path: root/src/render.c

/*
 * render.c
 *
 * Render the scene
 *
 * (c) 2008 Thomas White <taw27@cam.ac.uk>
 *
 *  thrust3d - a silly game
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <glew.h>
#include <glu.h>
#include <SDL.h>
#include <math.h>
#include <stdio.h>

#include "model.h"
#include "game.h"
#include "render.h"
#include "texture.h"
#include "utils.h"
#include "render-text.h"

#define PANEL_ALPHA 0.3

/* Utility function to load and compile a shader, checking the info log */
static GLuint render_load_shader(const char *filename, GLenum type) {

	GLuint shader;
	char text[4096];
	size_t len;
	FILE *fh;
	int l;
	GLint status;
	
	fh = fopen(filename, "r");
	if ( fh == NULL ) {
		fprintf(stderr, "Couldn't load shader '%s'\n", filename);
		return 0;
	}
	len = fread(text, 1, 4095, fh);
	fclose(fh);
	text[len] = '\0';
	const GLchar *source = text;
	shader = glCreateShader(type);
	glShaderSource(shader, 1, &source, NULL);
	glCompileShader(shader);
	glGetShaderiv(shader, GL_COMPILE_STATUS, &status); 
	if ( status == GL_FALSE ) {
		glGetShaderInfoLog(shader, 4095, &l, text);
		if ( l > 0 ) {
			printf("%s\n", text); fflush(stdout);
		} else {
			printf("Shader compilation failed.\n");
		}
	}
	
	return shader;
	
}

static int render_validate_shader(GLuint shader) {
	
	GLint status;
	int l;
	char text[4096];
	
	glValidateProgram(shader);
	glGetProgramiv(shader, GL_VALIDATE_STATUS, &status); 
	if ( status == GL_FALSE ) {
		glGetProgramInfoLog(shader, 4095, &l, text);
		if ( l > 0 ) {
			printf("%s\n", text); fflush(stdout);
		} else {
			printf("Shader did not validate successfully.\n");
		}
		return 0;
	}
	
	return 1;
	
}

static void render_load_shaders(RenderContext *r) {
	
	/* Lighting */
	r->lighting_vert = render_load_shader(DATADIR"/shaders/lighting.vert", GL_VERTEX_SHADER);
	r->lighting_frag = render_load_shader(DATADIR"/shaders/lighting.frag", GL_FRAGMENT_SHADER);
	r->lighting_program = glCreateProgram();
	glAttachShader(r->lighting_program, r->lighting_vert);
	glAttachShader(r->lighting_program, r->lighting_frag);
	glLinkProgram(r->lighting_program);
	render_validate_shader(r->lighting_program);
	
	/* Swirlyness */
	r->swirly_vert = render_load_shader(DATADIR"/shaders/swirlytron.vert", GL_VERTEX_SHADER);
	r->swirly_frag = render_load_shader(DATADIR"/shaders/swirlytron.frag", GL_FRAGMENT_SHADER);
	r->swirly_program = glCreateProgram();
	glAttachShader(r->swirly_program, r->swirly_vert);
	glAttachShader(r->swirly_program, r->swirly_frag);
	glLinkProgram(r->swirly_program);
	render_validate_shader(r->swirly_program);
	
}

static void render_delete_shaders(RenderContext *r) {

	glDetachShader(r->lighting_program, r->lighting_frag);
	glDetachShader(r->lighting_program, r->lighting_vert);
	glDeleteShader(r->lighting_vert);
	glDeleteShader(r->lighting_frag);
	glDeleteProgram(r->lighting_program);
	
}

#define HEMI_ROUND_BITS 16
#define HEMI_UP_BITS 8
#define HEMI_NUM_VERTICES (4 * HEMI_ROUND_BITS * HEMI_UP_BITS)
#define ADD_VERTEX 			\
	r->hemisphere_v[3*i + 0] = xv;	\
	r->hemisphere_v[3*i + 1] = yv;	\
	r->hemisphere_v[3*i + 2] = zv;	\
	r->hemisphere_n[3*i + 0] = xv;	\
	r->hemisphere_n[3*i + 1] = yv;	\
	r->hemisphere_n[3*i + 2] = zv;	\
	r->hemisphere_t[2*i + 0] = 0.5 + 0.5*sin(xv);  \
	r->hemisphere_t[2*i + 1] = 0.5 + 0.5*sin(yv);  \
	i++;

