move platformes and scenery to /apps/demos/

apps/demos/platformer/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.21)
+
+project(platformer LANGUAGES C)
+
+if(NOT CMAKE_BUILD_TYPE)
+        set(CMAKE_BUILD_TYPE Debug)
+endif()
+
+add_subdirectory($ENV{TWNROOT} $ENV{TWNBUILDDIR})
+
+set(SOURCE_FILES
+        game.c
+        state.h
+
+        player.c player.h
+        world.c world.h
+
+        scenes/scene.c scenes/scene.h
+        scenes/title.c scenes/title.h
+        scenes/ingame.c scenes/ingame.h
+)
+
+use_townengine(${PROJECT_NAME} "${SOURCE_FILES}" ${CMAKE_CURRENT_SOURCE_DIR})

apps/demos/platformer/data/packs/data.toml

@@ -0,0 +1,3 @@
+[[deps]]
+source = "../../common-data" # where does it come from, might be an url
+name = "common-data"         # should be globally unique

apps/demos/platformer/data/twn.toml

@@ -0,0 +1,11 @@
+[about]
+title = "Platfomer Demo"
+developer = "Townengine Team"
+app_id = "platformer-demo"
+dev_id = "townengine-team"
+
+[game]
+base_render_width = 640
+base_render_height = 360
+
+[engine]

apps/demos/platformer/game.c

@@ -0,0 +1,79 @@
+#include "state.h"
+#include "scenes/scene.h"
+#include "scenes/title.h"
+
+#include "twn_game_api.h"
+
+#include <stdio.h>
+#include <malloc.h>
+#include <stdint.h>
+
+
+void game_tick(void) {
+    if (ctx.initialization_needed) {
+        if (!ctx.udata) {
+            ctx.udata = ccalloc(1, sizeof (State));
+
+            State *state = ctx.udata;
+            state->ctx = &ctx;
+            state->scene = title_scene(state);
+        }
+
+        input_add_action("debug_toggle");
+        input_bind_action_control("debug_toggle", CONTROL_BACKSPACE);
+
+        input_add_action("debug_dump_atlases");
+        input_bind_action_control("debug_dump_atlases", CONTROL_HOME);
+
+        input_add_action("player_left");
+        input_bind_action_control("player_left", CONTROL_A);
+
+        input_add_action("player_right");
+        input_bind_action_control("player_right", CONTROL_D);
+
+        input_add_action("player_forward");
+        input_bind_action_control("player_forward", CONTROL_W);
+
+        input_add_action("player_backward");
+        input_bind_action_control("player_backward", CONTROL_S);
+
+        input_add_action("player_jump");
+        input_bind_action_control("player_jump", CONTROL_SPACE);
+
+        input_add_action("player_run");
+        input_bind_action_control("player_run", CONTROL_LSHIFT);
+
+        input_add_action("ui_accept");
+        input_bind_action_control("ui_accept", CONTROL_RETURN);
+
+        input_add_action("mouse_capture_toggle");
+        input_bind_action_control("mouse_capture_toggle", CONTROL_ESCAPE);
+    }
+
+    State *state = ctx.udata;
+
+    if (input_is_action_just_pressed("debug_toggle")) {
+        ctx.debug = !ctx.debug;
+    }
+
+    if (input_is_action_just_pressed("debug_dump_atlases")) {
+        textures_dump_atlases();
+    }
+
+    state->scene->tick(state);
+
+    /* there's a scene switch pending, we can do it now that the tick is done */
+    if (state->next_scene != NULL) {
+        state->scene->end(state);
+        state->scene = state->next_scene;
+        state->is_scene_switching = false;
+        state->next_scene = NULL;
+    }
+}
+
+
+void game_end(void) {
+    State *state = ctx.udata;
+    state->scene->end(state);
+    free(state);
+}

