Mercurial > sdl-ios-xcode
view docs/man3/SDL_ConvertAudio.3 @ 876:9e84d106ec19
(Said Max Horn on the SDL mailing list...)
Hi folks,
based on Eric Wing's patch, I created the attached patch which fixes
the OpenGL coordinate inversion bug in SDL. It works fine over here on
10.3 with Ryan's test program (which I also attached).
There is another change in it: I removed the "- 1" in the two lines
using CGDisplayPixelsHigh()... while I understand from a logical point
of view why they *should* be correct, I checked the actual values
computed that way, and they were off-by-one. After removing the " - 1",
the returned mouse coordinates are correct. I checked this by moving
the mouse to the screen top/bottom in fullscreen mode, BTW. With the
change, the proper values 0 and 479 are returned (in 640x480 mode).
Sam, you may still want to test on 10.1, it's very simple using Ryan's
minimal test code :-)
Cheers,
Max
(Here is the reproduction case for revision history's sake...)
/*
* To compile:
* gcc -o test test.c `sdl-config --cflags` `sdl-config --libs` -framework OpenGL
*
* --ryan.
*/
#include <stdio.h>
#include "SDL.h"
#include "SDL_opengl.h"
int main(int argc, char **argv)
{
Uint32 flags = SDL_OPENGL /* | SDL_FULLSCREEN */;
SDL_Surface *screen;
SDL_Event event;
int done = 0;
GLfloat ratio;
SDL_Init(SDL_INIT_VIDEO);
SDL_ShowCursor(0);
if ((argv[1]) && (strcmp(argv[1], "--grab") == 0))
SDL_WM_GrabInput(SDL_GRAB_ON);
screen = SDL_SetVideoMode(640, 480, 0, flags);
if (!screen)
return(42);
ratio = ((GLfloat) screen->w) / ((GLfloat) screen->h);
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClearDepth( 1.0f );
glEnable( GL_DEPTH_TEST );
glDepthFunc( GL_LEQUAL );
glViewport( 0, 0, screen->w, screen->h);
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 45.0f, ratio, 0.1f, 100.0f );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
SDL_GL_SwapBuffers();
// eh, close enough.
#define MAX_X 6.12
#define MAX_Y 4.50
while (!done)
{
int x, y;
GLfloat glx, gly;
if (!SDL_WaitEvent(&event))
break;
switch (event.type)
{
case SDL_KEYUP:
if (event.key.keysym.sym == SDLK_ESCAPE)
done = 1;
break;
}
SDL_GetMouseState(&x, &y);
glx = ((((GLfloat) x) / ((GLfloat) screen->w)) - 0.5f) * MAX_X;
gly = ((((GLfloat) y) / ((GLfloat) screen->h)) - 0.5f) * MAX_Y;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(glx,-gly,-6.0f);
glBegin(GL_TRIANGLES);
glColor3f(1,0,0); glVertex3f( 0.00f, 0.25f, 0.00f);
glColor3f(0,1,0); glVertex3f(-0.25f, -0.25f, 0.00f);
glColor3f(0,0,1); glVertex3f( 0.25f, -0.25f, 0.00f);
glEnd();
SDL_GL_SwapBuffers();
}
SDL_Quit();
return(0);
}
/* end of test.c ... */
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Mon, 22 Mar 2004 09:38:20 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
line wrap: on
line source
.TH "SDL_ConvertAudio" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" .SH "NAME" SDL_ConvertAudio\- Convert audio data to a desired audio format\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_ConvertAudio\fP\fR(\fBSDL_AudioCVT *cvt\fR); .SH "DESCRIPTION" .PP \fBSDL_ConvertAudio\fP takes one parameter, \fBcvt\fR, which was previously initilized\&. Initilizing a \fI\fBSDL_AudioCVT\fR\fR is a two step process\&. First of all, the structure must be passed to \fI\fBSDL_BuildAudioCVT\fP\fR along with source and destination format parameters\&. Secondly, the \fBcvt\fR->\fBbuf\fR and \fBcvt\fR->\fBlen\fR fields must be setup\&. \fBcvt\fR->\fBbuf\fR should point to the audio data and \fBcvt\fR->\fBlen\fR should be set to the length of the audio data in bytes\&. Remember, the length of the buffer pointed to by \fBbuf\fR show be \fBlen\fR*\fBlen_mult\fR bytes in length\&. .PP Once the \fBSDL_AudioCVT\fRstructure is initilized then we can pass it to \fBSDL_ConvertAudio\fP, which will convert the audio data pointer to by \fBcvt\fR->\fBbuf\fR\&. If \fBSDL_ConvertAudio\fP returned \fB0\fR then the conversion was completed successfully, otherwise \fB-1\fR is returned\&. .PP If the conversion completed successfully then the converted audio data can be read from \fBcvt\fR->\fBbuf\fR\&. The amount of valid, converted, audio data in the buffer is equal to \fBcvt\fR->\fBlen\fR*\fBcvt\fR->\fBlen_ratio\fR\&. .SH "EXAMPLES" .PP .nf \f(CW/* Converting some WAV data to hardware format */ void my_audio_callback(void *userdata, Uint8 *stream, int len); SDL_AudioSpec *desired, *obtained; SDL_AudioSpec wav_spec; SDL_AudioCVT wav_cvt; Uint32 wav_len; Uint8 *wav_buf; int ret; /* Allocated audio specs */ desired=(SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); obtained=(SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); /* Set desired format */ desired->freq=22050; desired->format=AUDIO_S16LSB; desired->samples=8192; desired->callback=my_audio_callback; desired->userdata=NULL; /* Open the audio device */ if ( SDL_OpenAudio(desired, obtained) < 0 ){ fprintf(stderr, "Couldn\&'t open audio: %s ", SDL_GetError()); exit(-1); } free(desired); /* Load the test\&.wav */ if( SDL_LoadWAV("test\&.wav", &wav_spec, &wav_buf, &wav_len) == NULL ){ fprintf(stderr, "Could not open test\&.wav: %s ", SDL_GetError()); SDL_CloseAudio(); free(obtained); exit(-1); } /* Build AudioCVT */ ret = SDL_BuildAudioCVT(&wav_cvt, wav_spec\&.format, wav_spec\&.channels, wav_spec\&.freq, obtained->format, obtained->channels, obtained->freq); /* Check that the convert was built */ if(ret==-1){ fprintf(stderr, "Couldn\&'t build converter! "); SDL_CloseAudio(); free(obtained); SDL_FreeWAV(wav_buf); } /* Setup for conversion */ wav_cvt\&.buf=(Uint8 *)malloc(wav_len*wav_cvt\&.len_mult); wav_cvt\&.len=wav_len; memcpy(wav_cvt\&.buf, wav_buf, wav_len); /* We can delete to original WAV data now */ SDL_FreeWAV(wav_buf); /* And now we\&'re ready to convert */ SDL_ConvertAudio(&wav_cvt); /* do whatever */ \&. \&. \&. \&. \fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_BuildAudioCVT\fP\fR, \fI\fBSDL_AudioCVT\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58