Mercurial > sdl-ios-xcode
diff docs/html/guidevideo.html @ 55:55f1f1b3e27d
Added new docs for SDL 1.2.1
| author | Sam Lantinga <slouken@lokigames.com> |
|---|---|
| date | Sun, 10 Jun 2001 19:31:57 +0000 |
| parents | 74212992fb08 |
| children | 355632dca928 |
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--- a/docs/html/guidevideo.html Sun Jun 10 18:39:47 2001 +0000 +++ b/docs/html/guidevideo.html Sun Jun 10 19:31:57 2001 +0000 @@ -4,7 +4,7 @@ >Graphics and Video</TITLE ><META NAME="GENERATOR" -CONTENT="Modular DocBook HTML Stylesheet Version 1.61 +CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" @@ -16,8 +16,8 @@ TITLE="Initializing SDL" HREF="guidebasicsinit.html"><LINK REL="NEXT" -TITLE="Input handling" -HREF="guideinput.html"></HEAD +TITLE="Using OpenGL With SDL" +HREF="guidevideoopengl.html"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFF8DC" @@ -57,7 +57,7 @@ ALIGN="right" VALIGN="bottom" ><A -HREF="guideinput.html" +HREF="guidevideoopengl.html" >Next</A ></TD ></TR @@ -73,572 +73,322 @@ >Chapter 2. Graphics and Video</A ></H1 ><DIV +CLASS="TOC" +><DL +><DT +><B +>Table of Contents</B +></DT +><DT +><A +HREF="guidevideo.html#GUIDEVIDEOINTRO" +>Introduction to SDL Video</A +></DT +><DT +><A +HREF="guidevideoopengl.html" +>Using OpenGL With SDL</A +></DT +></DL +></DIV +><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A -NAME="GUIDEVIDEOOPENGL" ->Using OpenGL With SDL</A +NAME="GUIDEVIDEOINTRO" +>Introduction to SDL Video</A ></H1 ><P ->SDL has the ability to create and use OpenGL contexts on several platforms(Linux/X11, Win32, BeOS, MacOS Classic/Toolbox, MacOS X, FreeBSD/X11 and Solaris/X11). This allows you to use SDL's audio, event handling, threads and times in your OpenGL applications (a function often performed by GLUT).</P +>Video is probably the most common thing that SDL is used for, and +so it has the most complete subsystem. Here are a few +examples to demonstrate the basics.</P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A -NAME="AEN65" ->Initialisation</A +NAME="AEN68" +>Initializing the Video Display</A ></H2 ><P ->Initialising SDL to use OpenGL is not very different to initialising SDL normally. There are three differences; you must pass <TT -CLASS="LITERAL" ->SDL_OPENGL</TT -> to <A -HREF="sdlsetvideomode.html" -><TT -CLASS="FUNCTION" ->SDL_SetVideoMode</TT +>This is what almost all SDL programs have to do in one way or +another.</P +><DIV +CLASS="EXAMPLE" +><A +NAME="AEN71" ></A ->, you must specify several GL attributes (depth buffer size, framebuffer sizes) using <A -HREF="sdlglsetattribute.html" -><TT -CLASS="FUNCTION" ->SDL_GL_SetAttribute</TT -></A -> and finally, if you wish to use double buffering you must specify it as a GL attribute, <I -CLASS="EMPHASIS" ->not</I -> by passing the <TT -CLASS="LITERAL" ->SDL_DOUBLEBUF</TT -> flag to <TT -CLASS="FUNCTION" ->SDL_SetVideoMode</TT ->. -<PRE +><P +><B +>Example 2-1. Initializing the Video Display</B +></P +><PRE CLASS="PROGRAMLISTING" -> /* Information about the current video settings. */ - const SDL_VideoInfo* info = NULL; - /* Dimensions of our window. */ - int width = 0; - int height = 0; - /* Color depth in bits of our window. */ - int bpp = 0; - /* Flags we will pass into SDL_SetVideoMode. */ - int flags = 0; +> SDL_Surface *screen; - /* First, initialize SDL's video subsystem. */ - if( SDL_Init( SDL_INIT_VIDEO ) < 0 ) { - /* Failed, exit. */ - fprintf( stderr, "Video initialization failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); - } - - /* Let's get some video information. */ - info = SDL_GetVideoInfo( ); - - if( !info ) { - /* This should probably never happen. */ - fprintf( stderr, "Video query failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); + /* Initialize the SDL library */ + if( SDL_Init(SDL_INIT_VIDEO) < 0 ) { + fprintf(stderr, + "Couldn't initialize SDL: %s\n", SDL_GetError()); + exit(1); } - /* - * Set our width/height to 640/480 (you would - * of course let the user decide this in a normal - * app). We get the bpp we will request from - * the display. On X11, VidMode can't change - * resolution, so this is probably being overly - * safe. Under Win32, ChangeDisplaySettings - * can change the bpp. - */ - width = 640; - height = 480; - bpp = info->vfmt->BitsPerPixel; - + /* Clean up on exit */ + atexit(SDL_Quit); + /* - * Now, we want to setup our requested - * window attributes for our OpenGL window. - * We want *at least* 5 bits of red, green - * and blue. We also want at least a 16-bit - * depth buffer. - * - * The last thing we do is request a double - * buffered window. '1' turns on double - * buffering, '0' turns it off. - * - * Note that we do not use SDL_DOUBLEBUF in - * the flags to SDL_SetVideoMode. That does - * not affect the GL attribute state, only - * the standard 2D blitting setup. + * Initialize the display in a 640x480 8-bit palettized mode, + * requesting a software surface */ - SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 ); - SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); - - /* - * We want to request that SDL provide us - * with an OpenGL window, in a fullscreen - * video mode. - * - * EXERCISE: - * Make starting windowed an option, and - * handle the resize events properly with - * glViewport. - */ - flags = SDL_OPENGL | SDL_FULLSCREEN; - - /* - * Set the video mode - */ - if( SDL_SetVideoMode( width, height, bpp, flags ) == 0 ) { - /* - * This could happen for a variety of reasons, - * including DISPLAY not being set, the specified - * resolution not being available, etc. - */ - fprintf( stderr, "Video mode set failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); + screen = SDL_SetVideoMode(640, 480, 8, SDL_SWSURFACE); + if ( screen == NULL ) { + fprintf(stderr, "Couldn't set 640x480x8 video mode: %s\n", + SDL_GetError()); + exit(1); }</PRE +></DIV +></DIV +><DIV +CLASS="SECT2" +><H2 +CLASS="SECT2" +><A +NAME="AEN74" +>Initializing the Best Video Mode</A +></H2 +><P +>If you have a preference for a certain pixel depth but will accept any +other, use SDL_SetVideoMode with SDL_ANYFORMAT as below. You can also +use SDL_VideoModeOK() to find the native video mode that is closest to +the mode you request.</P +><DIV +CLASS="EXAMPLE" +><A +NAME="AEN77" +></A +><P +><B +>Example 2-2. Initializing the Best Video Mode</B ></P +><PRE +CLASS="PROGRAMLISTING" +> /* Have a preference for 8-bit, but accept any depth */ + screen = SDL_SetVideoMode(640, 480, 8, SDL_SWSURFACE|SDL_ANYFORMAT); + if ( screen == NULL ) { + fprintf(stderr, "Couldn't set 640x480x8 video mode: %s\n", + SDL_GetError()); + exit(1); + } + printf("Set 640x480 at %d bits-per-pixel mode\n", + screen->format->BitsPerPixel);</PRE +></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A -NAME="AEN77" ->Drawing</A +NAME="AEN80" +>Loading and Displaying a BMP File</A ></H2 ><P ->Apart from initialisation, using OpenGL within SDL is the same as using. However if you have request a double buffered display (using <A -HREF="sdlglsetattribute.html" -><TT -CLASS="FUNCTION" ->SDL_GL_SetAttribute</TT -></A ->) and one (which can be checked by using <A -HREF="sdlglgetattribute.html" -><TT -CLASS="FUNCTION" ->SDL_GL_GetAttribute</TT -></A ->), then you must use <A -HREF="sdlglswapbuffers.html" -><TT -CLASS="FUNCTION" ->SDL_GL_SwapBuffers()</TT -></A -> to swap the buffers and update the display.