magnum/src/Platform/Sdl2Application.cpp

/*
    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>

    This file is part of Magnum.

    Magnum is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License version 3
    only, as published by the Free Software Foundation.

    Magnum is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Lesser General Public License version 3 for more details.
*/

#include "Sdl2Application.h"

#include "Context.h"
#include "ExtensionWrangler.h"

namespace Magnum { namespace Platform {

Sdl2Application::Sdl2Application(int, char**, const std::string& name, const Math::Vector2<GLsizei>& size): _redraw(true) {
    if(SDL_Init(SDL_INIT_VIDEO) < 0) {
        Error() << "Cannot initialize SDL.";
        exit(1);
    }

    /* Request OpenGL 3.2 */
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);

    /* Enable double buffering and 24bt depth buffer */
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);

    window = SDL_CreateWindow(name.c_str(), SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
        size.x(), size.y(), SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN);
    if(!window) {
        Error() << "Cannot create window.";
        exit(2);
    }

    context = SDL_GL_CreateContext(window);

    /* This must be enabled, otherwise (on my NVidia) it crashes when creating
       VAO. WTF. */
    ExtensionWrangler::initialize(ExtensionWrangler::ExperimentalFeatures::Enable);

    /* Push resize event, so viewportEvent() is called at startup */
    SDL_Event* sizeEvent = new SDL_Event;
    sizeEvent->type = SDL_WINDOWEVENT;
    sizeEvent->window.event = SDL_WINDOWEVENT_RESIZED;
    sizeEvent->window.data1 = size.x();
    sizeEvent->window.data2 = size.y();
    SDL_PushEvent(sizeEvent);

    c = new Context;
}

Sdl2Application::~Sdl2Application() {
    delete c;

    SDL_GL_DeleteContext(context);
    SDL_DestroyWindow(window);
    SDL_Quit();
}

int Sdl2Application::exec() {
    for(;;) {
        SDL_Event event;

        while(SDL_PollEvent(&event)) {
            switch(event.type) {
                case SDL_WINDOWEVENT:
                    switch(event.window.event) {
                        case SDL_WINDOWEVENT_RESIZED:
                            viewportEvent({event.window.data1, event.window.data2});
                            _redraw = true;
                            break;
                        case SDL_WINDOWEVENT_EXPOSED:
                            _redraw = true;
                            break;
                    } break;
                case SDL_KEYDOWN:
                case SDL_KEYUP: {
                    /*
                     * Fix up the modifiers -- we want >= operator to work
                     * properly on Shift, Ctrl, Alt, but SDL generates
                     * different event for left / right keys, thus
                     * (modifiers >= Shift) would pass only if both left and
                     * right were pressed, which is usually not what the
                     * developers wants.
                     */
                    Modifiers modifiers(static_cast<Modifier>(event.key.keysym.mod));
                    if(modifiers & Modifier::Shift) modifiers |= Modifier::Shift;
                    if(modifiers & Modifier::Ctrl) modifiers |= Modifier::Ctrl;
                    if(modifiers & Modifier::Alt) modifiers |= Modifier::Alt;

                    if(event.type == SDL_KEYDOWN)
                        keyPressEvent(static_cast<Key>(event.key.keysym.sym), modifiers, {});
                    else
                        keyReleaseEvent(static_cast<Key>(event.key.keysym.sym), modifiers, {});
                    break;
                } case SDL_MOUSEBUTTONDOWN:
                    mousePressEvent(static_cast<MouseButton>(event.button.button), Modifiers(), {event.button.x, event.button.y});
                    break;
                case SDL_MOUSEBUTTONUP:
                    mouseReleaseEvent(static_cast<MouseButton>(event.button.button), Modifiers(), {event.button.x, event.button.y});
                    break;
                case SDL_MOUSEWHEEL:
                    if(event.wheel.y != 0)
                        mousePressEvent(event.wheel.y < 0 ? MouseButton::WheelUp : MouseButton::WheelDown, Modifiers(), {event.wheel.x, event.wheel.y});
                    break;
                case SDL_MOUSEMOTION:
                    mouseMotionEvent(Modifiers(), {event.motion.x, event.motion.y});
                    break;
                case SDL_QUIT:
                    return 0;
            }
        }

        if(_redraw) {
            _redraw = false;
            drawEvent();
        } else Corrade::Utility::sleep(5);
    }

    return 0;
}

}}