fysxasteroids/engine/ViewBase.cc

#include "ViewBase.h"

#include "ModelBase.h"
#include "ControllerBase.h"
#include "CameraBase.h"
#include "OverlayBase.h"

#include "SimpleConsoleOverlay.h"
#include "OGLFT.h"

#include <GL/gl.h>
#include <GL/glu.h>

#include "DrawingsGL.h"

using namespace std;

namespace Engine {

static ViewBase* ViewInstance = NULL;

void InitGL () {
	glClearColor(0.3f, 0.3f, 0.3f, 1.0f);
	glClearDepth(1.0);
	glDepthFunc(GL_LESS);
	glEnable(GL_DEPTH_TEST);
	glShadeModel(GL_SMOOTH);
	glEnable (GL_CULL_FACE);
	glDisable (GL_FOG);

	glMatrixMode (GL_PROJECTION);
	glLoadIdentity ();
	glMatrixMode (GL_MODELVIEW);
	glLoadIdentity ();
}

/*
 * Inherited Module functions
 */
int ViewBase::OnInit (int argc, char* argv[]) {
	LogMessage ("View Init");

	mWindowHeight = VIEW_DEFAULT_HEIGHT;
	mWindowWidth = VIEW_DEFAULT_WIDTH;

	SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

	if( SDL_SetVideoMode( mWindowWidth, mWindowHeight, 16, SDL_OPENGL | SDL_RESIZABLE ) == 0 ) {
		LogError ("Video mode set failed: %s", SDL_GetError ());
		exit (-1);
	}

	InitGL ();
	Resize (mWindowWidth, mWindowHeight);

	mConsoleFont = new OGLFT::Monochrome ("./data/fonts/console.ttf", 12);

	if ( mConsoleFont == 0 || !mConsoleFont->isValid() ) {
		LogError ("Could not load font %s!", "./data/fonts/console.ttf");
		exit (-1);
	}

	OverlayBasePtr console_overlay(new SimpleConsoleOverlay);
	AddOverlay (console_overlay);

	mConsoleFont->setForegroundColor (1., 1., 1.);

	mDrawAxis = false;

	mDrawGrid = false;
	mGridSizeX = 8;
	mGridSizeZ = 8;

	ViewInstance = this;

	return 0;
}

void ViewBase::OnDestroy () {
	if (mConsoleFont )
		delete mConsoleFont;
	mConsoleFont = NULL;

	while (mOverlays.size() > 0)
		mOverlays.pop_back();

	ViewInstance = NULL;

	LogDebug ("View Destroy");
}

void ViewBase::CalcWorldCoordinates (int screen_x, int screen_y, float world_y, float *pos_out) {
	GLdouble modelMatrix[16], projMatrix[16];
	GLint viewport[4];
	GLdouble wx, wy, wz;

	glGetIntegerv (GL_VIEWPORT, viewport);
	glGetDoublev(GL_MODELVIEW_MATRIX, modelMatrix);
	glGetDoublev(GL_PROJECTION_MATRIX, projMatrix);

	int realy = viewport[3] - screen_y - 1;

	gluUnProject ((GLdouble) screen_x, (GLdouble) realy, 1.,
			modelMatrix, projMatrix, viewport, &wx, &wy, &wz);

	GLdouble t;
	GLdouble d[3];
	float	eye[3];

	mCamera->GetEye (&eye[0]);

	d[0] = wx - eye[0];
	d[1] = wy - eye[1];
	d[2] = wz - eye[2];

	assert (fabs (d[1]) >= 1.0e-3);
	t = -eye[1]/d[1]  + world_y;

	pos_out[0] = eye[0] + t * d[0];
	pos_out[1] = eye[1] + t * d[1];
	pos_out[2] = eye[2] + t * d[2];
}

/*
 * Module specific functions
 */
void ViewBase::UpdateCamera () {
	EntityPhysicState* player_ent = GetEntityPhysicState (GetPlayerEntityId());

	if (!player_ent) {
		LogError ("Could not call Model::PositionCamera(): player entity not found!");
		exit (-1);
	}
	vector3d entity_camera_distance (-2, 3, 0);
	vector3d entity_position = player_ent->GetPosition();
	player_ent->Globalize (entity_camera_distance);

	mCamera->SetEye (
			entity_camera_distance[0],
			entity_camera_distance[1],
			entity_camera_distance[2]
			);
	mCamera->SetPointOfIntrest (
			entity_position[0],
			entity_position[1],
			entity_position[2]
			);

