/**
 * Simple Evas-3D example illustrating how to create simple mesh without any loading.
 *
 * This example is the best to start introduction to usage of Evas-3D.
 *
 * @verbatim
 * gcc -o evas-3d-cube evas-3d-cube.c `pkg-config --libs --cflags efl evas ecore ecore-evas eo`
 * @endverbatim
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#else
#define EFL_BETA_API_SUPPORT
#define EFL_EO_API_SUPPORT
#endif

#include <Eo.h>
#include <Evas.h>
#include <Ecore.h>
#include <Ecore_Evas.h>

#define  WIDTH          400
#define  HEIGHT         400

typedef struct _Scene_Data
{
   Eo *scene;
   Eo *root_node;
   Eo *camera_node;
   Eo *light_node;
   Eo *mesh_node;

   Eo *camera;
   Eo *light;
   Eo *mesh;
   Eo *material;
} Scene_Data;

static Ecore_Evas *ecore_evas = NULL;
static Evas *evas = NULL;
static Eo *background = NULL;
static Eo *image = NULL;

static const float cube_vertices[] =
{
   /* Front */
   -1.0,  1.0,  1.0,     0.0,  0.0,  1.0,     1.0, 0.0, 0.0, 1.0,     0.0,  1.0,
    1.0,  1.0,  1.0,     0.0,  0.0,  1.0,     1.0, 0.0, 0.0, 1.0,     1.0,  1.0,
   -1.0, -1.0,  1.0,     0.0,  0.0,  1.0,     1.0, 0.0, 0.0, 1.0,     0.0,  0.0,
    1.0, -1.0,  1.0,     0.0,  0.0,  1.0,     1.0, 0.0, 0.0, 1.0,     1.0,  0.0,

   /* Back */
    1.0,  1.0, -1.0,     0.0,  0.0, -1.0,     0.0, 0.0, 1.0, 1.0,     0.0,  1.0,
   -1.0,  1.0, -1.0,     0.0,  0.0, -1.0,     0.0, 0.0, 1.0, 1.0,     1.0,  1.0,
    1.0, -1.0, -1.0,     0.0,  0.0, -1.0,     0.0, 0.0, 1.0, 1.0,     0.0,  0.0,
   -1.0, -1.0, -1.0,     0.0,  0.0, -1.0,     0.0, 0.0, 1.0, 1.0,     1.0,  0.0,

   /* Left */
   -1.0,  1.0, -1.0,    -1.0,  0.0,  0.0,     0.0, 1.0, 0.0, 1.0,     0.0,  1.0,
   -1.0,  1.0,  1.0,    -1.0,  0.0,  0.0,     0.0, 1.0, 0.0, 1.0,     1.0,  1.0,
   -1.0, -1.0, -1.0,    -1.0,  0.0,  0.0,     0.0, 1.0, 0.0, 1.0,     0.0,  0.0,
   -1.0, -1.0,  1.0,    -1.0,  0.0,  0.0,     0.0, 1.0, 0.0, 1.0,     1.0,  0.0,

   /* Right */
    1.0,  1.0,  1.0,     1.0,  0.0,  0.0,     1.0, 1.0, 0.0, 1.0,     0.0,  1.0,
    1.0,  1.0, -1.0,     1.0,  0.0,  0.0,     1.0, 1.0, 0.0, 1.0,     1.0,  1.0,
    1.0, -1.0,  1.0,     1.0,  0.0,  0.0,     1.0, 1.0, 0.0, 1.0,     0.0,  0.0,
    1.0, -1.0, -1.0,     1.0,  0.0,  0.0,     1.0, 1.0, 0.0, 1.0,     1.0,  0.0,

   /* Top */
   -1.0,  1.0, -1.0,     0.0,  1.0,  0.0,     1.0, 0.0, 1.0, 1.0,     0.0,  1.0,
    1.0,  1.0, -1.0,     0.0,  1.0,  0.0,     1.0, 0.0, 1.0, 1.0,     1.0,  1.0,
   -1.0,  1.0,  1.0,     0.0,  1.0,  0.0,     1.0, 0.0, 1.0, 1.0,     0.0,  0.0,
    1.0,  1.0,  1.0,     0.0,  1.0,  0.0,     1.0, 0.0, 1.0, 1.0,     1.0,  0.0,