/* OpenGL initial setup */
RenderContext *render_setup(int width, int height, int disable_vbos, int disable_fbos, int disable_shaders) {
	
	RenderContext *r;
	
	r = malloc(sizeof(RenderContext));
	if ( r == NULL ) return NULL;
	
	glewInit();
	
	if ( disable_vbos == 0 ) {
		if ( GLEW_VERSION_1_5 || GLEW_ARB_vertex_buffer_object ) {
			r->vbos = 1;
		} else {
			r->vbos = 0;
			fprintf(stderr, "Vertex buffer objects are not supported by your graphics card (or maybe just by its driver).\n");
			fprintf(stderr, " -> Geometry performance may be less than optimal.\n");
		}
	} else {
		printf("The use of vertex buffer objects has been disabled at your request.\n");
		r->vbos = 0;
	}
	if ( r->vbos == 0 ) {
		fprintf(stderr, " -> Geometry performance may be less than optimal.\n");
	}
	
	if ( disable_fbos == 0 ) {
		if ( GLEW_EXT_framebuffer_object ) {
			r->fbos = 1;
		} else {
			r->fbos = 0;
			fprintf(stderr, "Framebuffer objects are not supported by your graphics card (or maybe just by its driver).\n");
		}
	} else {
		printf("The use of framebuffer objects has been disabled at your request.\n");
		r->fbos = 0;
	}
	if ( r->fbos == 0 ) {
		fprintf(stderr, " -> Reflections and GPU dynamic textures disabled.\n");
	}
	
	if ( disable_shaders == 0 ) {
		if ( ( GLEW_ARB_vertex_shader && GLEW_ARB_fragment_shader && GLEW_ARB_shader_objects && GLEW_ARB_shading_language_100 )
			|| GLEW_VERSION_2_0 ) {
			r->shaders = 1;
		} else {
			r->shaders = 0;
			fprintf(stderr, "Shaders are not supported by your graphics card (or maybe just by its driver).\n");
		}
	} else {
		printf("The use of shaders has been disabled at your request.\n");
		r->shaders = 0;
	}
	if ( r->shaders == 0 ) {
		fprintf(stderr, " -> Per-fragment lighting and GPU dynamic textures disabled.\n");
	}
	
	r->width = width;
	r->height = height;
	r->aspect = (GLfloat)width/(GLfloat)height;
	
	glClearColor(0.0, 0.0, 0.0, 1.0);
	
	glEnable(GL_COLOR_MATERIAL);
	glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
	
	glFrontFace(GL_CCW);
	glEnable(GL_CULL_FACE);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_LIGHTING);
	
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	
	if ( r->fbos ) {
	
		/* FBO for rendering swirlyness */
		glGenFramebuffersEXT(1, &r->swirly_fbo);
		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
	 	/* Add a (texture) colour buffer to the FBO */
		glGenTextures(1, &r->swirly_texture);
		glBindTexture(GL_TEXTURE_2D, r->swirly_texture);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, r->swirly_texture, 0);
		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
		