</P -><P ->A full example code listing is now presented below.</P +>The following function loads and displays a BMP file given as +argument, once SDL is initialised and a video mode has been set.</P ><DIV CLASS="EXAMPLE" ><A -NAME="AEN87" +NAME="AEN83" ></A ><P ><B ->Example 2-1. gl.c - SDL OpenGL Example</B +>Example 2-3. Loading and Displaying a BMP File</B +></P +><PRE +CLASS="PROGRAMLISTING" +>void display_bmp(char *file_name) +{ + SDL_Surface *image; + + /* Load the BMP file into a surface */ + image = SDL_LoadBMP(file_name); + if (image == NULL) { + fprintf(stderr, "Couldn't load %s: %s\n", file_name, SDL_GetError()); + return; + } + + /* + * Palettized screen modes will have a default palette (a standard + * 8*8*4 colour cube), but if the image is palettized as well we can + * use that palette for a nicer colour matching + */ + if (image->format->palette && screen->format->palette) { + SDL_SetColors(screen, image->format->palette->colors, 0, + image->format->palette->ncolors); + } + + /* Blit onto the screen surface */ + if(SDL_BlitSurface(image, NULL, screen, NULL) < 0) + fprintf(stderr, "BlitSurface error: %s\n", SDL_GetError()); + + SDL_UpdateRect(screen, 0, 0, image->w, image->h); + + /* Free the allocated BMP surface */ + SDL_FreeSurface(image); +}</PRE +></DIV +></DIV +><DIV +CLASS="SECT2" +><H2 +CLASS="SECT2" +><A +NAME="AEN86" +>Drawing Directly to the Display</A +></H2 +><P +>The following two functions can be used to get and set single +pixels of a surface. They are carefully written to work with any depth +currently supported by SDL. Remember to lock the surface before +calling them, and to unlock it before calling any other SDL +functions.</P +><P +>To convert between pixel values and their red, green, blue +components, use SDL_GetRGB() and SDL_MapRGB().</P +><DIV +CLASS="EXAMPLE" +><A +NAME="AEN90" +></A +><P +><B +>Example 2-4. getpixel()</B ></P ><PRE CLASS="PROGRAMLISTING" >/* - * SDL OpenGL Tutorial. - * (c) Michael Vance, 2000 - * briareos@lokigames.com - * - * Distributed under terms of the LGPL. + * Return the pixel value at (x, y) + * NOTE: The surface must be locked before calling this! */ - -#include <SDL/SDL.h> -#include <GL/gl.h> -#include <GL/glu.h> - -#include <stdio.h> -#include <stdlib.h> - -static GLboolean should_rotate = GL_TRUE; - -static void quit_tutorial( int code ) +Uint32 getpixel(SDL_Surface *surface, int x, int y) { - /* - * Quit SDL so we can release the fullscreen - * mode and restore the previous video settings, - * etc. - */ - SDL_Quit( ); + int bpp = surface->format->BytesPerPixel; + /* Here p is the address to the pixel we want to retrieve */ + Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp; + + switch(bpp) { + case 1: + return *p; - /* Exit program. */ - exit( code ); -} + case 2: + return *(Uint16 *)p; -static void handle_key_down( SDL_keysym* keysym ) -{ + case 3: + if(SDL_BYTEORDER == SDL_BIG_ENDIAN) + return p[0] << 16 | p[1] << 8 | p[2]; + else + return p[0] | p[1] << 8 | p[2] << 16; + + case 4: + return *(Uint32 *)p; - /* - * We're only interested if 'Esc' has - * been presssed. - * - * EXERCISE: - * Handle the arrow keys and have that change the - * viewing position/angle. - */ - switch( keysym->sym ) { - case SDLK_ESCAPE: - quit_tutorial( 0 ); + default: + return 0; /* shouldn't happen, but avoids warnings */ + } +}</PRE +></DIV +><DIV +CLASS="EXAMPLE" +><A +NAME="AEN93" +></A +><P +><B +>Example 2-5. putpixel()</B +></P +><PRE +CLASS="PROGRAMLISTING" +>/* + * Set the pixel at (x, y) to the given value + * NOTE: The surface must be locked before calling this! + */ +void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel) +{ + int bpp = surface->format->BytesPerPixel; + /* Here p is the address to the pixel we want to set */ + Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp; + + switch(bpp) { + case 1: + *p = pixel; break; - case SDLK_SPACE: - should_rotate = !should_rotate; + + case 2: + *(Uint16 *)p = pixel; break; - default: + + case 3: + if(SDL_BYTEORDER == SDL_BIG_ENDIAN) { + p[0] = (pixel >> 16) & 0xff; + p[1] = (pixel >> 8) & 0xff; + p[2] = pixel & 0xff; + } else { + p[0] = pixel & 0xff; + p[1] = (pixel >> 8) & 0xff; + p[2] = (pixel >> 16) & 0xff; + } + break; + + case 4: + *(Uint32 *)p = pixel; break; } - -} - -static void process_events( void ) -{ - /* Our SDL event placeholder. */ - SDL_Event event; - - /* Grab all the events off the queue. */ - while( SDL_PollEvent( &event ) ) { - - switch( event.type ) { - case SDL_KEYDOWN: - /* Handle key presses. */ - handle_key_down( &event.key.keysym ); - break; - case SDL_QUIT: - /* Handle quit requests (like Ctrl-c). */ - quit_tutorial( 0 ); - break; - } - - } - -} - -static void draw_screen( void ) -{ - /* Our angle of rotation. */ - static float angle = 0.0f; +}</PRE +></DIV +><P +>The following code uses the putpixel() function above to set a +yellow pixel in the middle of the screen.</P +><DIV +CLASS="EXAMPLE" +><A +NAME="AEN97" +></A +><P +><B +>Example 2-6. Using putpixel()</B +></P +><PRE +CLASS="PROGRAMLISTING" +> /* Code to set a yellow pixel at the center of the screen */ - /* - * EXERCISE: - * Replace this awful mess with vertex - * arrays and a call to glDrawElements. - * - * EXERCISE: - * After completing the above, change - * it to use compiled vertex arrays. - * - * EXERCISE: - * Verify my windings are correct here ;). - */ - static GLfloat v0[] = { -1.0f, -1.0f, 1.0f }; - static GLfloat v1[] = { 1.0f, -1.0f, 1.0f }; - static GLfloat v2[] = { 1.0f, 1.0f, 1.0f }; - static GLfloat v3[] = { -1.0f, 1.0f, 1.0f }; - static GLfloat v4[] = { -1.0f, -1.0f, -1.0f }; - static GLfloat v5[] = { 1.0f, -1.0f, -1.0f }; - static GLfloat v6[] = { 1.0f, 1.0f, -1.0f }; - static GLfloat v7[] = { -1.0f, 1.0f, -1.0f }; - static GLubyte red[] = { 255, 0, 0, 255 }; - static GLubyte green[] = { 0, 255, 0, 255 }; - static GLubyte blue[] = { 0, 0, 255, 255 }; - static GLubyte white[] = { 255, 255, 255, 255 }; - static GLubyte yellow[] = { 0, 255, 255, 255 }; - static GLubyte black[] = { 0, 0, 0, 255 }; - static GLubyte orange[] = { 255, 255, 0, 255 }; - static GLubyte purple[] = { 255, 0, 255, 0 }; + int x, y; + Uint32 yellow; + + /* Map the color yellow to this display (R=0xff, G=0xFF, B=0x00) + Note: If the display is palettized, you must set the palette first. + */ + yellow = SDL_MapRGB(screen->format, 0xff, 0xff, 0x00); - /* Clear the color and depth buffers. */ - glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); - - /* We don't want to modify