draw scene

gistfile1.txt

/* draw_scene.c
 *
 * Code to draw the main scene when in flight
 *
 */
#include "main.h"

/* highly unoptimised scene rendering */
void draw_scene( void )
{
	int a;
	Vector view;
	GLfloat params;
	float r;
	GLfloat light_position[] = { 80000, 0.0, -150000.0, 1.0 }; // light at the sun position

	/* material properties */
	GLfloat sun_emission[] = { 1.0, 1.0, 1.0, 1.0 };
	GLfloat sun_specular[] = { 1.0, 1.0, 0.6, 1.0 };
	GLfloat sun_shininess[] = { 10.0 };

	GLfloat no_emission[] = { 0.0, 0.0, 0.0, 1.0 };
	GLfloat planet_diff[] = { 1.0, 1.0, 1.0, 1.0 };
	GLfloat atmos_diff[]  = { 0.5, 0.5, 1.0, 0.5 };
	GLfloat planet_spec[] = { 0.0, 0.0, 0.0, 1.0 };

	GLfloat sun_glow_diff[]  = { 1.0, 0.4, 0.4, 0.4 };
	GLfloat sun_glow_diff2[]  = { 1.0, 1.0, 0.4, 0.6 };
	GLfloat sun_diff[] = { 1.0, 1.0, 0.5, 1.0 };
	GLfloat sun_shine_pos[4];

	GLfloat ship_emission[] = { 0.0, 0.0, 0.0, 1.0 };
	GLfloat ship_diff[] = { 0.5, 0.0, 0.5, 1.0 };
	GLfloat ship_spec[] = { 0.0, 0.0, 0.0, 1.0 };


    glViewport( 0, 0, width, height );

	glMatrixMode(GL_PROJECTION); 
	glLoadIdentity();

	/* calculate the aspect ratio of the window */
	/* really big far point to accomodate the planets, it probably shouldn't be done like this */
	gluPerspective(fov, (GLfloat)width / (GLfloat)height, 0.1f, 3000000.0f);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();  
	
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glLoadIdentity();    

	if (view_dir == REAR_VIEW)
		object_rotate_y (&camera, 180.0); // this is crap

	/* calculate the view vector */
	vector_add (&view, &(camera.pos), &(camera.view));

	/* set the camera orientation */
	gluLookAt (camera.pos.x, camera.pos.y, camera.pos.z,
		           view.x, view.y, view.z,
				   camera.up.x, camera.up.y, camera.up.z);

	if (view_dir == REAR_VIEW)
		object_rotate_y (&camera, 180.0); // this is crap

	/** Skybox plotting **/
	glEnable (GL_TEXTURE_2D);
	glBindTexture (GL_TEXTURE_2D, texture[2]);  // the stars texture
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);    
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);

	/* draw the skybox as a cube around the camera */
	glPushMatrix ();
	glTranslatef (camera.pos.x, camera.pos.y, camera.pos.z);
		glBegin (GL_QUADS);

			/* front */
			glTexCoord2f (0.0, 0.0); glVertex3f (-40, -40, -40);
			glTexCoord2f (3.0, 0.0); glVertex3f ( 40, -40, -40);
			glTexCoord2f (3.0, 3.0); glVertex3f ( 40,  40, -40);
			glTexCoord2f (0.0, 3.0); glVertex3f (-40,  40, -40);

			/* back */
			glTexCoord2f (0.0, 0.0); glVertex3f ( 40, -40, 40);
			glTexCoord2f (3.0, 0.0); glVertex3f (-40, -40, 40);
			glTexCoord2f (3.0, 3.0); glVertex3f (-40,  40, 40);
			glTexCoord2f (0.0, 3.0); glVertex3f ( 40,  40, 40);

			/* right */
			glTexCoord2f (0.0, 0.0); glVertex3f (40, -40, -40);
			glTexCoord2f (3.0, 0.0); glVertex3f (40, -40,  40);
			glTexCoord2f (3.0, 3.0); glVertex3f (40,  40,  40);
			glTexCoord2f (0.0, 3.0); glVertex3f (40,  40, -40);

			/* left */ 
			glTexCoord2f (0.0, 0.0); glVertex3f (-40, -40,  40);
			glTexCoord2f (3.0, 0.0); glVertex3f (-40, -40, -40);
			glTexCoord2f (3.0, 3.0); glVertex3f (-40,  40, -40);
			glTexCoord2f (0.0, 3.0); glVertex3f (-40,  40,  40);

			/* top */
			glTexCoord2f (0.0, 0.0); glVertex3f (-40,  40, -40);
			glTexCoord2f (3.0, 0.0); glVertex3f ( 40,  40, -40);
			glTexCoord2f (3.0, 3.0); glVertex3f ( 40,  40,  40);
			glTexCoord2f (0.0, 3.0); glVertex3f (-40,  40,  40);