	}
	
	/* Create coordinates for a hemisphere to reuse later */
	r->hemisphere_v = malloc(3*HEMI_NUM_VERTICES*sizeof(GLfloat));
	r->hemisphere_n = malloc(3*HEMI_NUM_VERTICES*sizeof(GLfloat));
	r->hemisphere_t = malloc(2*HEMI_NUM_VERTICES*sizeof(GLfloat));
	double step_up = M_PI_2/(double)HEMI_UP_BITS;
	double step_round = 2*M_PI/(double)HEMI_ROUND_BITS;
	int is, js;
	int i = 0;
	for ( is=0; is<HEMI_ROUND_BITS; is++ ) {
		for ( js=0; js<HEMI_UP_BITS; js++ ) {
			double theta, phi;
			GLfloat xv, yv, zv;
			theta = (2*M_PI/(double)HEMI_ROUND_BITS) * (double)is;
			phi = (M_PI_2/(double)HEMI_UP_BITS) * (double)js;
			xv = cos(theta)*cos(phi);
			yv = sin(theta)*cos(phi);
			zv = sin(phi);
			ADD_VERTEX
			xv = cos(theta+step_round)*cos(phi);
			yv = sin(theta+step_round)*cos(phi);
			zv = sin(phi);
			ADD_VERTEX
			xv = cos(theta+step_round)*cos(phi+step_up);
			yv = sin(theta+step_round)*cos(phi+step_up);
			zv = sin(phi+step_up);
			ADD_VERTEX
			xv = cos(theta)*cos(phi+step_up);
			yv = sin(theta)*cos(phi+step_up);
			zv = sin(phi+step_up);
			ADD_VERTEX
		}
	}
	
	if ( r->shaders ) render_load_shaders(r);
	
	r->num_textures = 0;
	
	/* Load misc texture bits */
	texture_load(r, "radioactive");
	texture_load(r, "fuel");
	
	render_text_setup(r);
	
	return r;
	
}

void render_shutdown(RenderContext *r) {
	if ( r->shaders ) render_delete_shaders(r);
	texture_free_all(r);
}

static GLenum render_gltype(PrimitiveType type) {

	switch ( type ) {
		case PRIMITIVE_QUADS : return GL_QUADS;
		case PRIMITIVE_TRIANGLES : return GL_TRIANGLES;
		default : break;
	}

	return GL_FALSE;

}

static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderContext *r, int *nvert, GLfloat alpha) {

	int j;
	Model *m;
	GLfloat x, y, z;
	GLfloat black[] = {0.0, 0.0, 0.0, 1.0};
	int wibble;
	
	if ( r->shaders ) glUniform1f(glGetUniformLocation(r->lighting_program, "alpha"), alpha);
	
	if ( nvert == NULL ) nvert = &wibble;
	
	m = instance->model;
	if ( m == NULL ) return 0;	/* No model to draw */
	x = instance->x;
	y = instance->y;
	z = instance->z;
	
	for ( j=0; j<m->num_primitives; j++ ) {
		
		Primitive *p;
		
		p = m->primitives[j];
		
		if ( ((p->attribs & ATTRIB_PULSE) && !(p->attribs & ATTRIB_SWIRLY)) || ((p->attribs & ATTRIB_SWIRLY) && !(r->fbos && r->shaders)) ) {
			float s;
			s = fabsf(0.4*cosf(t * 0.001));
			GLfloat c[] = {s*p->col_r, s*p->col_g, s*p->col_b, 1.0};
			glMaterialfv(GL_FRONT, GL_EMISSION, c);
			glColor4f(0.3, 0.3, 0.3, alpha);
		} else if ( (p->attribs & ATTRIB_COLOUR) && !(p->attribs & ATTRIB_SWIRLY) ) {
			glMaterialfv(GL_FRONT, GL_EMISSION, black);
			glColor4f(p->col_r, p->col_g, p->col_b, alpha);
		} else {
			glMaterialfv(GL_FRONT, GL_EMISSION, black);
			glColor4f(1.0, 1.0, 1.0, alpha);
		}
		
		/* Set specular colour and shininess if required */
		if ( p->attribs & ATTRIB_SHINY ) {
			GLfloat white[] = {1.0, 1.0, 1.0, 1.0};
			glMaterialfv(GL_FRONT, GL_SPECULAR, white);
			glMaterialf(GL_FRONT, GL_SHININESS, p->shininess);	/* FIXME: Shader ignores this value */
		} else {
			glMaterialfv(GL_FRONT, GL_SPECULAR, black);
		}
		
		if ( p->type != PRIMITIVE_HEMISPHERE ) {

			/* Location and orientation */
			glPushMatrix();
			glTranslatef(x, y, z);
			glRotatef(rad2deg(instance->yaw), 0.0, 0.0, -1.0);	/* Minus sign defines +yaw as "right" */
			
