Using CEGUI with SDL and OpenGL (Latest)

Written for CEGUI 0.8

---

Works with versions 0.8.x (stable)

Works with latest CEGUI stable!

SDL (Simple DirectMedia Layer) is an excellent library for writing portable games and other multimedia applications, but as it is a low-level library, it has no native support for GUI interfaces.

Before running I had to symlink/copy these files to current working directory of the binary:

• DejaVuSans-10.font
• DejaVuSans-12.font
• DejaVuSans.ttf
• TaharezLook.imageset
• TaharezLook.looknfeel
• TaharezLook.png

/*
 * Adapted by: Mikko Kortelainen <kordex@gmail.com>
 * Date: 20140808
 * Description: Using CEGUI with SDL and OpenGL
 */
 
#include <stdio.h>
#include <stdlib.h>
 
#include <SDL/SDL.h>
 
#include "CEGUI/CEGUI.h"
#include "CEGUI/RendererModules/OpenGL/GLRenderer.h"
 
#include <GL/gl.h>
#include <GL/glu.h>
 
std::map<SDLKey, CEGUI::Key::Scan> m_keymap;
 
void initializeKeyMap() {
  m_keymap[SDLK_1] = CEGUI::Key::One;
  m_keymap[SDLK_2] = CEGUI::Key::Two;
  m_keymap[SDLK_3] = CEGUI::Key::Three;
  m_keymap[SDLK_4] = CEGUI::Key::Four;
  m_keymap[SDLK_5] = CEGUI::Key::Five;
  m_keymap[SDLK_6] = CEGUI::Key::Six;
  m_keymap[SDLK_7] = CEGUI::Key::Seven;
  m_keymap[SDLK_8] = CEGUI::Key::Eight;
  m_keymap[SDLK_9] = CEGUI::Key::Nine;
  m_keymap[SDLK_0] = CEGUI::Key::Zero;
 
  m_keymap[SDLK_q] = CEGUI::Key::Q;
  m_keymap[SDLK_w] = CEGUI::Key::W;
  m_keymap[SDLK_e] = CEGUI::Key::E;
  m_keymap[SDLK_r] = CEGUI::Key::R;
  m_keymap[SDLK_t] = CEGUI::Key::T;
  m_keymap[SDLK_y] = CEGUI::Key::Y;
  m_keymap[SDLK_u] = CEGUI::Key::U;
  m_keymap[SDLK_i] = CEGUI::Key::I;
  m_keymap[SDLK_o] = CEGUI::Key::O;
  m_keymap[SDLK_p] = CEGUI::Key::P;
  m_keymap[SDLK_a] = CEGUI::Key::A;
  m_keymap[SDLK_s] = CEGUI::Key::S;
  m_keymap[SDLK_d] = CEGUI::Key::D;
  m_keymap[SDLK_f] = CEGUI::Key::F;
  m_keymap[SDLK_g] = CEGUI::Key::G;
  m_keymap[SDLK_h] = CEGUI::Key::H;
  m_keymap[SDLK_j] = CEGUI::Key::J;
  m_keymap[SDLK_k] = CEGUI::Key::K;
  m_keymap[SDLK_l] = CEGUI::Key::L;
  m_keymap[SDLK_z] = CEGUI::Key::Z;
  m_keymap[SDLK_x] = CEGUI::Key::X;
  m_keymap[SDLK_c] = CEGUI::Key::C;
  m_keymap[SDLK_v] = CEGUI::Key::V;
  m_keymap[SDLK_b] = CEGUI::Key::B;
  m_keymap[SDLK_n] = CEGUI::Key::N;
  m_keymap[SDLK_m] = CEGUI::Key::M;
 