apps/demos/platformer/player.c

@@ -0,0 +1,304 @@
+#include "player.h"
+#include "world.h"
+
+#include "twn_game_api.h"
+
+#include <SDL2/SDL.h>
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <tgmath.h>
+
+
+static void update_timers(Player *player) {
+     tick_timer(&player->jump_air_timer);
+     tick_timer(&player->jump_coyote_timer);
+     tick_timer(&player->jump_buffer_timer);
+}
+
+
+static void input_move(Player *player) {
+    /* apply horizontal damping when the player stops moving */
+    /* in other words, make it decelerate to a standstill */
+    if (!input_is_action_pressed("player_left") &&
+        !input_is_action_pressed("player_right"))
+    {
+        player->dx *= player->horizontal_damping;
+    }
+
+    int input_dir = 0;
+    if (input_is_action_pressed("player_left"))
+        input_dir = -1;
+    if (input_is_action_pressed("player_right"))
+        input_dir = 1;
+    if (input_is_action_pressed("player_left") &&
+        input_is_action_pressed("player_right"))
+        input_dir = 0;
+
+    player->dx += (float)input_dir * player->run_horizontal_speed;
+    player->dx = SDL_clamp(player->dx, -player->max_dx, player->max_dx);
+
+    if (fabs(player->dx) < player->run_horizontal_speed) {
+        player->dx = 0;
+    }
+}
+
+
+static void jump(Player *player) {
+    player->jump_coyote_timer = 0;
+    player->jump_buffer_timer = 0;
+    player->dy = player->jump_force_initial;
+    player->action = PLAYER_ACTION_JUMP;
+    player->jump_air_timer = player->jump_air_ticks;
+}
+
+
+static void input_jump(Player *player) {
+    player->current_gravity_multiplier = player->jump_default_multiplier;
+
+    if (input_is_action_just_pressed("player_jump")) {
+        player->jump_air_timer = 0;
+        player->jump_buffer_timer = player->jump_buffer_ticks;
+
+        if (player->action == PLAYER_ACTION_GROUND || player->jump_coyote_timer > 0) {
+            jump(player);
+        }
+    }
+
+    if (input_is_action_pressed("player_jump")) {
+        if (player->action != PLAYER_ACTION_GROUND && player->jump_air_timer > 0) {
+            player->current_gravity_multiplier = player->jump_boosted_multiplier;
+            player->dy += player->jump_force_increase;
+        }
+    }
+}
+
+
+static void update_collider_x(Player *player) {
+    player->collider_x.w = player->rect.w;
+    player->collider_x.h = player->rect.h - 8;
+    player->collider_x.x = player->rect.x;
+    player->collider_x.y = player->rect.y + ((player->rect.h - player->collider_x.h) / 2);
+}
+
+
+static void update_collider_y(Player *player) {
+    player->collider_y.w = player->rect.w;
+    player->collider_y.h = player->rect.h;
+    player->collider_y.x = player->rect.x + ((player->rect.w - player->collider_y.w) / 2);
+    player->collider_y.y = player->rect.y;
+}
+
+
+static void apply_gravity(Player *player, float gravity) {
+    player->dy -= gravity * player->current_gravity_multiplier;
+    player->dy = fmax(player->dy, -player->terminal_velocity);
+
+    if (player->dy < 0) {
+        /* just started falling */
+        if (player->action == PLAYER_ACTION_GROUND) {
+            player->jump_coyote_timer = player->jump_coyote_ticks;
+        }
+
+        player->action = PLAYER_ACTION_FALL;
+    }
+}
+
+
+/* returns whether or not a correction was applied */
+static bool corner_correct(Player *player, Rect collision) {
+    /*
+     * somewhat of a hack here. we only want to do corner correction
+     * if the corner in question really is the corner of a "platform,"
+     * and not simply the edge of a single tile in a row of many
+     * tiles, as that would briefly clip the player into the ceiling,
+     * halting movement.  the dumbest way i could think of to fix this
+     * is to simply ensure that there's no tile to possibly clip into
+     * before correcting, by checking if there's a tile right above
+     * the center of the player
+     */
+    if (world_is_tile_at(player->world,
+                         player->rect.x + (player->rect.w / 2),
+                         player->rect.y - 1))
+    {
+        return false;
+    }
+
+    float player_center_x = player->collider_x.x + (player->collider_x.w / 2);
+    float collision_center_x = collision.x + (collision.w / 2); 
+    float abs_difference = fabs(player_center_x - collision_center_x);
+
+    /* we're good, no correction needed */
+    if (abs_difference < player->jump_corner_correction_offset)
+        return false;
+
+    /* collision was on player's right side */
+    if (player_center_x < collision_center_x) {
+        player->rect.x -= collision.w / 2;
+    }
+    /* collision was on player's left side */
+    else if (player_center_x > collision_center_x) {
+        player->rect.x += collision.w / 2;
+    }
+    
+    return true;
+}
+
+
+static void calc_collisions_x(Player *player) {
+    Rect collision;
+    bool is_colliding = world_find_intersect_frect(player->world, player->collider_x, &collision);
+    if (!is_colliding) return;
+
+    float player_center_x = player->collider_x.x + (player->collider_x.w / 2);
+    float collision_center_x = collision.x + (collision.w / 2); 
+
+    typedef enum CollisionDirection { COLLISION_LEFT = -1, COLLISION_RIGHT = 1 } CollisionDirection;
+    CollisionDirection dir_x =
+        player_center_x > collision_center_x ? COLLISION_LEFT : COLLISION_RIGHT;
+
+    player->rect.x -= collision.w * (float)dir_x;
+    player->dx = 0;
+}
+
+
+static void calc_collisions_y(Player *player) {
+    Rect collision;
+    bool is_colliding = world_find_intersect_frect(player->world, player->collider_y, &collision);
+    if (!is_colliding) return;
+
+    float player_center_y = player->collider_y.y + (player->collider_y.h / 2);
+    float collision_center_y = collision.y + (collision.h / 2); 
+
+    typedef enum CollisionDirection { COLLISION_ABOVE = -1, COLLISION_BELOW = 1 } CollisionDirection;
+    CollisionDirection dir_y =
+        player_center_y > collision_center_y ? COLLISION_ABOVE : COLLISION_BELOW;
+
+    /* before the resolution */
+    if (dir_y == COLLISION_ABOVE) {
+        if (corner_correct(player, collision)) {
+            return;
+        }
+    }
+
+    /* resolution */
+    player->rect.y -= collision.h * (float)dir_y;
+    player->dy = 0;
+
+    /* after the resolution */
+    if (dir_y == COLLISION_BELOW) {
+        /* bandaid fix for float precision-related jittering */
+        player->rect.y = ceilf(player->rect.y);
+
+        player->action = PLAYER_ACTION_GROUND;
+
+        if (player->jump_buffer_timer > 0) {
+            jump(player);
+            apply_gravity(player, player->world->gravity);
+        }
+    } else if (dir_y == COLLISION_ABOVE) {
+        player->jump_air_timer = 0;
+    }
+}
+
+
+Player *player_create(World *world) {
+    Player *player = cmalloc(sizeof *player);
+
+    *player = (Player) {
+        .world = world,
+
+        .sprite_w = 48,
+        .sprite_h = 48,
+
+        .rect = (Rect) {
+            .x = 92,
+            .y = 200,
+            .w = 16,
+            .h = 32,
+        },
+
+        .action = PLAYER_ACTION_GROUND,
+
+        .collider_thickness = 42,
+        .max_dx = 8,
+        .run_horizontal_speed = 0.5f,
+        .horizontal_damping = 0.9f,
+        .current_gravity_multiplier = 1,
+        .terminal_velocity = 30,
+
+        .jump_force_initial = 10,
+        .jump_force_increase = 1,
+        .jump_air_ticks = 18,
+        .jump_coyote_ticks = 8,
+        .jump_buffer_ticks = 8,
+
+        .jump_default_multiplier = 1.4f,
+        .jump_boosted_multiplier = 1,
+
+        .jump_corner_correction_offset = 16.0f,
+    };
+
+    return player;
+}
+
+
+static void drawdef(Player *player) {
+    m_sprite("/assets/player/baron-walk.png",
+            (Rect) {
+                .x = player->rect.x + ((player->rect.w - player->sprite_w) / 2),
+                .y = player->rect.y - 8,
+                .w = player->sprite_w,
+                .h = player->sprite_h,
+            });
+
+    draw_circle((Vec2) { 256, 128 },
+                24,
+                (Color) { 255, 0, 0, 255 });
+}
+
+
+static void drawdef_debug(Player *player) {
+    if (!ctx.debug)
+        return;
+
+    /* const int info_separation = 24; */
+    /* const struct RectPrimitive info_theme = { */
+    /*  .x = 8, */
+    /*  .r = 0, .g = 0, .b = 0, .a = 255, */
+    /* }; */
+
+    draw_rectangle(player->collider_x,
+                   (Color){ 0, 0, 255, 128 });
+
+    draw_rectangle(player->collider_y,
+                   (Color){ 0, 0, 255, 128 });
+}
+
+
+void player_destroy(Player *player) {
+    free(player);
+}
+
+
+void player_calc(Player *player) {
+    update_timers(player);
+
+    input_move(player);
+    input_jump(player);
+
+    player->rect.x += player->dx;
+    update_collider_x(player);
+    calc_collisions_x(player);
+
+    apply_gravity(player, player->world->gravity);
+    player->rect.y -= player->dy;
+    update_collider_y(player);
+    calc_collisions_y(player);
+
+    update_collider_x(player);
+    update_collider_y(player);
+
+    drawdef(player);
+    drawdef_debug(player);
+}