   /* Bottom */
    1.0, -1.0, -1.0,     0.0, -1.0,  0.0,     0.0, 1.0, 1.0, 1.0,     0.0,  1.0,
   -1.0, -1.0, -1.0,     0.0, -1.0,  0.0,     0.0, 1.0, 1.0, 1.0,     1.0,  1.0,
    1.0, -1.0,  1.0,     0.0, -1.0,  0.0,     0.0, 1.0, 1.0, 1.0,     0.0,  0.0,
   -1.0, -1.0,  1.0,     0.0, -1.0,  0.0,     0.0, 1.0, 1.0, 1.0,     1.0,  0.0,
};

static const unsigned short cube_indices[] =
{
   /* Front */
   0,   1,  2,  2,  1,  3,

   /* Back */
   4,   5,  6,  6,  5,  7,

   /* Left */
   8,   9, 10, 10,  9, 11,

   /* Right */
   12, 13, 14, 14, 13, 15,

   /* Top */
   16, 17, 18, 18, 17, 19,

   /* Bottom */
   20, 21, 22, 22, 21, 23
};

static void
_on_delete(Ecore_Evas *ee EINA_UNUSED)
{
   ecore_main_loop_quit();
}

static void
_on_canvas_resize(Ecore_Evas *ee)
{
   int w, h;

   ecore_evas_geometry_get(ee, NULL, NULL, &w, &h);
   efl_gfx_size_set(background, w, h);
   efl_gfx_size_set(image, w, h);
}

static Eina_Bool
_animate_scene(void *data)
{
   static float angle = 0.0f;
   Scene_Data *scene = (Scene_Data *)data;

   angle += 0.5;

   evas_canvas3d_node_orientation_angle_axis_set(scene->mesh_node, angle, 1.0, 1.0, 1.0);

   /* Rotate */
   if (angle > 360.0) angle -= 360.0f;

   return EINA_TRUE;
}

static void
_camera_setup(Scene_Data *data)
{
   data->camera = eo_add(EVAS_CANVAS3D_CAMERA_CLASS, evas);

   evas_canvas3d_camera_projection_perspective_set(data->camera, 60.0, 1.0, 2.0, 50.0);

   data->camera_node =
      eo_add(EVAS_CANVAS3D_NODE_CLASS, evas, evas_canvas3d_node_constructor(eo_self, EVAS_CANVAS3D_NODE_TYPE_CAMERA));
   evas_canvas3d_node_camera_set(data->camera_node, data->camera);
   evas_canvas3d_node_position_set(data->camera_node, 0.0, 0.0, 10.0);
   evas_canvas3d_node_look_at_set(data->camera_node, EVAS_CANVAS3D_SPACE_PARENT, 0.0, 0.0, 0.0, EVAS_CANVAS3D_SPACE_PARENT, 0.0, 1.0, 0.0);
   evas_canvas3d_node_member_add(data->root_node, data->camera_node);
}

static void
_light_setup(Scene_Data *data)
{
   data->light = eo_add(EVAS_CANVAS3D_LIGHT_CLASS, evas);
   evas_canvas3d_light_ambient_set(data->light, 0.2, 0.2, 0.2, 1.0);
   evas_canvas3d_light_diffuse_set(data->light, 1.0, 1.0, 1.0, 1.0);
   evas_canvas3d_light_specular_set(data->light, 1.0, 1.0, 1.0, 1.0);

   data->light_node =
      eo_add(EVAS_CANVAS3D_NODE_CLASS, evas, evas_canvas3d_node_constructor(eo_self, EVAS_CANVAS3D_NODE_TYPE_LIGHT));
   evas_canvas3d_node_light_set(data->light_node, data->light);
   evas_canvas3d_node_position_set(data->light_node, 0.0, 0.0, 10.0);
   evas_canvas3d_node_look_at_set(data->light_node, EVAS_CANVAS3D_SPACE_PARENT, 0.0, 0.0, 0.0, EVAS_CANVAS3D_SPACE_PARENT, 0.0, 1.0, 0.0);
   evas_canvas3d_node_member_add(data->root_node, data->light_node);
}
static void
_mesh_setup(Scene_Data *data)
{
   /* Setup material. */
   data->material = eo_add(EVAS_CANVAS3D_MATERIAL_CLASS, evas);

   evas_canvas3d_material_enable_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_AMBIENT, EINA_TRUE);
   evas_canvas3d_material_enable_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_DIFFUSE, EINA_TRUE);
   evas_canvas3d_material_enable_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_SPECULAR, EINA_TRUE);
   evas_canvas3d_material_color_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_AMBIENT, 0.2, 0.2, 0.2, 1.0);
   evas_canvas3d_material_color_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_DIFFUSE, 0.8, 0.8, 0.8, 1.0);
   evas_canvas3d_material_color_set(data->material, EVAS_CANVAS3D_MATERIAL_ATTRIB_SPECULAR, 1.0, 1.0, 1.0, 1.0);
   evas_canvas3d_material_shininess_set(data->material, 100.0);