			/* Texture */
			if ( p->attribs & ATTRIB_SWIRLY ) {
				if ( r->fbos && r->shaders ) {
					glBindTexture(GL_TEXTURE_2D, r->swirly_texture);
					glEnable(GL_TEXTURE_2D);
					glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
					glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
					glUniform1i(glGetUniformLocation(r->lighting_program, "texture_emits"), 1);
				} else {
					if ( r->shaders ) {
						glUniform1i(glGetUniformLocation(r->lighting_program, "texture_enabled"), 0);
					} /* else don't enable texturing */
				}
			} else if ( p->texture != NULL ) {
				Texture *texture;
				texture = texture_lookup(r, p->texture);
				if ( texture != NULL ) {
					glBindTexture(GL_TEXTURE_2D, texture->texname);
					glEnable(GL_TEXTURE_2D);
					glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
					if ( r->shaders ) glUniform1i(glGetUniformLocation(r->lighting_program, "texture_enabled"), 1);
				} else {
					if ( r->shaders ) glUniform1i(glGetUniformLocation(r->lighting_program, "texture_enabled"), 0);
				}
			} else {
				if ( r->shaders ) glUniform1i(glGetUniformLocation(r->lighting_program, "texture_enabled"), 0);
			}
			if ( r->vbos ) {
				glBindBuffer(GL_ARRAY_BUFFER, p->vertices_buffer);
				glVertexPointer(3, GL_FLOAT, 0, NULL);
				glBindBuffer(GL_ARRAY_BUFFER, p->normals_buffer);
				glNormalPointer(GL_FLOAT, 0, NULL);
				glBindBuffer(GL_ARRAY_BUFFER, p->texcoords_buffer);
				glTexCoordPointer(2, GL_FLOAT, 0, NULL);
				glBindBuffer(GL_ARRAY_BUFFER, 0);
			} else {
				glVertexPointer(3, GL_FLOAT, 0, p->vertices);
				glNormalPointer(GL_FLOAT, 0, p->normals);
				glTexCoordPointer(2, GL_FLOAT, 0, p->texcoords);
			}
			glDrawArrays(render_gltype(p->type), 0, p->num_vertices);
			*nvert += p->num_vertices;
			glDisable(GL_TEXTURE_2D);
			glPopMatrix();
			
			if ( p->attribs & ATTRIB_SWIRLY ) {
				if ( r->shaders ) glUniform1i(glGetUniformLocation(r->lighting_program, "texture_emits"), 0);
			}
			
		} else {
		
			glPushMatrix();
			glTranslatef(x+p->vertices[0], y+p->vertices[1], z+p->vertices[2]);
			glScalef(p->radius, p->radius, p->radius);
			glRotatef(rad2deg(instance->yaw), 0.0, 0.0, -1.0);	/* Minus sign defines +yaw as "right" */
			
			glEnable(GL_RESCALE_NORMAL);
			
			glVertexPointer(3, GL_FLOAT, 0, r->hemisphere_v);
			glNormalPointer(GL_FLOAT, 0, r->hemisphere_n);
			glTexCoordPointer(2, GL_FLOAT, 0, r->hemisphere_t);
			
			glDrawArrays(GL_QUADS, 0, HEMI_NUM_VERTICES);
			*nvert += HEMI_NUM_VERTICES;
			if ( r->shaders ) glUniform1i(glGetUniformLocation(r->lighting_program, "texture_emits"), 0);
			
			glDisable(GL_RESCALE_NORMAL);
			
			glPopMatrix();
			
		}

	}
	
	return 0;

}

static void render_draw_line(GLfloat x1, GLfloat y1, GLfloat z1, GLfloat x2, GLfloat y2, GLfloat z2) {

	GLfloat col[] = {0.0, 0.3, 0.0, 1.0};

	glMaterialfv(GL_FRONT, GL_EMISSION, col);
	glColor3f(0.0, 0.0, 0.0);
	
	glBegin(GL_LINES);
		glVertex3f(x1, y1, z1);
		glVertex3f(x2, y2, z2);
	glEnd();

