Mercurial > sdl-ios-xcode
view docs/html/audio.html @ 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 | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >Audio</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="SDL Reference" HREF="reference.html"><LINK REL="PREVIOUS" TITLE="SDL_JoystickClose" HREF="sdljoystickclose.html"><LINK REL="NEXT" TITLE="SDL_AudioSpec" HREF="sdlaudiospec.html"><META NAME="KEYWORD" CONTENT="audio"><META NAME="KEYWORD" CONTENT="function"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdljoystickclose.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlaudiospec.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="AUDIO" ></A >Chapter 10. Audio</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="sdlaudiospec.html" >SDL_AudioSpec</A > -- Audio Specification Structure</DT ><DT ><A HREF="sdlopenaudio.html" >SDL_OpenAudio</A > -- Opens the audio device with the desired parameters.</DT ><DT ><A HREF="sdlpauseaudio.html" >SDL_PauseAudio</A > -- Pauses and unpauses the audio callback processing</DT ><DT ><A HREF="sdlgetaudiostatus.html" >SDL_GetAudioStatus</A > -- Get the current audio state</DT ><DT ><A HREF="sdlloadwav.html" >SDL_LoadWAV</A > -- Load a WAVE file</DT ><DT ><A HREF="sdlfreewav.html" >SDL_FreeWAV</A > -- Frees previously opened WAV data</DT ><DT ><A HREF="sdlaudiocvt.html" >SDL_AudioCVT</A > -- Audio Conversion Structure</DT ><DT ><A HREF="sdlbuildaudiocvt.html" >SDL_BuildAudioCVT</A > -- Initializes a SDL_AudioCVT structure for conversion</DT ><DT ><A HREF="sdlconvertaudio.html" >SDL_ConvertAudio</A > -- Convert audio data to a desired audio format.</DT ><DT ><A HREF="sdlmixaudio.html" >SDL_MixAudio</A > -- Mix audio data</DT ><DT ><A HREF="sdllockaudio.html" >SDL_LockAudio</A > -- Lock out the callback function</DT ><DT ><A HREF="sdlunlockaudio.html" >SDL_UnlockAudio</A > -- Unlock the callback function</DT ><DT ><A HREF="sdlcloseaudio.html" >SDL_CloseAudio</A > -- Shuts down audio processing and closes the audio device.</DT ></DL ></DIV ><P >Sound on the computer is translated from waves that you hear into a series of values, or samples, each representing the amplitude of the wave. When these samples are sent in a stream to a sound card, an approximation of the original wave can be recreated. The more bits used to represent the amplitude, and the greater frequency these samples are gathered, the closer the approximated sound is to the original, and the better the quality of sound.</P ><P >This library supports both 8 and 16 bit signed and unsigned sound samples, at frequencies ranging from 11025 Hz to 44100 Hz, depending on the underlying hardware. If the hardware doesn't support the desired audio format or frequency, it can be emulated if desired (See <A HREF="sdlopenaudio.html" ><TT CLASS="FUNCTION" >SDL_OpenAudio()</TT ></A >)</P ><P >A commonly supported audio format is 16 bits per sample at 22050 Hz.</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdljoystickclose.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlaudiospec.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_JoystickClose</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_AudioSpec</TD ></TR ></TABLE ></DIV ></BODY ></HTML >