the projection matrix. */ - glMatrixMode( GL_MODELVIEW ); - glLoadIdentity( ); - - /* Move down the z-axis. */ - glTranslatef( 0.0, 0.0, -5.0 ); + x = screen->w / 2; + y = screen->h / 2; - /* Rotate. */ - glRotatef( angle, 0.0, 1.0, 0.0 ); - - if( should_rotate ) { - - if( ++angle > 360.0f ) { - angle = 0.0f; + /* Lock the screen for direct access to the pixels */ + if ( SDL_MUSTLOCK(screen) ) { + if ( SDL_LockSurface(screen) < 0 ) { + fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError()); + return; } - } - /* Send our triangle data to the pipeline. */ - glBegin( GL_TRIANGLES ); - - glColor4ubv( red ); - glVertex3fv( v0 ); - glColor4ubv( green ); - glVertex3fv( v1 ); - glColor4ubv( blue ); - glVertex3fv( v2 ); - - glColor4ubv( red ); - glVertex3fv( v0 ); - glColor4ubv( blue ); - glVertex3fv( v2 ); - glColor4ubv( white ); - glVertex3fv( v3 ); - - glColor4ubv( green ); - glVertex3fv( v1 ); - glColor4ubv( black ); - glVertex3fv( v5 ); - glColor4ubv( orange ); - glVertex3fv( v6 ); - - glColor4ubv( green ); - glVertex3fv( v1 ); - glColor4ubv( orange ); - glVertex3fv( v6 ); - glColor4ubv( blue ); - glVertex3fv( v2 ); - - glColor4ubv( black ); - glVertex3fv( v5 ); - glColor4ubv( yellow ); - glVertex3fv( v4 ); - glColor4ubv( purple ); - glVertex3fv( v7 ); - - glColor4ubv( black ); - glVertex3fv( v5 ); - glColor4ubv( purple ); - glVertex3fv( v7 ); - glColor4ubv( orange ); - glVertex3fv( v6 ); - - glColor4ubv( yellow ); - glVertex3fv( v4 ); - glColor4ubv( red ); - glVertex3fv( v0 ); - glColor4ubv( white ); - glVertex3fv( v3 ); - - glColor4ubv( yellow ); - glVertex3fv( v4 ); - glColor4ubv( white ); - glVertex3fv( v3 ); - glColor4ubv( purple ); - glVertex3fv( v7 ); - - glColor4ubv( white ); - glVertex3fv( v3 ); - glColor4ubv( blue ); - glVertex3fv( v2 ); - glColor4ubv( orange ); - glVertex3fv( v6 ); - - glColor4ubv( white ); - glVertex3fv( v3 ); - glColor4ubv( orange ); - glVertex3fv( v6 ); - glColor4ubv( purple ); - glVertex3fv( v7 ); - - glColor4ubv( green ); - glVertex3fv( v1 ); - glColor4ubv( red ); - glVertex3fv( v0 ); - glColor4ubv( yellow ); - glVertex3fv( v4 ); - - glColor4ubv( green ); - glVertex3fv( v1 ); - glColor4ubv( yellow ); - glVertex3fv( v4 ); - glColor4ubv( black ); - glVertex3fv( v5 ); - - glEnd( ); - - /* - * EXERCISE: - * Draw text telling the user that 'Spc' - * pauses the rotation and 'Esc' quits. - * Do it using vetors and textured quads. - */ - - /* - * Swap the buffers. This this tells the driver to - * render the next frame from the contents of the - * back-buffer, and to set all rendering operations - * to occur on what was the front-buffer. - * - * Double buffering prevents nasty visual tearing - * from the application drawing on areas of the - * screen that are being updated at the same time. - */ - SDL_GL_SwapBuffers( ); -} - -static void setup_opengl( int width, int height ) -{ - float ratio = (float) width / (float) height; - - /* Our shading model--Gouraud (smooth). */ - glShadeModel( GL_SMOOTH ); - - /* Culling. */ - glCullFace( GL_BACK ); - glFrontFace( GL_CCW ); - glEnable( GL_CULL_FACE ); - - /* Set the clear color. */ - glClearColor( 0, 0, 0, 0 ); - - /* Setup our viewport. */ - glViewport( 0, 0, width, height ); + putpixel(screen, x, y, yellow); - /* - * Change to the projection matrix and set - * our viewing volume. - */ - glMatrixMode( GL_PROJECTION ); - glLoadIdentity( ); - /* - * EXERCISE: - * Replace this with a call to glFrustum. - */ - gluPerspective( 