src/video/uikit/SDL_uikitvideo.m

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

#import <UIKit/UIKit.h>

#include "SDL_config.h"

#include "SDL_video.h"
#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_events_c.h"

#include "SDL_uikitvideo.h"
#include "SDL_uikitevents.h"
#include "SDL_uikitwindow.h"
#include "SDL_uikitopengles.h"

#include "SDL_assert.h"

#define UIKITVID_DRIVER_NAME "uikit"

/* Initialization/Query functions */
static int UIKit_VideoInit(_THIS);
static void UIKit_GetDisplayModes(_THIS, SDL_VideoDisplay * sdl_display);
static int UIKit_SetDisplayMode(_THIS, SDL_VideoDisplay * display,
                                SDL_DisplayMode * mode);
static void UIKit_VideoQuit(_THIS);

BOOL SDL_UIKit_supports_multiple_displays = NO;

/* DUMMY driver bootstrap functions */

static int
UIKit_Available(void)
{
    return 1;
}

static void UIKit_DeleteDevice(SDL_VideoDevice * device)
{
    SDL_free(device);
}

static SDL_VideoDevice *
UIKit_CreateDevice(int devindex)
{
    SDL_VideoDevice *device;

    /* Initialize all variables that we clean on shutdown */
    device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
    if (!device) {
        SDL_OutOfMemory();
        if (device) {
            SDL_free(device);
        }
        return (0);
    }

    /* Set the function pointers */
    device->VideoInit = UIKit_VideoInit;
    device->VideoQuit = UIKit_VideoQuit;
    device->GetDisplayModes = UIKit_GetDisplayModes;
    device->SetDisplayMode = UIKit_SetDisplayMode;
    device->PumpEvents = UIKit_PumpEvents;
    device->CreateWindow = UIKit_CreateWindow;
    device->DestroyWindow = UIKit_DestroyWindow;
    device->GetWindowWMInfo = UIKit_GetWindowWMInfo;


    /* OpenGL (ES) functions */
    device->GL_MakeCurrent        = UIKit_GL_MakeCurrent;
    device->GL_SwapWindow        = UIKit_GL_SwapWindow;
    device->GL_CreateContext    = UIKit_GL_CreateContext;
    device->GL_DeleteContext    = UIKit_GL_DeleteContext;
    device->GL_GetProcAddress   = UIKit_GL_GetProcAddress;
    device->GL_LoadLibrary        = UIKit_GL_LoadLibrary;
    device->free = UIKit_DeleteDevice;

    device->gl_config.accelerated = 1;

    return device;
}

VideoBootStrap UIKIT_bootstrap = {
    UIKITVID_DRIVER_NAME, "SDL UIKit video driver",
    UIKit_Available, UIKit_CreateDevice
};


/*
!!! FIXME:

The main screen should list a AxB mode for portrait orientation, and then
 also list BxA for landscape mode. When setting a given resolution, we should
 rotate the view's transform appropriately (extra credit if you check the
 accelerometer and rotate the display so it's never upside down).

  http://iphonedevelopment.blogspot.com/2008/10/starting-in-landscape-mode-without.html

*/

static CGSize
UIKit_ForcePortrait(const CGSize size)
{
    CGSize retval;
    if (size.width < size.height) { // portrait
        retval = size;
    } else {  // landscape
        retval.width = size.height;
        retval.height = size.width;
    }
    return retval;
}

static CGSize
UIKit_ForceLandscape(const CGSize size)
{
    CGSize retval;
    if (size.width > size.height) { // landscape
        retval = size;
    } else {  // portrait
        retval.width = size.height;
        retval.height = size.width;
    }
    return retval;
}

static void
UIKit_GetDisplayModes(_THIS, SDL_VideoDisplay * display)
{
    UIScreen *uiscreen = (UIScreen *) display->driverdata;
    SDL_DisplayMode mode;
    SDL_zero(mode);