  m_keymap[SDLK_COMMA] = CEGUI::Key::Comma;
  m_keymap[SDLK_PERIOD] = CEGUI::Key::Period;
  m_keymap[SDLK_SLASH] = CEGUI::Key::Slash;
  m_keymap[SDLK_BACKSLASH] = CEGUI::Key::Backslash;
  m_keymap[SDLK_MINUS] = CEGUI::Key::Minus;
  m_keymap[SDLK_EQUALS] = CEGUI::Key::Equals;
  m_keymap[SDLK_SEMICOLON] = CEGUI::Key::Semicolon;
  m_keymap[SDLK_LEFTBRACKET] = CEGUI::Key::LeftBracket;
  m_keymap[SDLK_RIGHTBRACKET] = CEGUI::Key::RightBracket;
  m_keymap[SDLK_QUOTE] = CEGUI::Key::Apostrophe;
  m_keymap[SDLK_BACKQUOTE] = CEGUI::Key::Grave;
 
  m_keymap[SDLK_RETURN] = CEGUI::Key::Return;
  m_keymap[SDLK_SPACE] = CEGUI::Key::Space;
  m_keymap[SDLK_BACKSPACE] = CEGUI::Key::Backspace;
  m_keymap[SDLK_TAB] = CEGUI::Key::Tab;
 
  m_keymap[SDLK_ESCAPE] = CEGUI::Key::Escape;
  m_keymap[SDLK_PAUSE] = CEGUI::Key::Pause;
  m_keymap[SDLK_SYSREQ] = CEGUI::Key::SysRq;
  m_keymap[SDLK_POWER] = CEGUI::Key::Power;
 
  m_keymap[SDLK_NUMLOCK] = CEGUI::Key::NumLock;
  m_keymap[SDLK_SCROLLOCK] = CEGUI::Key::ScrollLock;
 
  m_keymap[SDLK_F1] = CEGUI::Key::F1;
  m_keymap[SDLK_F2] = CEGUI::Key::F2;
  m_keymap[SDLK_F3] = CEGUI::Key::F3;
  m_keymap[SDLK_F4] = CEGUI::Key::F4;
  m_keymap[SDLK_F5] = CEGUI::Key::F5;
  m_keymap[SDLK_F6] = CEGUI::Key::F6;
  m_keymap[SDLK_F7] = CEGUI::Key::F7;
  m_keymap[SDLK_F8] = CEGUI::Key::F8;
  m_keymap[SDLK_F9] = CEGUI::Key::F9;
  m_keymap[SDLK_F10] = CEGUI::Key::F10;
  m_keymap[SDLK_F11] = CEGUI::Key::F11;
  m_keymap[SDLK_F12] = CEGUI::Key::F12;
  m_keymap[SDLK_F13] = CEGUI::Key::F13;
  m_keymap[SDLK_F14] = CEGUI::Key::F14;
  m_keymap[SDLK_F15] = CEGUI::Key::F15;
 
  m_keymap[SDLK_LCTRL] = CEGUI::Key::LeftControl;
  m_keymap[SDLK_LALT] = CEGUI::Key::LeftAlt;
  m_keymap[SDLK_LSHIFT] = CEGUI::Key::LeftShift;
  m_keymap[SDLK_LSUPER] = CEGUI::Key::LeftWindows;
  m_keymap[SDLK_RCTRL] = CEGUI::Key::RightControl;
  m_keymap[SDLK_RALT] = CEGUI::Key::RightAlt;
  m_keymap[SDLK_RSHIFT] = CEGUI::Key::RightShift;
  m_keymap[SDLK_RSUPER] = CEGUI::Key::RightWindows;
  m_keymap[SDLK_MENU] = CEGUI::Key::AppMenu;
 
  m_keymap[SDLK_KP0] = CEGUI::Key::Numpad0;
  m_keymap[SDLK_KP1] = CEGUI::Key::Numpad1;
  m_keymap[SDLK_KP2] = CEGUI::Key::Numpad2;
  m_keymap[SDLK_KP3] = CEGUI::Key::Numpad3;
  m_keymap[SDLK_KP4] = CEGUI::Key::Numpad4;
  m_keymap[SDLK_KP5] = CEGUI::Key::Numpad5;
  m_keymap[SDLK_KP6] = CEGUI::Key::Numpad6;
  m_keymap[SDLK_KP7] = CEGUI::Key::Numpad7;
  m_keymap[SDLK_KP8] = CEGUI::Key::Numpad8;
  m_keymap[SDLK_KP9] = CEGUI::Key::Numpad9;
  m_keymap[SDLK_KP_PERIOD] = CEGUI::Key::Decimal;
  m_keymap[SDLK_KP_PLUS] = CEGUI::Key::Add;
  m_keymap[SDLK_KP_MINUS] = CEGUI::Key::Subtract;
  m_keymap[SDLK_KP_MULTIPLY] = CEGUI::Key::Multiply;
  m_keymap[SDLK_KP_DIVIDE] = CEGUI::Key::Divide;
  m_keymap[SDLK_KP_ENTER] = CEGUI::Key::NumpadEnter;
 