apps/demos/platformer/player.h

@@ -0,0 +1,65 @@
+#ifndef PLAYER_H
+#define PLAYER_H
+
+#include "twn_game_api.h"
+
+
+typedef struct World World;
+
+
+typedef enum PlayerAction {
+    PLAYER_ACTION_GROUND,
+    PLAYER_ACTION_FALL,
+    PLAYER_ACTION_JUMP,
+} PlayerAction;
+
+
+typedef struct Player {
+    World *world;
+
+    /* visual */
+    float sprite_w;
+    float sprite_h;
+
+    /* body */
+    Rect rect;
+
+    /* state */
+    PlayerAction action;
+
+    /* physics */
+    Rect collider_x;
+    Rect collider_y;
+    int collider_thickness;
+    float dx;
+    float dy;
+    float max_dx;
+    float run_horizontal_speed;
+    float horizontal_damping;
+    float current_gravity_multiplier;
+    float terminal_velocity;
+
+    /* jumping */
+    float jump_force_initial;
+    float jump_force_increase; /* aka "jump power", increment of dy per tick */
+    int jump_air_ticks;
+    int jump_air_timer;
+    int jump_coyote_ticks;
+    int jump_coyote_timer;
+    int jump_buffer_ticks;
+    int jump_buffer_timer;
+
+    /* gravity multipliers */
+    float jump_default_multiplier;
+    float jump_boosted_multiplier;
+
+    float jump_corner_correction_offset; /* from center */
+} Player;
+
+
+Player *player_create(World *world);
+void player_destroy(Player *player);
+void player_calc(Player *player);
+
+
+#endif

