#ifndef __RENDERH__
# define __RENDERH__

#include "settings.h"
#include "util.h"
#include <utility>

#include <gint/display.h>

struct camera
{
    //======= Fixed settings =======//

    /* Vertical FOV, in degrees. */
    num fov;
    void set_fov(num fov);

    /* Distance to the screen (world units). */
    num screen_distance() const { return this->_sd; }

    /* Distance to the near plane, for clipping.
       TODO: Figure out a better choice of a near plane. */
    num near_plane() const { return this->screen_distance() * num(0.25); }

    //======= World data =======//

    /* Position in space; always looking towards +z. */
    vec3 pos;
    /* Current platform (used to assign colors). */
    int platform;
    /* Vector canceling the player's angular rotation around z. */
    vec2 angle_vector;

    //======= Screen settings =======//

    /* Screen size. */
    vec2 screen_size;

private:
    num _sd;
};

struct anim
{
    /* Number of frames in the animation. */
    int frame_count;
    /* List of cropped frames. */
    image_t **frames;
    /* x/y offsets to add to desired render coordinates to render each frame
       at the proper position. */
    uint8_t *x_offsets;
    uint8_t *y_offsets;
    /* Position of the x and y anchors. */
    int16_t x_anchor;
    int16_t y_anchor;
};

struct player;

/* Move the camera to track behind a player. */
void camera_track(struct camera *, struct player const *);

/* Project a world point to the screen as viewed through a camera. The returned
   vector has its x/y members set to screen coordinates stored as num; the z
   member is kept unchanged. */
vec3 camera_project_point(struct camera *, vec3 point);

/* Optimized camera_project_point() that projects an entire prect in-place. */
void camera_project_prect(struct camera *, struct prect *rect);

/* Compute the platform's color based on the camera's angle. */
int camera_platform_color(struct camera const *camera, int platform_id);

//======= Rendering tools =======//

/* Initialize/precompute globals. */
void render_init(void);

/* Color of a blue platform at the specified world time. */
uint16_t render_color_blue_platform(num t);

/* Color of the provided platform viewed from the provided camera at the given
   world time. */
uint16_t render_platform_color(struct platform const *p,
    struct camera const *camera, num t);

/* Queue an Azur command to render the triangle defined by p1/p2/p3. Only the
   x/y coordinates are used, z is ignored. */
void render_triangle(vec3 *p1, vec3 *p2, vec3 *p3, int color);

/* Queue Azur commands to render a list of dots. Only x/y coordinates are
   used, z is ignored. */
void render_dots(std::initializer_list<vec3> const &&points);

/* Render an energy string (energy font, characters supported: 0-9.%) */
void render_energy_str(int x, int y, int halign, char const *str);

/* Render a frame of an animation. */
void render_anim_frame(int x, int y, struct anim *anim, int frame);

/* Render the blue platform particle effect at time t. If *image is NULL,
   creates it automatically. */
void render_effect_bpp(image_t **image, num t);

#endif /* __RENDERH__ */