	mCamera->Update ();
}

void ViewBase::Draw () {
	// Clear the screen
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// update the frame rate counter
	static Uint32 this_frame_ticks;
	static Uint32 last_frame_ticks = 0;
	static Uint32 last_fps_update = 0;
	static int frame_counter = 0;

  this_frame_ticks = SDL_GetTicks ();
	last_fps_update += this_frame_ticks - last_frame_ticks;
	last_frame_ticks = this_frame_ticks;
	frame_counter++;

	if (last_fps_update > 1000) {
		mFrameRate = frame_counter;
		last_fps_update = 0;
		frame_counter = 0;
	}
	
	UpdateCamera ();

	if (mDrawGrid)
		DrawGrid ();

	if (mDrawAxis)
		DrawAxis ();

	DrawWorld ();

	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		(*overlay_iter)->Draw();
	}

	// and update the screen
	SDL_GL_SwapBuffers ();
}

void ViewBase::DrawGLString (float x, float y, const char* str) {
	glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
	mConsoleFont->draw (x, y, str);
}

void ViewBase::GetCamereEye (float *eye_out) {
	assert (mCamera);
	mCamera->GetEye (eye_out);
}

void ViewBase::DrawGrid () {
	float xmin, xmax, xstep, zmin, zmax, zstep;
	int i, count_x, count_z;

	xmin = -mGridSizeX;
	xmax = mGridSizeX;
	zmin = -mGridSizeZ;
	zmax = mGridSizeZ;

	count_x = mGridSizeX * 2;
	count_z = mGridSizeZ * 2;

	xstep = 1.;
	zstep = 1.;

	glColor3f (1., 1., 1.);
	glBegin (GL_LINES);
	for (i = 0; i <= count_x; i++) {
		glVertex3f (i * xstep + xmin, 0., zmin);
		glVertex3f (i * xstep + xmin, 0., zmax);
	}
	for (i = 0; i <= count_z; i++) {
		glVertex3f (xmin, 0, i * zstep + zmin);
		glVertex3f (xmax, 0, i * zstep + zmin);
	}
	glEnd ();

}

void ViewBase::DrawWorld () {
}

void ViewBase::Resize (int width, int height) {
	if (height == 0)
		height = 1;

	mWindowWidth = static_cast<unsigned int> (width);
	mWindowHeight = static_cast<unsigned int> (height);

	glViewport(0, 0, width, height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(mCamera->GetFOVY (), float (width) / float (height), 0.1, 100);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity ();

	LogDebug ("Resize to: %d x %d", mWindowWidth,mWindowHeight);

	/** \warning
	 * This call has to be made for SDL 1.2 for 1.3 there seems to be a
	 * workaround, however since I do not yet run SDL 1.3 I hold on to this.
	 * See http://lists.libsdl.org/pipermail/sdl-libsdl.org/2008-November/067306.html
	 */
	if( SDL_SetVideoMode( mWindowWidth, mWindowHeight, 16, SDL_OPENGL | SDL_RESIZABLE ) == 0 ) {
		LogError ("Video mode set failed: %s", SDL_GetError ());
		exit (-1);
	}
}

bool ViewBase::SendKeyDown (const SDL_keysym &keysym) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnKeyDown (keysym))
			return true;
	}

	return false;
}

bool ViewBase::SendKeyUp (const SDL_keysym &keysym) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnKeyUp (keysym))
			return true;
	}

	return false;
}

bool ViewBase::SendMouseButtonUp (Uint8 button, Uint16 xpos, Uint16 ypos) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnMouseButtonUp (button, xpos, ypos))
			return true;
	}

	return false;
}

bool ViewBase::SendMouseButtonDown (Uint8 button, Uint16 xpos, Uint16 ypos) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnMouseButtonDown (button, xpos, ypos))
			return true;
	}

	return false;
}

/*
 * Global functions
 */
void DrawGLString (float x, float y, const char* str) {
	if (!ViewInstance) {
		LogError ("Cannot Draw GL String: View not yet initialized!");
		return;
	}
	ViewInstance->DrawGLString (x, y, str);
}

unsigned int GetWindowWidth() {
	return ViewInstance->GetWindowWidth ();
}

unsigned int GetWindowHeight() {
	return ViewInstance->GetWindowHeight ();
}

int GetFrameRate () {
	return ViewInstance->GetFrameRate ();
}

}