}

static void render_draw_stuff(Game *game, Uint32 t, GLfloat alpha) {
	
	int i;
	int nvert = 0;
	
	glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	
	for ( i=0; i<game->num_rooms; i++ ) {
	
		Room *room;
		int j;
		
		room = game->rooms[i];
		if ( room == NULL ) return;
		
		//render_setup_lighting(game, room);
		
		for ( j=0; j<room->num_objects; j++ ) {
			GLfloat x, y, z;
			if ( room->objects[j] == NULL ) continue;
			x = room->rx - game->cur_room_x;
			y = room->ry - game->cur_room_y;
			z = room->rz - game->cur_room_z;
			glPushMatrix();
			glTranslatef(10.0*x, 10.0*y, 10.0*z);
			render_model_instance_draw(room->objects[j], t, game->render, &nvert, alpha);
			glPopMatrix();
		}
		
	}
	
	//printf("%i ***\n", nvert);
	
	glPopClientAttrib();
	
}

static void render_setup_lighting(Game *game) {

	GLfloat pos[4];
	GLfloat dir[3];
	GLfloat ambient[4] = { 0.0, 0.0, 0.0, 1.0 };
	GLfloat diffuse[4];
	GLfloat specular[4];
	
	glEnable(GL_LIGHTING);
	
	/* Set a very dull background */
	ambient[0] = 0.07;  ambient[1] = 0.07;  ambient[2] = 0.07;  ambient[3] = 1.0;
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
	
	/* All lights have zero ambient (shader will ignore them) */
	ambient[0] = 0.0;  ambient[1] = 0.0;  ambient[2] = 0.0;
	
	/* Lander craft's headlight */
	pos[0] = game->lander->x;
	pos[1] = game->lander->y;
	pos[2] = game->lander->z+0.3;
	pos[3] = 1.0;
	glLightfv(GL_LIGHT0, GL_POSITION, pos);
	dir[0] = sinf(game->lander->yaw);
	dir[1] = cosf(game->lander->yaw);
	dir[2] = 0.0;
	dir[3] = 1.0;
	glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, dir);
	glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, 45.0);
	glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, 20.0);
	glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 1.0);
	glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 0.02);
	glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.005);
	/* Headlight colours */
	glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);	/* Initialised to zero above */
	diffuse[0] = 1.0;  diffuse[1] = 1.0;  diffuse[2] = 1.0;  diffuse[3] = 1.0;
	glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
	specular[0] = 1.0;  specular[1] = 1.0;  specular[2] = 1.0;  specular[3] = 1.0;
	glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
	glEnable(GL_LIGHT0);
	
	/* A very dim fill-in light.  Adds a tiny amount of shape to things, and lifts the floor a little */
	glLightfv(GL_LIGHT1, GL_AMBIENT, ambient);	/* Initialised to zero above */
	pos[0] = -1.0;  pos[1] = 0.8;  pos[2] = 4.0;  pos[3] = 0.0;
	glLightfv(GL_LIGHT1, GL_POSITION, pos);
	diffuse[0] = 0.05;  diffuse[1] = 0.05;  diffuse[2] = 0.05;  diffuse[3] = 1.0;
	glLightfv(GL_LIGHT1, GL_DIFFUSE, diffuse);
	specular[0] = 0.0;  specular[1] = 0.0;  specular[2] = 0.0;  specular[3] = 1.0;
	glLightfv(GL_LIGHT1, GL_SPECULAR, specular);
	glEnable(GL_LIGHT1);
	
	/* A fill-in light, only used on its own, to light the lander craft itself */
	glLightfv(GL_LIGHT2, GL_AMBIENT, ambient);	/* Initialised to zero above */
	pos[0] = -1.0;  pos[1] = 0.8;  pos[2] = 4.0;  pos[3] = 0.0;
	glLightfv(GL_LIGHT2, GL_POSITION, pos);
	diffuse[0] = 0.3;  diffuse[1] = 0.3;  diffuse[2] = 0.3;  diffuse[3] = 1.0;
	glLightfv(GL_LIGHT2, GL_DIFFUSE, diffuse);
	specular[0] = 1.0;  specular[1] = 1.0;  specular[2] = 1.0;  specular[3] = 1.0;
	glLightfv(GL_LIGHT2, GL_SPECULAR, specular);

