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Fixed bug #55 From Christian Walther: When writing my patch for #12, I ended up doing all sorts of changes to the way application/window activating/deactivating is handled in the Quartz backend, resulting in the attached patch. It does make the code a bit cleaner IMHO, but as it might be regarded as a case of "if it ain't broken, don't fix it" I'd like to hear other people's opinion about it. Please shout if some change strikes you as unnecessary or wrong, and I'll explain the reasons behind it. As far as I tested it, it does not introduce any new bugs, but I may well have missed some. - The most fundamental change (that triggered most of the others) is irrelevant for the usual single-window SDL applications, it only affects the people who are crazy enough to display other Cocoa windows alongside the SDL window (I'm actually doing this currently, although the additional window only displays debugging info and won't be present in the final product): Before, some things were done on the application becoming active, some on the window becoming key, and some on the window becoming main. Conceptually, all these actions belong to the window becoming key, so that's what I implemented. However, since in a single-window application these three events always happen together, the previous implementation "ain't broken". - This slightly changed the meaning of the SDL_APPMOUSEFOCUS flag from SDL_GetAppState(): Before, it meant "window is main and mouse is inside window (or mode is fullscreen)". Now, it means "window is key and mouse is inside window (or mode is fullscreen)". It makes more sense to me that way. (See http://developer.apple.com/documentation/Cocoa/Conceptual/WinPanel/Concepts/ChangingMainKeyWindow.html for a discussion of what key and main windows are.) The other two flags are unchanged: SDL_APPACTIVE = application is not hidden and window is not minimized, SDL_APPINPUTFOCUS = window is key (or mode is fullscreen). - As a side effect, the reorganization fixes the following two issues (and maybe others) (but they could also be fixed in less invasive ways): * A regression that was introduced in revision 1.42 of SDL_QuartzVideo.m (http://libsdl.org/cgi/cvsweb.cgi/SDL12/src/video/quartz/SDL_QuartzVideo.m.diff?r1=1.41&r2=1.42) (from half-desirable to undesirable behavior): Situation: While in windowed mode, hide the cursor using SDL_ShowCursor(SDL_DISABLE), move the mouse outside of the window so that the cursor becomes visible again, and SDL_SetVideoMode() to a fullscreen mode. What happened before revision 1.42: The cursor is visible, but becomes invisible as soon as the mouse is moved (half-desirable). What happens in revision 1.42 and after (including current CVS): The cursor is visible and stays visible (undesirable). What happens after my patch: The cursor is invisible from the beginning (desirable). * When the cursor is hidden and grabbed, switch away from the application using cmd-tab (which ungrabs and makes the cursor visible), move the cursor outside of the SDL window, then cmd-tab back to the application. In 1.2.8 and in the current CVS, the cursor is re-grabbed, but it stays visible (immovable in the middle of the window). With my patch, the cursor is correctly re-grabbed and hidden. (For some reason, it still doesn't work correctly if you switch back to the application using the dock instead of cmd-tab. I haven't been able to figure out why. I can step over [NSCursor hide] being called in the debugger, but it seems to have no effect.) - The patch includes my patch for #12 (it was easier to obtain using cvs diff that way). If you apply both of them, you will end up with 6 duplicate lines in SDL_QuartzEvents.m.
author Sam Lantinga <slouken@libsdl.org>
date Thu, 13 Apr 2006 14:17:48 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Graphics and Video</TITLE
><META
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"><LINK
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>SDL Library Documentation</TH
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><DIV
CLASS="CHAPTER"
><H1
><A
NAME="GUIDEVIDEO"
></A
>Chapter 2. Graphics and Video</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="GUIDEVIDEOINTRO"
></A
>Introduction to SDL Video</H1
><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="AEN68"
></A
>Initializing the Video Display</H2
><P
>This is what almost all SDL programs have to do in one way or
another.</P
><DIV
CLASS="EXAMPLE"
><A
NAME="AEN71"
></A
><P
><B
>Example 2-1. Initializing the Video Display</B
></P
><PRE
CLASS="PROGRAMLISTING"
>    SDL_Surface *screen;