  m_keymap[SDLK_UP] = CEGUI::Key::ArrowUp;
  m_keymap[SDLK_LEFT] = CEGUI::Key::ArrowLeft;
  m_keymap[SDLK_RIGHT] = CEGUI::Key::ArrowRight;
  m_keymap[SDLK_DOWN] = CEGUI::Key::ArrowDown;
 
  m_keymap[SDLK_HOME] = CEGUI::Key::Home;
  m_keymap[SDLK_END] = CEGUI::Key::End;
  m_keymap[SDLK_PAGEUP] = CEGUI::Key::PageUp;
  m_keymap[SDLK_PAGEDOWN] = CEGUI::Key::PageDown;
  m_keymap[SDLK_INSERT] = CEGUI::Key::Insert;
  m_keymap[SDLK_DELETE] = CEGUI::Key::Delete;
}
 
void handle_mouse_down(Uint8 button)
{
  CEGUI::GUIContext& context = CEGUI::System::getSingleton().getDefaultGUIContext(); 
	switch ( button ) {
		case SDL_BUTTON_LEFT:
			context.injectMouseButtonDown(CEGUI::LeftButton);
			break;
		case SDL_BUTTON_MIDDLE:
			context.injectMouseButtonDown(CEGUI::MiddleButton);
			break;
		case SDL_BUTTON_RIGHT:
			context.injectMouseButtonDown(CEGUI::RightButton);
			break;
 
		case SDL_BUTTON_WHEELDOWN:
			context.injectMouseWheelChange( -1 );
			break;
		case SDL_BUTTON_WHEELUP:
			context.injectMouseWheelChange( +1 );
			break;
	}
}
 
 
void handle_mouse_up(Uint8 button)
{
  CEGUI::GUIContext& context = CEGUI::System::getSingleton().getDefaultGUIContext(); 
	switch ( button )
	{
		case SDL_BUTTON_LEFT:
			context.injectMouseButtonUp(CEGUI::LeftButton);
			break;
		case SDL_BUTTON_MIDDLE:
			context.injectMouseButtonUp(CEGUI::MiddleButton);
			break;
		case SDL_BUTTON_RIGHT:
			context.injectMouseButtonUp(CEGUI::RightButton);
			break;
	}
}
 
 
void inject_input (bool & must_quit) 
{
  CEGUI::GUIContext& context = CEGUI::System::getSingleton().getDefaultGUIContext(); 
 
	initializeKeyMap();
 
	SDL_Event e;
	/* go through all available events */
	while (SDL_PollEvent(&e)) {
		/* we use a switch to determine the event type */
		switch (e.type) {
			/* mouse motion handler */
			case SDL_MOUSEMOTION:
				/* we inject the mouse position directly. */
			  //				CEGUI::System::getSingleton().injectMousePosition(static_cast<float>(e.motion.x),static_cast<float>(e.motion.y));
			  context.injectMousePosition( static_cast<float>(e.motion.x),static_cast<float>(e.motion.y) );
				break;
 
			/* mouse down handler */
			case SDL_MOUSEBUTTONDOWN:
				/* let a special function handle the mouse button down event */
				handle_mouse_down (e.button.button);
				break;
 
			/* mouse up handler */
			case SDL_MOUSEBUTTONUP:
				/* let a special function handle the mouse button up event */
				handle_mouse_up (e.button.button);
				break;
 