}

void render_set_wireframe(int wireframe) {

	if ( wireframe != 0 ) {
		glPolygonMode(GL_FRONT, GL_LINE);
	} else {
		glPolygonMode(GL_FRONT, GL_FILL);
	}
	
}

static void render_draw_2d(RenderContext *r, Game *game) {

	Texture *texture;
	GLfloat cr, cg, cb;
	
	/* Set up transforms for 2D rendering */
	glClear(GL_DEPTH_BUFFER_BIT);
	glDisable(GL_LIGHTING);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glScalef(0.95, 0.95, 1.0);
	
	/* Radiation symbol */
	texture = texture_lookup(r, "radioactive");
	if ( texture != NULL ) {
		glBindTexture(GL_TEXTURE_2D, texture->texname);
		glEnable(GL_TEXTURE_2D);
		glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
	}
	glColor4f(1.0, 1.0, 1.0, PANEL_ALPHA);
	glBegin(GL_QUADS);	
		glTexCoord2f(0.0, 0.0);
		glVertex2f(-1.0, -1.0);			/* Bottom left */
		glTexCoord2f(1.0, 0.0);
		glVertex2f(-0.9, -1.0);			/* Bottom right */
		glTexCoord2f(1.0, 1.0);
		glVertex2f(-0.9, -1.0+0.1*r->aspect);	/* Top right */ 
		glTexCoord2f(0.0, 1.0);
		glVertex2f(-1.0, -1.0+0.1*r->aspect);	/* Top left */
	glEnd();
	glDisable(GL_TEXTURE_2D);
	
	/* Radiation meter */
	cg = 1.0 - game->radiation;
	glBegin(GL_QUADS);	
		glColor4f(1.0, 1.0, 0.0, PANEL_ALPHA);
		glVertex2f(-1.0, -0.8);			/* Bottom left */
		glVertex2f(-0.9, -0.8);			/* Bottom right */
		glColor4f(0.8, cg, 0.0, PANEL_ALPHA);
		glVertex2f(-0.9, -0.8+(1.8*game->radiation));	/* Top right */ 
		glVertex2f(-1.0,  -0.8+(1.8*game->radiation));	/* Top left */
	glEnd();

	/* Fuel symbol */
	texture = texture_lookup(r, "fuel");
	if ( texture != NULL ) {
		glBindTexture(GL_TEXTURE_2D, texture->texname);
		glEnable(GL_TEXTURE_2D);
		glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
	}
	glColor4f(1.0, 1.0, 1.0, PANEL_ALPHA);
	glBegin(GL_QUADS);	
		glTexCoord2f(0.0, 0.0);
		glVertex2f(0.9, -1.0);			/* Bottom left */
		glTexCoord2f(1.0, 0.0);
		glVertex2f(1.0, -1.0);			/* Bottom right */
		glTexCoord2f(1.0, 1.0);
		glVertex2f(1.0, -1.0+0.1*r->aspect);	/* Top right */ 
		glTexCoord2f(0.0, 1.0);
		glVertex2f(0.9, -1.0+0.1*r->aspect);	/* Top left */
	glEnd();
	glDisable(GL_TEXTURE_2D);
	
	/* Fuel meter */
	cr = 1.0 - game->fuel;
	cg = game->fuel;
	cb = 0.2 + 0.1*game->fuel;
	glBegin(GL_QUADS);	
		glColor4f(1.0, 0.0, 0.2, PANEL_ALPHA);
		glVertex2f(0.9, -0.8);			/* Bottom left */
		glVertex2f(1.0, -0.8);			/* Bottom right */
		glColor4f(cr, cg, cb, PANEL_ALPHA);
		glVertex2f(1.0, -0.8+(1.8*game->fuel));	/* Top right */ 
		glVertex2f(0.9, -0.8+(1.8*game->fuel));	/* Top left */
	glEnd();
	