60.0, ratio, 1.0, 1024.0 ); -} - -int main( int argc, char* argv[] ) -{ - /* Information about the current video settings. */ - const SDL_VideoInfo* info = NULL; - /* Dimensions of our window. */ - int width = 0; - int height = 0; - /* Color depth in bits of our window. */ - int bpp = 0; - /* Flags we will pass into SDL_SetVideoMode. */ - int flags = 0; - - /* First, initialize SDL's video subsystem. */ - if( SDL_Init( SDL_INIT_VIDEO ) < 0 ) { - /* Failed, exit. */ - fprintf( stderr, "Video initialization failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); + if ( SDL_MUSTLOCK(screen) ) { + SDL_UnlockSurface(screen); } - - /* Let's get some video information. */ - info = SDL_GetVideoInfo( ); - - if( !info ) { - /* This should probably never happen. */ - fprintf( stderr, "Video query failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); - } - - /* - * Set our width/height to 640/480 (you would - * of course let the user decide this in a normal - * app). We get the bpp we will request from - * the display. On X11, VidMode can't change - * resolution, so this is probably being overly - * safe. Under Win32, ChangeDisplaySettings - * can change the bpp. - */ - width = 640; - height = 480; - bpp = info->vfmt->BitsPerPixel; + /* Update just the part of the display that we've changed */ + SDL_UpdateRect(screen, x, y, 1, 1); - /* - * Now, we want to setup our requested - * window attributes for our OpenGL window. - * We want *at least* 5 bits of red, green - * and blue. We also want at least a 16-bit - * depth buffer. - * - * The last thing we do is request a double - * buffered window. '1' turns on double - * buffering, '0' turns it off. - * - * Note that we do not use SDL_DOUBLEBUF in - * the flags to SDL_SetVideoMode. That does - * not affect the GL attribute state, only - * the standard 2D blitting setup. - */ - SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 ); - SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 ); - SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); - - /* - * We want to request that SDL provide us - * with an OpenGL window, in a fullscreen - * video mode. - * - * EXERCISE: - * Make starting windowed an option, and - * handle the resize events properly with - * glViewport. - */ - flags = SDL_OPENGL | SDL_FULLSCREEN; - - /* - * Set the video mode - */ - if( SDL_SetVideoMode( width, height, bpp, flags ) == 0 ) { - /* - * This could happen for a variety of reasons, - * including DISPLAY not being set, the specified - * resolution not being available, etc. - */ - fprintf( stderr, "Video mode set failed: %s\n", - SDL_GetError( ) ); - quit_tutorial( 1 ); - } - - /* - * At this point, we should have a properly setup - * double-buffered window for use with OpenGL. - */ - setup_opengl( width, height ); - - /* - * Now we want to begin our normal app process-- - * an event loop with a lot of redrawing. - */ - while( 1 ) { - /* Process incoming events. */ - process_events( ); - /* Draw the screen. */ - draw_screen( ); - } - - /* - * EXERCISE: - * Record timings using SDL_GetTicks() and - * and print out frames per second at program - * end. - */ - - /* Never reached. */ - return 0; -}</PRE + return; </PRE ></DIV ></DIV ></DIV @@ -674,7 +424,7 @@ ALIGN="right" VALIGN="top" ><A -HREF="guideinput.html" +HREF="guidevideoopengl.html" >Next</A ></TD ></TR @@ -696,7 +446,7 @@ WIDTH="33%" ALIGN="right" VALIGN="top" ->Input handling</TD +>Using OpenGL With SDL</TD ></TR ></TABLE ></DIV