apps/demos/platformer/scenes/ingame.c

@@ -0,0 +1,60 @@
+#include "ingame.h"
+#include "title.h"
+#include "scene.h"
+
+#include "twn_game_api.h"
+#include "twn_vec.h"
+
+#include <SDL2/SDL.h>
+
+
+static void ingame_tick(State *state) {
+    SceneIngame *scn = (SceneIngame *)state->scene;
+
+    world_drawdef(scn->world);
+    player_calc(scn->player);
+
+    const Vec3 right = m_vec_norm(m_vec_cross(scn->cam.target, scn->cam.up));
+    const float speed = 0.04f; /* TODO: put this in a better place */
+    if (input_is_action_pressed("player_left"))
+        scn->cam.pos = vec3_sub(scn->cam.pos, m_vec_scale(right, speed));
+
+    if (input_is_action_pressed("player_right"))
+        scn->cam.pos = vec3_add(scn->cam.pos, m_vec_scale(right, speed));
+
+    if (input_is_action_pressed("player_forward"))
+        scn->cam.pos = vec3_add(scn->cam.pos, m_vec_scale(scn->cam.target, speed));
+
+    if (input_is_action_pressed("player_backward"))
+        scn->cam.pos = vec3_sub(scn->cam.pos, m_vec_scale(scn->cam.target, speed));
+
+    if (input_is_action_pressed("player_jump"))
+        scn->cam.pos.y += speed;
+
+    if (input_is_action_pressed("player_run"))
+        scn->cam.pos.y -= speed;
+}
+
+
+static void ingame_end(State *state) {
+    SceneIngame *scn = (SceneIngame *)state->scene;
+    player_destroy(scn->player);
+    world_destroy(scn->world);
+    free(state->scene);
+}
+
+
+Scene *ingame_scene(State *state) {
+    (void)state;
+
+    SceneIngame *new_scene = ccalloc(1, sizeof *new_scene);
+    new_scene->base.tick = ingame_tick;
+    new_scene->base.end = ingame_end;
+
+    new_scene->world = world_create();
+    new_scene->player = player_create(new_scene->world);
+
+    new_scene->cam = (Camera){ .pos = { 32, 0, 1 }, .up = { 0, 1, 0 }, .fov = (float)M_PI_2 };
+
+    return (Scene *)new_scene;
+}

apps/demos/platformer/scenes/ingame.h

@@ -0,0 +1,30 @@
+#ifndef INGAME_H
+#define INGAME_H
+
+#include "twn_game_api.h"
+
+#include "../state.h"
+#include "scene.h"
+#include "../player.h"
+#include "../world.h"
+
+
+typedef struct SceneIngame {
+    Scene base;
+
+    World *world;
+    Player *player;
+
+    Camera cam;
+
+    /* TODO: put this in a better place */
+    float yaw;
+    float pitch;
+    float roll;
+} SceneIngame;
+
+
+Scene *ingame_scene(State *state);
+
+
+#endif

apps/demos/platformer/scenes/scene.c

@@ -0,0 +1,8 @@
+#include "scene.h"
+#include "../state.h"
+
+
+void switch_to(State *state, Scene *(*scene_func)(State *)) {
+    state->next_scene = scene_func(state);
+    state->is_scene_switching = true;
+}

apps/demos/platformer/scenes/scene.h

@@ -0,0 +1,16 @@
+#ifndef SCENE_H
+#define SCENE_H
+
+
+typedef struct State State;
+typedef struct Scene {
+    char *id;
+    void (*tick)(State *);
+    void (*end)(State *);
+} Scene;
+
+
+void switch_to(State *state, Scene *(*scene_func)(State *));
+
+
+#endif

apps/demos/platformer/scenes/title.c

@@ -0,0 +1,75 @@
+#include "title.h"
+#include "ingame.h"
+#include "../world.h"
+#include "../player.h"
+
+#include "twn_game_api.h"
+
+#include <SDL2/SDL.h>
+
+#include <stdio.h>
+
+
+static void title_tick(State *state) {
+    SceneTitle *scn = (SceneTitle *)state->scene;
+    (void)scn;
+
+    if (input_is_action_just_pressed("ui_accept")) {
+        switch_to(state, ingame_scene);
+        return;
+    }
+
+
+    m_sprite("/assets/title.png", ((Rect) {
+            ((float)ctx.base_draw_w / 2) - ((float)320 / 2), 64, 320, 128 }));
+    
+    
+    /* draw the tick count as an example of dynamic text */
+    size_t text_str_len = snprintf(NULL, 0, "%lu", state->ctx->tick_count) + 1;
+    char *text_str = cmalloc(text_str_len);
+    snprintf(text_str, text_str_len, "%lu", state->ctx->tick_count);
+
+    const char *font = "fonts/kenney-pixel.ttf";
+    int text_h = 32;
+    int text_w = draw_text_width(text_str, text_h, font);
+
+    draw_rectangle(
+        (Rect) {
+            .x = 0,
+            .y = 0,
+            .w = (float)text_w,
+            .h = (float)text_h,
+        },
+        (Color) { 0, 0, 0, 255 }
+    );
+    draw_text(
+        text_str,
+        (Vec2){ 0, 0 },
+        text_h,
+        (Color) { 255, 255, 255, 255 },
+        font
+    );
+    free(text_str);
+}
+
+
+static void title_end(State *state) {
+    SceneTitle *scn = (SceneTitle *)state->scene;
+    player_destroy(scn->player);
+    world_destroy(scn->world);
+    free(state->scene);
+}
+
+
+Scene *title_scene(State *state) {
+    (void)state;
+
+    SceneTitle *new_scene = ccalloc(1, sizeof *new_scene);
+    new_scene->base.tick = title_tick;
+    new_scene->base.end = title_end;
+
+    new_scene->world = world_create();
+    new_scene->player = player_create(new_scene->world);
+
+    return (Scene *)new_scene;
+}

apps/demos/platformer/scenes/title.h

@@ -0,0 +1,21 @@
+#ifndef TITLE_H
+#define TITLE_H
+
+#include "../state.h"
+#include "scene.h"
+#include "../player.h"
+#include "../world.h"
+
+
+typedef struct SceneTitle {
+    Scene base;
+
+    World *world;
+    Player *player;
+} SceneTitle;
+
+
+Scene *title_scene(State *state);
+
+
+#endif