   /* Setup mesh. */
   data->mesh = eo_add(EVAS_CANVAS3D_MESH_CLASS, evas);
   evas_canvas3d_mesh_vertex_count_set(data->mesh, 24);
   evas_canvas3d_mesh_frame_add(data->mesh, 0);
   evas_canvas3d_mesh_frame_vertex_data_set(data->mesh, 0, EVAS_CANVAS3D_VERTEX_ATTRIB_POSITION, 12 * sizeof(float), &cube_vertices[ 0]);
   evas_canvas3d_mesh_frame_vertex_data_set(data->mesh, 0, EVAS_CANVAS3D_VERTEX_ATTRIB_NORMAL, 12 * sizeof(float), &cube_vertices[ 3]);
   evas_canvas3d_mesh_frame_vertex_data_set(data->mesh, 0, EVAS_CANVAS3D_VERTEX_ATTRIB_COLOR, 12 * sizeof(float), &cube_vertices[ 6]);
   evas_canvas3d_mesh_frame_vertex_data_set(data->mesh, 0, EVAS_CANVAS3D_VERTEX_ATTRIB_TEXCOORD, 12 * sizeof(float), &cube_vertices[10]);
   evas_canvas3d_mesh_index_data_set(data->mesh, EVAS_CANVAS3D_INDEX_FORMAT_UNSIGNED_SHORT, 36, &cube_indices[0]);
   evas_canvas3d_mesh_vertex_assembly_set(data->mesh, EVAS_CANVAS3D_VERTEX_ASSEMBLY_TRIANGLES);
   evas_canvas3d_mesh_shader_mode_set(data->mesh, EVAS_CANVAS3D_SHADER_MODE_PHONG);
   evas_canvas3d_mesh_frame_material_set(data->mesh, 0, data->material);

   data->mesh_node =
      eo_add(EVAS_CANVAS3D_NODE_CLASS, evas, evas_canvas3d_node_constructor(eo_self, EVAS_CANVAS3D_NODE_TYPE_MESH));
   evas_canvas3d_node_member_add(data->root_node, data->mesh_node);
   evas_canvas3d_node_mesh_add(data->mesh_node, data->mesh);
}

static void
_scene_setup(Scene_Data *data)
{
   data->scene = eo_add(EVAS_CANVAS3D_SCENE_CLASS, evas);
   evas_canvas3d_scene_size_set(data->scene, WIDTH, HEIGHT);
   evas_canvas3d_scene_background_color_set(data->scene, 0.0, 0.0, 0.0, 0.0);

   data->root_node =
      eo_add(EVAS_CANVAS3D_NODE_CLASS, evas, evas_canvas3d_node_constructor(eo_self, EVAS_CANVAS3D_NODE_TYPE_NODE));

   _camera_setup(data);
   _light_setup(data);
   _mesh_setup(data);

   evas_canvas3d_scene_root_node_set(data->scene, data->root_node);
   evas_canvas3d_scene_camera_node_set(data->scene, data->camera_node);
}

int
main(void)
{
   //Unless Evas 3D supports Software renderer, we set gl backened forcely.
   setenv("ECORE_EVAS_ENGINE", "opengl_x11", 1);

   Scene_Data data;

   if (!ecore_evas_init()) return 0;

   ecore_evas = ecore_evas_new(NULL, 10, 10, WIDTH, HEIGHT, NULL);
   if (!ecore_evas) return 0;

   ecore_evas_callback_delete_request_set(ecore_evas, _on_delete);
   ecore_evas_callback_resize_set(ecore_evas, _on_canvas_resize);
   ecore_evas_show(ecore_evas);

   evas = ecore_evas_get(ecore_evas);

   _scene_setup(&data);

   /* Add a background rectangle objects. */
   background = eo_add(EFL_CANVAS_RECTANGLE_CLASS, evas);
   efl_gfx_color_set(background, 0, 0, 0, 255);
   efl_gfx_size_set(background, WIDTH, HEIGHT);
   efl_gfx_visible_set(background, EINA_TRUE);

   /* Add an image object for 3D scene rendering. */
   image = eo_add(EFL_CANVAS_SCENE3D_CLASS, evas);
   efl_gfx_size_set(image, WIDTH, HEIGHT);
   efl_gfx_visible_set(image, EINA_TRUE);

   /* Set the image object as render target for 3D scene. */
   efl_canvas_scene3d_set(image, data.scene);

   /* Add animation timer callback. */
   ecore_timer_add(0.016, _animate_scene, &data);

   /* Enter main loop. */
   ecore_main_loop_begin();

   ecore_evas_free(ecore_evas);
   ecore_evas_shutdown();

   return 0;
}