			/* bottom */
			glTexCoord2f (0.0, 0.0); glVertex3f (-40, -40,  40);
			glTexCoord2f (3.0, 0.0); glVertex3f ( 40, -40,  40);
			glTexCoord2f (3.0, 3.0); glVertex3f ( 40, -40, -40);
			glTexCoord2f (0.0, 3.0); glVertex3f (-40, -40, -40);

		glEnd ();
	glPopMatrix ();

	/** planet / sun plotting **/

	glEnable (GL_LIGHTING);
	glEnable (GL_LIGHT0);
	glLightfv (GL_LIGHT0, GL_POSITION, light_position);

	sun_shine_pos[0] = camera.pos.x;
	sun_shine_pos[1] = camera.pos.y;
	sun_shine_pos[2] = camera.pos.z;
	sun_shine_pos[3] = 1.0;
	
	glLightfv (GL_LIGHT1, GL_POSITION, sun_shine_pos);


	glEnable (GL_LIGHT1);
	glMaterialfv (GL_FRONT, GL_DIFFUSE, sun_diff);
	glMaterialfv (GL_FRONT, GL_EMISSION, sun_emission);
	glMaterialfv (GL_FRONT, GL_SPECULAR, sun_specular);
	glMaterialfv (GL_FRONT, GL_SHININESS, sun_shininess);

	/* plot the sun */

	glBindTexture (GL_TEXTURE_2D, texture[1]);

	glPushMatrix ();
		glTranslatef (80000, 0, -150000);
		glRotatef(90.0f,  1.0f, 0.0f, 0.0f);
		glRotatef(180,  0.0f, 0.0f, 1.0f);
		glCallList (4);
	glPopMatrix ();
	glDisable (GL_LIGHT1);

	glEnable (GL_LIGHT0);
	glMaterialfv (GL_FRONT, GL_EMISSION, no_emission);
	glMaterialfv (GL_FRONT, GL_DIFFUSE, planet_diff);
	glMaterialfv (GL_FRONT, GL_SPECULAR, planet_spec);

	/* plot the planet */
	glMaterialfv (GL_FRONT, GL_DIFFUSE, planet_diff);
	glBindTexture (GL_TEXTURE_2D, texture[0]);
	/* turn on mipmapping */
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);    
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
//	glDisable (GL_TEXTURE_2D); //temp
	glPushMatrix ();
		glTranslatef (-20000, 0, -200000);
		glRotatef(90.0f,  1.0f, 0.0f, 0.0f);
		glRotatef(earth_rot,  0.0f, 0.0f, 1.0f);
		glCallList (2);
	glPopMatrix ();
	glDisable (GL_TEXTURE_2D);

	glMaterialfv (GL_FRONT, GL_DIFFUSE, atmos_diff);
	
	glEnable(GL_BLEND); 

	/* planet atmosphere */ 
	glBlendFunc (GL_SRC_ALPHA, GL_ONE);
	glPushMatrix ();
		glTranslatef (-20000, 0, -200000);
		glCallList (3);
	glPopMatrix ();
	glDisable (GL_LIGHT0);

	glMaterialfv (GL_FRONT, GL_DIFFUSE, sun_glow_diff);
	glEnable (GL_LIGHT1);

	/* sun shine */
	glBlendFunc (GL_SRC_ALPHA, GL_ONE);
	glPushMatrix ();
		glColor4f(0.3f, 0.3f, 0.0f, 0.5f);
		glTranslatef (80000, 0, -150000);
		glCallList (5);
	glPopMatrix ();
	glMaterialfv (GL_FRONT, GL_DIFFUSE, sun_glow_diff2);
	glPushMatrix ();
		glColor4f(0.3f, 0.3f, 0.0f, 0.5f);
		glTranslatef (80000, 0, -150000);
		glCallList (6);
	glPopMatrix ();

	glDisable (GL_LIGHT1);

	glDisable (GL_BLEND);
	

	/** ships / object plotting **/
//	glEnable (GL_LIGHT0);
	glDisable (GL_LIGHTING); /* temp */

	glEnable (GL_DEPTH_TEST);
	glEnable (GL_TEXTURE_2D);

	for (a = 0; a < 4; a++)
		object_plot (&(ship[a]));

	glDisable (GL_TEXTURE_2D);
	glDisable (GL_DEPTH_TEST);

//	glDisable (GL_LIGHT0);
//	glDisable (GL_LIGHTING);


	/** 2-d drawing **/

	glMatrixMode(GL_PROJECTION);                                            // Select The Projection Matrix
	glLoadIdentity();                                                       // Reset The Projection Matrix

	gluOrtho2D (0.0, (GLdouble) width, 0.0, (GLdouble) height);
	glMatrixMode(GL_MODELVIEW);                                             // Select The Modelview Matrix
	glLoadIdentity();  

	
	/* redraw the HUD */
	hud_redraw ();

    SDL_GL_SwapBuffers( );

}