racing_game/graphics.cpp

#include <GL/glut.h>
#include <iostream>

#ifdef __linux__
#include <X11/Xlib.h>
#endif

#ifdef _WIN32
#include <Windows.h>
#endif

#include "libs/mainloop-api/mainloop.h"
#include "graphics.h"
#include "textures.h"
#include "player.h"
#include "clouds.h"
#include "world.h"

GLfloat aspect;
GLsizei w_dimentions[2];
int skymap_size[2];
int skymap_id;
int mspf=1000/30;
int max_mspf=1000/10;
int* sxy;

void on_early()
{
	// Make the display interval between updates shorter
	if(mspf > max_mspf) {
		mspf -= 1;
	}
}

void on_late()
{
	// Increase the display update intervals
	mspf += 1;
}

int* desktopResolution()
{
	// Setup the data structure
	int* data = new int[2]();

	#ifdef _WIN32

	// Get the desktop
	RECT desktop;

	// Get the desktop window
	const HWND hDesktop = GetDesktopWindow();

	// Process the size of the window
	GetWindowRect(hDesktop, &desktop);

	// Set these values
	data[0] = desktop.bottom;
	data[1] = desktop.right;

	#endif

	#ifdef __linux__

	// Get the screen
	Display* d = XOpenDisplay(NULL);
	Screen*  s = DefaultScreenOfDisplay(d);

	// Set the varibles
	data[0] = s->width;
	data[1] = s->height;

	#endif

	// Return the data
	return data;
}

void display()
{
  // Clear the screen
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// Set perspective view
	gluPerspective(100.0f, aspect, 0.1f, 100.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	// Enable depth
	glEnable(GL_DEPTH_TEST);

	/*glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glFrustum(-1.0, 1.0, -1.0, 1.0, 10.0, 8.0);*/

	// Set the viewport
	glViewport(0, 0, w_dimentions[0], w_dimentions[1]);

	// Load the skymap
	glBindTexture(GL_TEXTURE_2D, skymap_id);

	// Rotate the angle
	glRotated(player_angle[1], 1, 0, 0);
	glRotated(player_angle[0], 0, 1, 0);

	// Set the colour
	glColor4f(0.5f,0.7f,1.0f,1.0f);

	// Start drawing a cube
	glBegin(GL_QUADS);

	// Top
	glTexCoord2d(1/3.0,0); glVertex3i(-2, 1,-2);
	glTexCoord2d(0/3.0,0); glVertex3i( 2, 1,-2);
	glTexCoord2d(0/3.0,1); glVertex3i( 2, 1, 2);
	glTexCoord2d(1/3.0,1); glVertex3i(-2, 1, 2);

	// Sides

	glTexCoord2d(2/3.0,0); glVertex3i( 1,-1,-1);
	glTexCoord2d(1/3.0,0); glVertex3i( 1, 1,-1);
	glTexCoord2d(1/3.0,1); glVertex3i(-1, 1,-1);
	glTexCoord2d(2/3.0,1); glVertex3i(-1,-1,-1);

	glTexCoord2d(2/3.0,0); glVertex3i( 1,-1, 1);
	glTexCoord2d(1/3.0,0); glVertex3i( 1, 1, 1);
	glTexCoord2d(1/3.0,1); glVertex3i(-1, 1, 1);
	glTexCoord2d(2/3.0,1); glVertex3i(-1,-1, 1);

	glTexCoord2d(2/3.0,0); glVertex3i(-1,-1,-1);
	glTexCoord2d(1/3.0,0); glVertex3i(-1, 1,-1);
	glTexCoord2d(1/3.0,1); glVertex3i(-1, 1, 1);
	glTexCoord2d(2/3.0,1); glVertex3i(-1,-1, 1);

	glTexCoord2d(2/3.0,0); glVertex3i( 1,-1,-1);
	glTexCoord2d(1/3.0,0); glVertex3i( 1, 1,-1);
	glTexCoord2d(1/3.0,1); glVertex3i( 1, 1, 1);
	glTexCoord2d(2/3.0,1); glVertex3i( 1,-1, 1);

	// Bottom
	glTexCoord2d(3/3.0,0); glVertex3i(-2,-1,-2);
	glTexCoord2d(2/3.0,0); glVertex3i( 2,-1,-2);
	glTexCoord2d(2/3.0,1); glVertex3i( 2,-1, 2);
	glTexCoord2d(3/3.0,1); glVertex3i(-2,-1, 2);

	// Stop drawing the cubemap
	glEnd();

	// Clear the depth
	glClear(GL_DEPTH_BUFFER_BIT);

	// Render the clouds
	clouds_render();

	// Translate the position
	glTranslated(-player_pos[0],-player_pos[1],-player_pos[2]);

	// Load the worlds blocks
	world_render();

	glPopMatrix();

	// 2D view
	/*glMatrixMode (GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-9.0, 9.0, -9.0, 9.0, 0.0, 30.0);
	glLoadIdentity();*/

	glLoadIdentity();
	glMatrixMode(GL_PROJECTION);
	glDisable(GL_DEPTH_TEST);
	glLoadIdentity();

	//glPopMatrix();

	// Render the player
	player_render();

  // Swap the front and back frame buffers
	glutSwapBuffers();
}

void reshape(GLsizei width, GLsizei height)
{
	// Prevent division by zero
	if (width  < 1) width  = 1;
	if (height < 1) height = 1;

	w_dimentions[0] = width;
	w_dimentions[1] = height;

	// Get the aspect
	aspect = GLfloat(width) / GLfloat(height);

	// Reload the identity
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	// Set the perspective
	gluPerspective(100.0f, aspect, 0.1f, 100.0f);
}

void graphics_reshape()
{
	reshape(w_dimentions[0], w_dimentions[1]);
}

void render_event(int *args)
{
  // Repost this event
  mainloopRegAction(render_event, mspf, 0);

  // Post Redisplay
  glutPostRedisplay();
}

void display_event(int *args)
{
  // Repost this event
  mainloopRegAction(display_event, 10, 0);

  // Do the glut mainloop event
  glutMainLoopEvent();
}

void graphics_init(int argc, char *argv[])
{
  // Initialise OpenGL
  glutInit(&argc, argv);

  // Get the screen size
  sxy = desktopResolution();

  // Set the window properties
  glutCreateWindow("Racing Game");
  glutInitDisplayMode(GLUT_DOUBLE);
  glutReshapeWindow(sxy[0], sxy[1]);
  glutFullScreen();

  // Display stuff
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);

	// Enable some stuff
	glEnable(GL_TEXTURE_2D);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_NORMALIZE);

	// Enable blending
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	// Load the skymap
	skymap_id = loadArchiveImageGL("textures/sky.rimg", 'N', skymap_size[0], skymap_size[1]);

  // Make these functions happen in the future
  mainloopRegAction(display_event, 10, 0);
  mainloopRegAction(render_event, 1000/60, 0);

	// Handle lag
	mainloopOnEarly(on_early);
	mainloopOnLate(on_late);
}