apps/demos/platformer/state.h

@@ -0,0 +1,20 @@
+#ifndef STATE_H
+#define STATE_H
+
+
+#include "twn_game_api.h"
+
+#include <stdbool.h>
+
+
+typedef struct Scene Scene;
+
+typedef struct State {
+    Context *ctx;
+    Scene *scene;
+    Scene *next_scene;
+    bool is_scene_switching;
+} State;
+
+
+#endif

apps/demos/platformer/world.c

@@ -0,0 +1,188 @@
+#include "twn_game_api.h"
+
+#include "world.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <tgmath.h>
+
+
+static void update_tiles(struct World *world) {
+    for (size_t row = 0; row < world->tilemap_height; ++row) {
+        for (size_t col = 0; col < world->tilemap_width; ++col) {
+            world->tiles[(row * world->tilemap_width) + col] = (struct Tile) {
+                .rect = (Recti) {
+                    .x = (int)col * world->tile_size,
+                    .y = (int)row * world->tile_size,
+                    .w = world->tile_size,
+                    .h = world->tile_size,
+                },
+                .type = world->tilemap[row][col],
+            };
+        }
+    }
+}
+
+
+static Vec2i to_grid_location(struct World *world, float x, float y) {
+    return (Vec2i) {
+        .x = (int)floor(x / (float)world->tile_size),
+        .y = (int)floor(y / (float)world->tile_size),
+    };
+}
+
+
+static void drawdef_debug(struct World *world) {
+    if (!ctx.debug) return;
+
+    for (size_t i = 0; i < world->tilemap_height * world->tilemap_width; ++i) {
+        if (world->tiles[i].type == TILE_TYPE_VOID) continue;
+
+        draw_rectangle(to_frect(world->tiles[i].rect),
+                        (Color) { 255, 0, 255, 128 });
+    }
+}
+
+
+struct World *world_create(void) {
+    struct World *world = cmalloc(sizeof *world);
+
+    *world = (struct World) {
+        .tiles = NULL,
+        .tile_size = 42,
+        .tilemap_width = 20,
+        .tilemap_height = 12,
+        .gravity = 1,
+    };
+
+    /* create the tilemap */
+    /* it simply stores what's in each tile as a 2d array */
+    /* on its own, it's entirely unrelated to drawing or logic */
+    world->tilemap = cmalloc(sizeof *world->tilemap * world->tilemap_height);
+    for (size_t i = 0; i < world->tilemap_height; ++i) {
+        world->tilemap[i] = cmalloc(sizeof **world->tilemap * world->tilemap_width);
+
+        for (size_t j = 0; j < world->tilemap_width; ++j) {
+            world->tilemap[i][j] = TILE_TYPE_VOID;
+        }
+    }
+
+    for (size_t i = 0; i < 12; ++i) {
+        world->tilemap[world->tilemap_height-2][2+i] = TILE_TYPE_SOLID;
+    }
+    world->tilemap[world->tilemap_height-3][8] = TILE_TYPE_SOLID;
+    world->tilemap[world->tilemap_height-4][8] = TILE_TYPE_SOLID;
+    world->tilemap[world->tilemap_height-5][10] = TILE_TYPE_SOLID;
+    world->tilemap[world->tilemap_height-6][10] = TILE_TYPE_SOLID;
+    for (size_t i = 0; i < 7; ++i) {
+        world->tilemap[world->tilemap_height-6][12+i] = TILE_TYPE_SOLID;
+    }
+
+    /* the tiles array contains data meant to be used by other logic */
+    /* most importantly, it is used to draw the tiles */
+    const size_t tile_count = world->tilemap_height * world->tilemap_width;
+    world->tiles = cmalloc(sizeof *world->tiles * tile_count);
+    update_tiles(world);
+
+    return world;
+}
+
+
+void world_destroy(struct World *world) {
+    free(world->tiles);
+
+    for (size_t i = 0; i < world->tilemap_height; ++i) {
+        free(world->tilemap[i]);
+    }
+    free(world->tilemap);
+
+    free(world);
+}
+
+
+void world_drawdef(struct World *world) {
+    for (size_t i = 0; i < world->tilemap_height * world->tilemap_width; ++i) {
+        if (world->tiles[i].type == TILE_TYPE_VOID)
+            continue;
+
+        m_sprite("/assets/white.png", to_frect(world->tiles[i].rect));
+    }
+
+    drawdef_debug(world);
+}
+
+
+bool world_find_intersect_frect(struct World *world, Rect rect, Rect *intersection) {
+    bool is_intersecting = false;
+
+    const size_t tile_count = world->tilemap_height * world->tilemap_width;
+    for (size_t i = 0; i < tile_count; ++i) {
+        if (world->tiles[i].type == TILE_TYPE_VOID)
+            continue;
+
+        Rect tile_frect = {
+            .x = (float)(world->tiles[i].rect.x),
+            .y = (float)(world->tiles[i].rect.y),
+            .w = (float)(world->tiles[i].rect.w),
+            .h = (float)(world->tiles[i].rect.h),
+        };
+
+        if (intersection == NULL) {
+            Rect temp;
+            is_intersecting = overlap_frect(&rect, &tile_frect, &temp);
+        } else {
+            is_intersecting = overlap_frect(&rect, &tile_frect, intersection);
+        }
+
+        if (is_intersecting)
+            break; 
+    }
+
+    return is_intersecting;
+}
+
+
+bool world_find_intersect_rect(struct World *world, Recti rect, Recti *intersection) {
+    bool is_intersecting = false;
+
+    const size_t tile_count = world->tilemap_height * world->tilemap_width;
+    for (size_t i = 0; i < tile_count; ++i) {
+        if (world->tiles[i].type == TILE_TYPE_VOID)
+            continue;
+
+        Recti *tile_rect = &world->tiles[i].rect;
+
+        if (intersection == NULL) {
+            Recti temp;
+            is_intersecting = overlap_rect(&rect, tile_rect, &temp);
+        } else {
+            is_intersecting = overlap_rect(&rect, tile_rect, intersection);
+        }
+
+        if (is_intersecting)
+            break;
+    }
+
+    return is_intersecting;
+}
+
+
+bool world_is_tile_at(struct World *world, float x, float y) {
+    Vec2i position_in_grid = to_grid_location(world, x, y);
+    return world->tilemap[position_in_grid.y][position_in_grid.x] != TILE_TYPE_VOID;
+}
+
+
+void world_place_tile(struct World *world, float x, float y) {
+    Vec2i position_in_grid = to_grid_location(world, x, y);
+    world->tilemap[position_in_grid.y][position_in_grid.x] = TILE_TYPE_SOLID;
+    update_tiles(world);
+}
+
+
+void world_remove_tile(struct World *world, float x, float y) {
+    Vec2i position_in_grid = to_grid_location(world, x, y);
+    world->tilemap[position_in_grid.y][position_in_grid.x] = TILE_TYPE_VOID;
+    update_tiles(world);
+}

