/*
 * Copyright © 2009 Eric Anholt
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *
 */

#define GL_GLEXT_PROTOTYPES
#include <GL/glew.h>
#include <glu3.h>

struct revolved_object {
	GLuint vbo, array_obj, shadow_array_obj;
	int pos_offset, norm_offset, tangent_offset, texcoord_offset;
	int elements_offset, elements_vert_stride;
	int num_verts, num_steps;
	/* Maximum distance from center of revolution to a vertex. */
	float radius;
};

enum uniform_list {
	UNIFORM_MV,
	UNIFORM_MVP,
	UNIFORM_LIGHT_MVP,
	UNIFORM_LIGHT_EYE,
	UNIFORM_NORMAL_SAMPLER,
	UNIFORM_HEIGHTMAP_SAMPLER,
	UNIFORM_SHADOW_SAMPLER,
	UNIFORM_NI,
	UNIFORM_F0,
	UNIFORM_WARD_MM_INV,
	UNIFORM_WARD_MN_INV,
	UNIFORM_WARD_NN_INV,
	UNIFORM_MAX
};

enum ground_uniform_list {
	GROUND_UNIFORM_MV,
	GROUND_UNIFORM_MVP,
	GROUND_UNIFORM_LIGHT_EYE,
	GROUND_UNIFORM_LIGHT_MVP,
	GROUND_UNIFORM_SHADOW_SAMPLER,
	GROUND_UNIFORM_MAX
};

enum shadow_uniform_list {
	SHADOW_UNIFORM_MVP,
	SHADOW_UNIFORM_MAX
};

struct uniform_desc {
	const char *name;
	GLint location;
};

#define NUM_RINGS	27

extern struct uniform_desc uniforms[UNIFORM_MAX];
extern struct uniform_desc ground_uniforms[GROUND_UNIFORM_MAX];
extern struct uniform_desc shadow_uniforms[SHADOW_UNIFORM_MAX];
extern GLuint glass_prog, ground_prog, shadow_prog;
extern GLUmat4 projection;
extern GLUmat4 world_to_eye, world_to_shadow_texcoords;
extern GLUvec4 light_world, light_eye;
extern GLUmat4 ring_obj_to_world[NUM_RINGS];
extern struct revolved_object ring;
extern GLUvec4 ring_bounding_sphere_center_world;
extern float ring_bounding_sphere_radius;
extern GLuint shadow_tex;
extern GLUmat4 world_to_light_ndc;
extern int no_multi_draw_arrays;

void do_ring_drawelements(void);

/* matrix.c */
void mult_m4_p4(float *result, const float *mat4, const float *point4);
void mult_m4_m4(float *result, const float *a4, const float *b4);
void init_m4_x_rotate(float *mat4, float x_rads);
void init_m4_y_rotate(float *mat4, float y_rads);
void init_m4_z_rotate(float *mat4, float z_rads);
void init_m4_translate(float *mat4, float x, float y, float z);
void init_m4_perspective(float *mat4, float fovy, float aspect,
			 float near, float far);
void print_m4(const float *mat4, const char *name);
void print_GLUvec4(char *desc, const GLUvec4 *vec);
void print_GLUmat4(char *desc, const GLUmat4 *m);
void make_sphere_frustum(GLUmat4 *mat,
			 GLUvec4 *center,
			 float radius);

/* load_texture.c */
GLuint load_texture_rgb(const char *filename);

/* ground.c */
void draw_ground(void);
void setup_ground(void);

/* rings.c */
void draw_rings(void);
void update_brdf_constants(void);
void setup_rings(void);

/* shadow_map.c */
void generate_rings_shadowmap(void);