    /* Initialize the SDL library */
    if( SDL_Init(SDL_INIT_VIDEO) &#60; 0 ) {
        fprintf(stderr,
                "Couldn't initialize SDL: %s\n", SDL_GetError());
        exit(1);
    }

    /* Clean up on exit */
    atexit(SDL_Quit);
    
    /*
     * Initialize the display in a 640x480 8-bit palettized mode,
     * requesting a software surface
     */
    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"
></A
>Initializing the Best Video Mode</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-&#62;format-&#62;BitsPerPixel);</PRE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN80"
></A
>Loading and Displaying a BMP File</H2
><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="AEN83"
></A
><P
><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-&#62;format-&#62;palette &#38;&#38; screen-&#62;format-&#62;palette) {
    SDL_SetColors(screen, image-&#62;format-&#62;palette-&#62;colors, 0,
                  image-&#62;format-&#62;palette-&#62;ncolors);
    }

    /* Blit onto the screen surface */
    if(SDL_BlitSurface(image, NULL, screen, NULL) &#60; 0)
        fprintf(stderr, "BlitSurface error: %s\n", SDL_GetError());

    SDL_UpdateRect(screen, 0, 0, image-&#62;w, image-&#62;h);

    /* Free the allocated BMP surface */
    SDL_FreeSurface(image);
}</PRE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN86"
></A
>Drawing Directly to the Display</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"
>/*
 * Return the pixel value at (x, y)
 * NOTE: The surface must be locked before calling this!
 */
Uint32 getpixel(SDL_Surface *surface, int x, int y)
{
    int bpp = surface-&#62;format-&#62;BytesPerPixel;
    /* Here p is the address to the pixel we want to retrieve */
    Uint8 *p = (Uint8 *)surface-&#62;pixels + y * surface-&#62;pitch + x * bpp;

    switch(bpp) {
    case 1:
        return *p;

    case 2:
        return *(Uint16 *)p;

    case 3:
        if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
            return p[0] &#60;&#60; 16 | p[1] &#60;&#60; 8 | p[2];
        else
            return p[0] | p[1] &#60;&#60; 8 | p[2] &#60;&#60; 16;

    case 4:
        return *(Uint32 *)p;

    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-&#62;format-&#62;BytesPerPixel;
    /* Here p is the address to the pixel we want to set */
    Uint8 *p = (Uint8 *)surface-&#62;pixels + y * surface-&#62;pitch + x * bpp;

    switch(bpp) {
    case 1:
        *p = pixel;
        break;

    case 2:
        *(Uint16 *)p = pixel;
        break;

    case 3:
        if(SDL_BYTEORDER == SDL_BIG_ENDIAN) {
            p[0] = (pixel &#62;&#62; 16) &#38; 0xff;
            p[1] = (pixel &#62;&#62; 8) &#38; 0xff;
            p[2] = pixel &#38; 0xff;
        } else {
            p[0] = pixel &#38; 0xff;
            p[1] = (pixel &#62;&#62; 8) &#38; 0xff;
            p[2] = (pixel &#62;&#62; 16) &#38; 0xff;
        }
        break;

    case 4:
        *(Uint32 *)p = pixel;
        break;
    }
}</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"
>&#13;    /* Code to set a yellow pixel at the center of the screen */

    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-&#62;format, 0xff, 0xff, 0x00);

    x = screen-&#62;w / 2;
    y = screen-&#62;h / 2;

    /* Lock the screen for direct access to the pixels */
    if ( SDL_MUSTLOCK(screen) ) {
        if ( SDL_LockSurface(screen) &#60; 0 ) {
            fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError());
            return;
        }
    }

    putpixel(screen, x, y, yellow);

    if ( SDL_MUSTLOCK(screen) ) {
        SDL_UnlockSurface(screen);
    }
    /* Update just the part of the display that we've changed */
    SDL_UpdateRect(screen, x, y, 1, 1);

    return;&#13;</PRE
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