apps/demos/platformer/world.h

@@ -0,0 +1,44 @@
+#ifndef WORLD_H
+#define WORLD_H
+
+#include "twn_game_api.h"
+
+#include <stdint.h>
+#include <stdbool.h>
+
+
+typedef enum TileType {
+    TILE_TYPE_VOID,
+    TILE_TYPE_SOLID,
+} TileType;
+
+
+typedef struct Tile {
+    Recti rect;
+    TileType type;
+} Tile;
+
+
+typedef struct World {
+    TileType **tilemap;
+    Tile *tiles;
+    
+    int tile_size;
+    unsigned int tilemap_width;
+    unsigned int tilemap_height;
+    size_t tile_nonvoid_count;
+    float gravity;
+} World;
+
+
+World *world_create(void);
+void world_destroy(World *world);
+void world_drawdef(World *world);
+bool world_find_intersect_frect(World *world, Rect rect, Rect *intersection);
+bool world_find_intersect_rect(World *world, Recti rect, Recti *intersection);
+bool world_is_tile_at(World *world, float x, float y);
+void world_place_tile(World *world, float x, float y);
+void world_remove_tile(World *world, float x, float y);
+
+
+#endif

apps/demos/scenery/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.21)
+
+project(scenery LANGUAGES C)
+
+if(NOT CMAKE_BUILD_TYPE)
+        set(CMAKE_BUILD_TYPE Debug)
+endif()
+
+add_subdirectory($ENV{TWNROOT} $ENV{TWNBUILDDIR})
+
+set(SOURCE_FILES
+        game.c
+        state.h
+
+        scenes/scene.c scenes/scene.h
+        scenes/title.c scenes/title.h
+        scenes/ingame.c scenes/ingame.h
+)
+
+use_townengine(${PROJECT_NAME} "${SOURCE_FILES}" ${CMAKE_CURRENT_SOURCE_DIR})

apps/demos/scenery/data/packs/data.toml

@@ -0,0 +1,3 @@
+[[deps]]
+source = "../../common-data" # where does it come from, might be an url
+name = "common-data"         # should be globally unique

apps/demos/scenery/data/twn.toml

@@ -0,0 +1,11 @@
+[about]
+title = "Serene Scenery"
+developer = "Townengine Team"
+app_id = "platformer-demo"
+dev_id = "townengine-team"
+
+[game]
+base_render_width = 640
+base_render_height = 360
+
+[engine]