			/* key down */
			case SDL_KEYDOWN:
				/* to tell CEGUI that a key was pressed, we inject the scancode. */
			  //e.key.keysym.scancode
			  context.injectKeyDown(m_keymap[e.key.keysym.sym]);
				/* as for the character it's a litte more complicated.
				 * we'll use for translated unicode value.
				 * this is described in more detail below.
				 */
				if ((e.key.keysym.unicode & 0xFF80) == 0) {
					context.injectChar(e.key.keysym.unicode & 0x7F);
				}
				break;
 
			/* key up */
			case SDL_KEYUP:
				/* like before we inject the scancode directly. */
			  //e.key.keysym.scancode
				context.injectKeyUp(m_keymap[e.key.keysym.sym]);
				break;
 
			/* WM quit event occured */
			case SDL_QUIT:
				must_quit = true;
				break;
 
			case SDL_VIDEORESIZE:
			  CEGUI::System::getSingleton().notifyDisplaySizeChanged(CEGUI::Sizef(e.resize.w,e.resize.h));
				break;
		}
	}
}
 
 
void inject_time_pulse(double& last_time_pulse)
{
	/* get current "run-time" in seconds */
	double t = 0.001*SDL_GetTicks();
	/* inject the time that passed since the last call */
	CEGUI::System::getSingleton().injectTimePulse( float(t-last_time_pulse) );
	/* store the new time as the last time */
	last_time_pulse = t;
}
 
void render_gui()
{
	/* clear the colour buffer */
	glClear( GL_COLOR_BUFFER_BIT );
	/* render the GUI :) */
	CEGUI::System::getSingleton().renderAllGUIContexts();
	/* Update the screen */
	SDL_GL_SwapBuffers();
}
 
 
void main_loop () 
{
	bool must_quit = false;
	/* get "run-time" in seconds */
	double last_time_pulse = 0.001*static_cast<double>(SDL_GetTicks());
	while (!must_quit) {
		inject_input (must_quit);
		inject_time_pulse (last_time_pulse);
		render_gui ();
	}
}
 
 
 
int main (int argc, char **argv) 
{
	SDL_Surface * screen;
	atexit (SDL_Quit);
	SDL_Init (SDL_INIT_VIDEO);
	screen = SDL_SetVideoMode (600, 480, 0, SDL_OPENGL);
	if (screen == NULL) {
		/* Se ainda não der, desiste! */ 
		fprintf (stderr, "Impossível ajustar ao vídeo: %s\n", SDL_GetError ());
		exit (1);
	}
 
 
        CEGUI::OpenGLRenderer::bootstrapSystem();
	SDL_ShowCursor (SDL_DISABLE);
	SDL_EnableUNICODE (1);
	SDL_EnableKeyRepeat (SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);
 
	using namespace CEGUI;
	SchemeManager::getSingleton().createFromFile( "/opt/cegui-0.8.4/share/cegui-0/schemes/TaharezLook.scheme" );
	FontManager::getSingleton().createFromFile( "/opt/cegui-0.8.4/share/cegui-0/fonts/DejaVuSans-10.font" );
 
	System::getSingleton().getDefaultGUIContext().setDefaultFont( "DejaVuSans-10" );
	System::getSingleton().getDefaultGUIContext().getMouseCursor().setDefaultImage( "TaharezLook/MouseArrow" );
	System::getSingleton().getDefaultGUIContext().setDefaultTooltipType( "TaharezLook/Tooltip" );
 
	WindowManager& wmgr = WindowManager::getSingleton();
	Window* myRoot = wmgr.createWindow( "DefaultWindow", "root" );
	System::getSingleton().getDefaultGUIContext().setRootWindow( myRoot );
	FrameWindow* fWnd = static_cast<FrameWindow*>(
						      wmgr.createWindow( "TaharezLook/FrameWindow", "testWindow" ));
	myRoot->addChild( fWnd );
	// position a quarter of the way in from the top-left of parent.
	fWnd->setPosition( UVector2( UDim( 0.25f, 0.0f ), UDim( 0.25f, 0.0f ) ) );
	// set size to be half the size of the parent
	fWnd->setSize( USize( UDim( 0.5f, 0.0f ), UDim( 0.5f, 0.0f ) ) );
	fWnd->setText( "Hello World!" );
 
 
	main_loop();
}