townengine/include/twn_rendering.h

#ifndef TWN_RENDERING_H
#define TWN_RENDERING_H

#include "twn_util.h"
#include "twn_option.h"
#include "twn_camera.h"
#include "twn_engine_api.h"

#include <SDL2/SDL.h>

#include <stdbool.h>

typedef struct push_sprite_args {
    char *path;
    t_frect rect;

    m_option_list(
        t_frect, texture_region,
        t_color, color,
        float,   rotation,
        bool,    flip_x,
        bool,    flip_y,
        bool,    stretch )
} t_push_sprite_args;

/* pushes a sprite onto the sprite render queue */
/* this is a simplified version of push_sprite_ex for the most common case. */
/* it assumes you want no color modulation, no rotation, no flip */
TWN_API void push_sprite(t_push_sprite_args args);
#define m_sprite(...) (push_sprite((t_push_sprite_args){__VA_ARGS__}))

/* pushes a filled rectangle onto the rectangle render queue */
TWN_API void push_rectangle(t_frect rect, t_color color);

/* pushes a filled circle onto the circle render queue */
TWN_API void push_circle(t_fvec2 position, float radius, t_color color);

TWN_API void push_text(char *string, t_fvec2 position, int height_px, t_color color, const char *font_path);
TWN_API int get_text_width(char *string, int height_px, const char *font_path);

/* pushes a textured 3d triangle onto the render queue */
/* vertices are in absolute coordinates, relative to world origin */
/* texture coordinates are in pixels */
TWN_API void unfurl_triangle(const char *path,
                            t_fvec3 v0,
                            t_fvec3 v1,
                            t_fvec3 v2,
                            t_shvec2 uv0,
                            t_shvec2 uv1,
                            t_shvec2 uv2);

// TODO: decide whether it's needed to begin with?
//       intended usage for it is baked lighting, i would think.
/* pushes a colored textured 3d triangle onto the render queue */
// void unfurl_colored_triangle(const char *path,
//                              t_fvec3 v0,
//                              t_fvec3 v1,
//                              t_fvec3 v2,
//                              t_shvec2 uv0,
//                              t_shvec2 uv1,
//                              t_shvec2 uv2,
//                              t_color c0,
//                              t_color c1,
//                              t_color c2);

// TODO:
// http://www.lighthouse3d.com/opengl/billboarding/index.php?billCheat2
// void unfurl_billboard(const char *path,
//                       t_fvec3 position,
//                       t_fvec2 scaling,
//                       t_frect uvs);

/* pushes a camera state to be used for all future unfurl_* commands */
TWN_API void set_camera(const t_camera *camera);

#endif