apps/demos/scenery/game.c

@@ -0,0 +1,80 @@
+#include "state.h"
+#include "scenes/scene.h"
+#include "scenes/title.h"
+
+#include "twn_game_api.h"
+
+#include <stdio.h>
+#include <malloc.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+void game_tick(void) {
+    if (ctx.initialization_needed) {
+        if (!ctx.udata) {
+            ctx.udata = ccalloc(1, sizeof (State));
+
+            State *state = ctx.udata;
+            state->ctx = &ctx;
+            state->scene = title_scene(state);
+        }
+
+        input_add_action("debug_toggle");
+        input_bind_action_control("debug_toggle", CONTROL_BACKSPACE);
+
+        input_add_action("debug_dump_atlases");
+        input_bind_action_control("debug_dump_atlases", CONTROL_HOME);
+
+        input_add_action("player_left");
+        input_bind_action_control("player_left", CONTROL_A);
+
+        input_add_action("player_right");
+        input_bind_action_control("player_right", CONTROL_D);
+
+        input_add_action("player_forward");
+        input_bind_action_control("player_forward", CONTROL_W);
+
+        input_add_action("player_backward");
+        input_bind_action_control("player_backward", CONTROL_S);
+
+        input_add_action("player_jump");
+        input_bind_action_control("player_jump", CONTROL_SPACE);
+
+        input_add_action("player_run");
+        input_bind_action_control("player_run", CONTROL_LSHIFT);
+
+        input_add_action("ui_accept");
+        input_bind_action_control("ui_accept", CONTROL_RETURN);
+
+        input_add_action("mouse_capture_toggle");
+        input_bind_action_control("mouse_capture_toggle", CONTROL_ESCAPE);
+    }
+
+    State *state = ctx.udata;
+
+    if (input_is_action_just_pressed("debug_toggle")) {
+        ctx.debug = !ctx.debug;
+    }
+
+    if (input_is_action_just_pressed("debug_dump_atlases")) {
+        textures_dump_atlases();
+    }
+
+    state->scene->tick(state);
+
+    /* there's a scene switch pending, we can do it now that the tick is done */
+    if (state->next_scene != NULL) {
+        state->scene->end(state);
+        state->scene = state->next_scene;
+        state->is_scene_switching = false;
+        state->next_scene = NULL;
+    }
+}
+
+
+void game_end(void) {
+    State *state = ctx.udata;
+    state->scene->end(state);
+    free(state);
+}

apps/demos/scenery/scenes/ingame.c

@@ -0,0 +1,117 @@
+#include "ingame.h"
+#include "title.h"
+#include "scene.h"
+
+#include "twn_game_api.h"
+#include "twn_vec.h"
+
+#define STB_PERLIN_IMPLEMENTATION
+#include <stb_perlin.h>
+#include <SDL2/SDL.h>
+
+#include <stdlib.h>
+
+
+static void ingame_tick(State *state) {
+    SceneIngame *scn = (SceneIngame *)state->scene;
+
+    if (input_is_mouse_captured()) {
+        const float sensitivity = 0.6f; /* TODO: put this in a better place */
+        scn->yaw += (float)ctx.mouse_relative_position.x * sensitivity;
+        scn->pitch -= (float)ctx.mouse_relative_position.y * sensitivity;
+        scn->pitch = clampf(scn->pitch, -89.0f, 89.0f);
+
+        const float yaw_rad = scn->yaw * (float)DEG2RAD;
+        const float pitch_rad = scn->pitch * (float)DEG2RAD;
+
+        scn->cam.target = m_vec_norm(((Vec3){
+            cosf(yaw_rad) * cosf(pitch_rad),
+            sinf(pitch_rad),
+            sinf(yaw_rad) * cosf(pitch_rad)
+        }));
+    }
+
+    const Vec3 right = m_vec_norm(m_vec_cross(scn->cam.target, scn->cam.up));
+    const float speed = 0.04f; /* TODO: put this in a better place */
+    if (input_is_action_pressed("player_left"))
+        scn->cam.pos = vec3_sub(scn->cam.pos, m_vec_scale(right, speed));
+
+    if (input_is_action_pressed("player_right"))
+        scn->cam.pos = vec3_add(scn->cam.pos, m_vec_scale(right, speed));
+
+    if (input_is_action_pressed("player_forward"))
+        scn->cam.pos = vec3_add(scn->cam.pos, m_vec_scale(scn->cam.target, speed));
+
+    if (input_is_action_pressed("player_backward"))
+        scn->cam.pos = vec3_sub(scn->cam.pos, m_vec_scale(scn->cam.target, speed));
+
+    if (input_is_action_pressed("player_jump"))
+        scn->cam.pos.y += speed;
+
+    if (input_is_action_pressed("player_run"))
+        scn->cam.pos.y -= speed;
+
+    /* toggle mouse capture with end key */
+    if (input_is_action_just_pressed("mouse_capture_toggle")) {
+        input_set_mouse_captured(!input_is_mouse_captured());
+    }
+
+    draw_camera(&scn->cam);
+
+    #define TERRAIN_FREQUENCY 0.1f
+
+    for (int ly = 64; ly--;) {
+        for (int lx = 64; lx--;) {
+            float x = SDL_truncf(scn->cam.pos.x + 32 - lx);
+            float y = SDL_truncf(scn->cam.pos.z + 32 - ly);
+
+            float d0 = stb_perlin_noise3((float)x       * TERRAIN_FREQUENCY, (float)y       * TERRAIN_FREQUENCY, 0, 0, 0, 0) * 3 - 6;
+            float d1 = stb_perlin_noise3((float)(x + 1) * TERRAIN_FREQUENCY, (float)y       * TERRAIN_FREQUENCY, 0, 0, 0, 0) * 3 - 6;
+            float d2 = stb_perlin_noise3((float)(x + 1) * TERRAIN_FREQUENCY, (float)(y - 1) * TERRAIN_FREQUENCY, 0, 0, 0, 0) * 3 - 6;
+            float d3 = stb_perlin_noise3((float)x       * TERRAIN_FREQUENCY, (float)(y - 1) * TERRAIN_FREQUENCY, 0, 0, 0, 0) * 3 - 6;
+
+            draw_triangle("/assets/grass.png",
+                            (Vec3){ (float)x,     d0, (float)y },
+                            (Vec3){ (float)x + 1, d1, (float)y },
+                            (Vec3){ (float)x,     d3, (float)y - 1 },
+                            (Vec2){ 128, 128 },
+                            (Vec2){ 128, 0 },
+                            (Vec2){ 0, 128 });
+
+            draw_triangle("/assets/grass.png",
+                            (Vec3){ (float)x + 1, d1, (float)y },
+                            (Vec3){ (float)x + 1, d2, (float)y - 1 },
+                            (Vec3){ (float)x,     d3, (float)y - 1 },
+                            (Vec2){ 128, 0 },
+                            (Vec2){ 0, 0 },
+                            (Vec2){ 0, 128 });
+        }
+    }
+
+    draw_skybox("/assets/miramar/miramar_*.tga");
+    draw_fog(0.9, 1.0, 0.05, (Color){ 140, 147, 160, 255 });
+}
+
+
+static void ingame_end(State *state) {
+    free(state->scene);
+}
+
+
+Scene *ingame_scene(State *state) {
+    (void)state;
+
+    SceneIngame *new_scene = ccalloc(1, sizeof *new_scene);
+    new_scene->base.tick = ingame_tick;
+    new_scene->base.end = ingame_end;
+
+    new_scene->cam = (Camera){ .pos = { 32, 0, 1 }, .up = { 0, 1, 0 }, .fov = (float)M_PI_2 };
+
+    m_audio(m_set(path, "music/mod65.xm"),
+            m_opt(channel, "soundtrack"),
+            m_opt(repeat, true));
+
+    input_set_mouse_captured(true);
+
+    return (Scene *)new_scene;
+}