	Room *room;
	room = game_find_room(game, game->cur_room_x, game->cur_room_y, game->cur_room_z);
	if ( room != NULL ) {
		if ( room->comment != NULL ) render_text_write(-1.0, 1.0, room->comment, r);
	}
	
}

void render_draw(Game *game, Uint32 t) {

	RenderContext *r;
	GLfloat amb[] = { 0.0, 0.0, 0.0, 1.0 };
	
	r = game->render;

	if ( r->fbos ) {
		
		/* Render some swirlyness */
		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
		glClear(GL_COLOR_BUFFER_BIT);
		glViewport(0, 0, 64, 64);
		if ( r->shaders ) glUseProgram(r->swirly_program);
		if ( r->shaders ) glUniform1f(glGetUniformLocation(game->render->swirly_program, "time"), t);
		if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->swirly_program, "landed"), game->lander->recharging);
		if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->swirly_program, "rechargeripple"), game->lander->recharging);
		if ( r->shaders ) glUniform2f(glGetUniformLocation(game->render->swirly_program, "lander"), game->platform_rel_x, game->platform_rel_y);
		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		glBegin(GL_QUADS);
			glVertex2f(-1.0, -1.0);
			glVertex2f(+1.0, -1.0);
			glVertex2f(+1.0, +1.0);
			glVertex2f(-1.0, +1.0);
		glEnd();
	
		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
	
	}
	
	/* Main view */
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glViewport(0, 0, r->width, r->height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(50.0, (GLfloat)r->width/(GLfloat)r->height, 0.1, 100.0);	/* Depth buffer 10cm to 100m */
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(game->lander->x-(game->view_dist*sinf(game->lander->yaw)*cosf(game->view_angle)),
		  game->lander->y-(game->view_dist*cosf(game->lander->yaw)*cosf(game->view_angle)),
		  game->lander->z+(game->view_dist*sinf(game->view_angle)),
		  game->lander->x, game->lander->y, game->lander->z,
		  sqrtf(2.0)*sinf(game->lander->yaw)*sinf(game->view_angle),
		  sqrtf(2.0)*cosf(game->lander->yaw)*sinf(game->view_angle), sqrtf(2.0)*cosf(game->view_angle));	
	if ( r->shaders ) glUseProgram(r->lighting_program);
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "texture"), 0); /* Using GL_TEXTURE0 */
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "texture_only"), 0);
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "texture_enabled"), 1);
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "fill_light_enabled"), 0);
	render_setup_lighting(game);
	amb[0] = 0.02;  amb[1] = 0.02;  amb[2] = 0.02;
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
	render_draw_stuff(game, t, 1.0);
	
	/* Draw the lander */
	glEnable(GL_LIGHT2);
	glDisable(GL_LIGHT0);
	glDisable(GL_LIGHT1);
	glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "fill_light_enabled"), 1);
	render_model_instance_draw(game->lander, t, r, NULL, 1.0);
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "fill_light_enabled"), 0);
	glPopClientAttrib();
	if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->lighting_program, "texture_enabled"), 0);
	render_draw_line(game->lander->x, game->lander->y, game->lander->z, game->lander->x, game->lander->y, game->lander->z-200.0);
	glDisable(GL_LIGHT2);
	
	/* Back faces (done last to make blending work properly) */
	if ( r->shaders ) glUseProgram(0);	/* Speed things up a bit by not using per-fragment lighting for back faces */
	glFrontFace(GL_CW);
	glPolygonOffset(1.0, 1.0);
	glEnable(GL_POLYGON_OFFSET_FILL);
	render_setup_lighting(game);
	amb[0] = 0.1;  amb[1] = 0.1;  amb[2] = 0.1;
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
	render_draw_stuff(game, t, 0.5);
	glDisable(GL_POLYGON_OFFSET_FILL);
	glFrontFace(GL_CCW);
	
	render_draw_2d(r, game);
	
	SDL_GL_SwapBuffers();
	
}