    // availableModes showed up in 3.2 (the iPad and later). We should only
    //  land here for at least that version of the OS.
    if (!SDL_UIKit_supports_multiple_displays) {
        const CGRect rect = [uiscreen bounds];
        mode.format = SDL_PIXELFORMAT_ABGR8888;
        mode.w = (int) rect.size.width;
        mode.h = (int) rect.size.height;
        mode.refresh_rate = 0;
        mode.driverdata = NULL;
        SDL_AddDisplayMode(display, &mode);
        mode.w = (int) rect.size.height;  // swap the orientation, add again.
        mode.h = (int) rect.size.width;
        SDL_AddDisplayMode(display, &mode);
        return;
    }

    const int ismain = (uiscreen == [UIScreen mainScreen]);
    const NSArray *modes = [uiscreen availableModes];
    const NSUInteger mode_count = [modes count];
    NSUInteger i;
    for (i = 0; i < mode_count; i++) {
        UIScreenMode *uimode = (UIScreenMode *) [modes objectAtIndex:i];
        CGSize size = [uimode size];
        mode.format = SDL_PIXELFORMAT_ABGR8888;
        mode.refresh_rate = 0;
        mode.driverdata = uimode;
        mode.w = (int) size.width;
        mode.h = (int) size.height;
        if (SDL_AddDisplayMode(display, &mode))
            [uimode retain];

        if (ismain) {
            // Add the mode twice, flipped to portrait and landscape.
            //  SDL_AddDisplayMode() will ignore duplicates.
            size = UIKit_ForcePortrait([uimode size]);
            mode.w = (int) size.width;
            mode.h = (int) size.height;
            if (SDL_AddDisplayMode(display, &mode))
                [uimode retain];

            size = UIKit_ForceLandscape(size);
            mode.w = (int) size.width;
            mode.h = (int) size.height;
            if (SDL_AddDisplayMode(display, &mode))
                [uimode retain];
        }
    }
}


static void
UIKit_AddDisplay(UIScreen *uiscreen, UIScreenMode *uimode, int w, int h)
{
    SDL_VideoDisplay display;
    SDL_DisplayMode mode;
    SDL_zero(mode);
    mode.format = SDL_PIXELFORMAT_ABGR8888;
    mode.w = w;
    mode.h = h;
    mode.refresh_rate = 0;

    [uimode retain];
    mode.driverdata = uimode;

    SDL_zero(display);
    display.desktop_mode = mode;
    display.current_mode = mode;

    [uiscreen retain];
    display.driverdata = uiscreen;
    SDL_AddVideoDisplay(&display);
}


int
UIKit_VideoInit(_THIS)
{
    _this->gl_config.driver_loaded = 1;

    NSString *reqSysVer = @"3.2";
    NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
    if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending)
        SDL_UIKit_supports_multiple_displays = YES;

    // If this is iPhoneOS < 3.2, all devices are one screen, 320x480 pixels.
    //  The iPad added both a larger main screen and the ability to use
    //  external displays.
    if (!SDL_UIKit_supports_multiple_displays) {
        // Just give 'em the whole main screen.
        UIScreen *uiscreen = [UIScreen mainScreen];
        UIScreenMode *uiscreenmode = [uiscreen currentMode];
        const CGRect rect = [uiscreen bounds];
        UIKit_AddDisplay(uiscreen, uiscreenmode, (int)rect.size.width, (int)rect.size.height);
    } else {
        const NSArray *screens = [UIScreen screens];
        const NSUInteger screen_count = [screens count];
        NSUInteger i;
        for (i = 0; i < screen_count; i++) {
            // the main screen is the first element in the array.
            UIScreen *uiscreen = (UIScreen *) [screens objectAtIndex:i];
            UIScreenMode *uiscreenmode = [uiscreen currentMode];
            const CGSize size = [[uiscreen currentMode] size];
            UIKit_AddDisplay(uiscreen, uiscreenmode, (int)size.width, (int)size.height);
        }
    }

    /* We're done! */
    return 0;
}

static int
UIKit_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
{
    UIScreen *uiscreen = (UIScreen *) display->driverdata;
    if (!SDL_UIKit_supports_multiple_displays) {
        // Not on at least iPhoneOS 3.2 (versions prior to iPad).
        SDL_assert(mode->driverdata == NULL);
    } else {
        UIScreenMode *uimode = (UIScreenMode *) mode->driverdata;
        [uiscreen setCurrentMode:uimode];
    }

    return 0;
}

void
UIKit_VideoQuit(_THIS)
{
    // Release Objective-C objects, so higher level doesn't free() them.
    int i, j;
    for (i = 0; i < _this->num_displays; i++) {
        SDL_VideoDisplay *display = &_this->displays[i];
        UIScreen *uiscreen = (UIScreen *) display->driverdata;
        [uiscreen release];
        display->driverdata = NULL;
        for (j = 0; j < display->num_display_modes; j++) {
            SDL_DisplayMode *mode = &display->display_modes[j];
            UIScreenMode *uimode = (UIScreenMode *) mode->driverdata;
            if (uimode) {
                [uimode release];
                mode->driverdata = NULL;
            }
        }
    }
}

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