while running my program with SDL_draw lib. And the debugger shows me that the problem was in der SDL_draw code... I'll try to compile SDL_gfx once more. I guess it's just a problem with setting the paths or with the linker... If someone knows why my code above only draws horizontal lines, feel free to give me a hint. Greetings.
  5. Hello, I tried to draw a diagonal line with SDL, but I only get a dashed horizontal line. I have no idea what's the problem. I tried a simple algorithm (commented out) and then I found some soucecode for the bresenham algorithm. Both draw only dashed horizontal lines (the first and half of the second line of the surface) [source lang="cpp"]void ProcessSDL::DrawLine(SDL_Surface *screen, int x1, int y1, int x2, int y2, Uint8 r, Uint8 g, Uint8 b) { //simple algorithm /*double x = x2 - x1; double y = y2 - y1; double length = sqrt( x*x + y*y ); double addx = x / length; double addy = y / length; x = x1; y = y1; if( SDL_MUSTLOCK( m_pScreen ) ) { SDL_LockSurface( m_pScreen ); } for(double i = 0; i < length; i += 1) { setSdlPixel( screen, (int)x, (int)y, c_green); x += addx; y += addy; } if( SDL_MUSTLOCK( m_pScreen ) ) { SDL_UnlockSurface( m_pScreen ); } SDL_Flip(screen);*/ bresenham_line(screen, x1, y1, x2, y2, c_green); SDL_Flip(screen); } void ProcessSDL::bresenham_line(SDL_Surface *screen, Uint32 x1, Uint32 y1, Uint32 x2, Uint32 y2, Uint32 color) { int lg_delta; int sh_delta; int cycle; int lg_step; int sh_step; lg_delta = x2 - x1; sh_delta = y2 - y1; lg_step = SGN(lg_delta); lg_delta = ABS(lg_delta); sh_step = SGN(sh_delta); sh_delta = ABS(sh_delta); if (sh_delta < lg_delta) { cycle = lg_delta >> 1; while (x1 != x2) { setSdlPixel(screen, x1, y1, color); cycle += sh_delta; if (cycle > lg_delta) { cycle -= lg_delta; y1 += sh_step; } x1 += lg_step; } setSdlPixel(screen, x1, y1, color); } cycle = sh_delta >> 1; while (y1 != y2) { setSdlPixel(screen, x1, y1, color); cycle += lg_delta; if (cycle > sh_delta) { cycle -= sh_delta; x1 += lg_step; } y1 += sh_step; } setSdlPixel(screen, x1, y1, color); } void ProcessSDL::setSdlPixel(SDL_Surface *screen, int x, int y, Uint32 color) { Uint32 *pixmem32; Uint32 colour; //colour = SDL_MapRGB( screen->format, r, g, b ); pixmem32 = (Uint32*) screen->pixels + y + x; *pixmem32 = color; }[/source] My init_SDL looks like this. Perhaps here's the problem: [source lang="cpp"]bool ProcessSDL::initSDL() { //Initialize all SDL subsystems if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 ) { return false; } // atexit(SDL_Quit); // init screen SDL_putenv("SDL_VIDEO_CENTERED=center"); SDL_WM_SetCaption("Ear Tracker", NULL); m_pScreen = SDL_SetVideoMode( 1280,720, 32, SDL_SWSURFACE); if ( m_pScreen == NULL ) { return false; } //init colours c_white = SDL_MapRGB(m_pScreen->format, 255,255,255); c_gray = SDL_MapRGB(m_pScreen->format, 200,200,200); c_dgray= SDL_MapRGB(m_pScreen->format, 64,64,64); c_cyan = SDL_MapRGB(m_pScreen->format, 32,255,255); c_magenta = SDL_MapRGB(m_pScreen->format, 255,0,255); c_yellow = SDL_MapRGB(m_pScreen->format, 255,255,0); c_black = SDL_MapRGB(m_pScreen->format, 0,0,0); c_red = SDL_MapRGB(m_pScreen->format, 255,0,0); c_green = SDL_MapRGB(m_pScreen->format, 0,255,0); c_blue = SDL_MapRGB(m_pScreen->format, 0,0,255); //If everything initialized fine return true; }[/source] Could anyone help me to find out whats wrong? Thank you very much. Greetings.
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