apps/demos/scenery/scenes/ingame.h

@@ -0,0 +1,25 @@
+#ifndef INGAME_H
+#define INGAME_H
+
+#include "twn_game_api.h"
+
+#include "../state.h"
+#include "scene.h"
+
+
+typedef struct SceneIngame {
+    Scene base;
+
+    Camera cam;
+
+    /* TODO: put this in a better place */
+    float yaw;
+    float pitch;
+    float roll;
+} SceneIngame;
+
+
+Scene *ingame_scene(State *state);
+
+
+#endif

apps/demos/scenery/scenes/scene.c

@@ -0,0 +1,8 @@
+#include "scene.h"
+#include "../state.h"
+
+
+void switch_to(State *state, Scene *(*scene_func)(State *)) {
+    state->next_scene = scene_func(state);
+    state->is_scene_switching = true;
+}

apps/demos/scenery/scenes/scene.h

@@ -0,0 +1,16 @@
+#ifndef SCENE_H
+#define SCENE_H
+
+
+typedef struct State State;
+typedef struct Scene {
+    char *id;
+    void (*tick)(State *);
+    void (*end)(State *);
+} Scene;
+
+
+void switch_to(State *state, Scene *(*scene_func)(State *));
+
+
+#endif

apps/demos/scenery/scenes/title.c

@@ -0,0 +1,61 @@
+#include "title.h"
+#include "ingame.h"
+
+#include "twn_game_api.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+static void title_tick(State *state) {
+    SceneTitle *scn = (SceneTitle *)state->scene;
+    (void)scn;
+
+    if (input_is_action_just_pressed("ui_accept")) {
+        switch_to(state, ingame_scene);
+        return;
+    }
+
+
+    m_sprite("/assets/title.png", ((Rect) {
+            ((float)ctx.base_draw_w / 2) - ((float)320 / 2), 64, 320, 128 }));
+    
+    
+    /* draw the tick count as an example of dynamic text */
+    size_t text_str_len = snprintf(NULL, 0, "%lu", state->ctx->tick_count) + 1;
+    char *text_str = cmalloc(text_str_len);
+    snprintf(text_str, text_str_len, "%lu", state->ctx->tick_count);
+
+    const char *font = "/fonts/kenney-pixel.ttf";
+    int text_h = 32;
+    int text_w = draw_text_width(text_str, text_h, font);
+
+    draw_rectangle(
+        (Rect) {
+            .x = 0,
+            .y = 0,
+            .w = (float)text_w,
+            .h = (float)text_h,
+        },
+        (Color) { 0, 0, 0, 255 }
+    );
+    draw_text(text_str, (Vec2){ 0, 0 }, text_h, (Color) { 255, 255, 255, 255 }, font);
+
+    free(text_str);
+}
+
+
+static void title_end(State *state) {
+    free(state->scene);
+}
+
+
+Scene *title_scene(State *state) {
+    (void)state;
+
+    SceneTitle *new_scene = ccalloc(1, sizeof *new_scene);
+    new_scene->base.tick = title_tick;
+    new_scene->base.end = title_end;
+
+    return (Scene *)new_scene;
+}

apps/demos/scenery/scenes/title.h

@@ -0,0 +1,16 @@
+#ifndef TITLE_H
+#define TITLE_H
+
+#include "../state.h"
+#include "scene.h"
+
+
+typedef struct SceneTitle {
+    Scene base;
+} SceneTitle;
+
+
+Scene *title_scene(State *state);
+
+
+#endif

apps/demos/scenery/state.h

@@ -0,0 +1,20 @@
+#ifndef STATE_H
+#define STATE_H
+
+
+#include "twn_game_api.h"
+
+#include <stdbool.h>
+
+
+typedef struct Scene Scene;
+
+typedef struct State {
+    Context *ctx;
+    Scene *scene;
+    Scene *next_scene;
+    bool is_scene_switching;
+} State;
+
+
+#endif