Added song selection.

assets/songs/json/mary.json

@@ -2,7 +2,8 @@
   "header": {
     "keySignatures": [],
     "meta": [],
-    "name": "",
+    "name": "Mary Had A Little Lamb",
+    "artist": "Mrs Mary",
     "ppq": 480,
     "tempos": [
       {

src/entities/song.h

@@ -28,6 +28,7 @@ struct Track {
 
 struct Header {
     std::string name;
+    std::string artist;
     int ppq;
     float bpm;
 };
@@ -45,7 +46,8 @@ Song parseSong(const rapidjson::Document& doc) {
     if (doc.HasMember("header") && doc["header"].IsObject()) {
         const auto& h = doc["header"].GetObject();
         Header header;
-        header.name = h["name"].GetString();
+        header.name = h.HasMember("name") && h["name"].IsString() ? h["name"].GetString() : "";
+        header.artist = h.HasMember("artist") && h["artist"].IsString() ? h["artist"].GetString() : "";
         header.ppq = h["ppq"].GetInt();
         printf("header has tempos: %d\n", h.HasMember("tempos"));
         if (h.HasMember("tempos") && h["tempos"].IsArray()) {

src/main.cpp

@@ -1,5 +1,6 @@
 #include "samples/ghhb_game.h"
 #include "samples/instrument_select.h"
+#include "samples/song_select.h"
 #include "samples/title_screen.h"
 #include "entities/song.h"
 
@@ -10,6 +11,7 @@
 
 int INSTRUMENT_GAMEPAD_INDEX[MAX_INSTRUMENT_TYPES] = {-1, -1, -1, -1};
 int INSTRUMENT_PHYSICAL_GAMEPAD[MAX_INSTRUMENT_TYPES] = {-1, -1, -1, -1};
+std::string SELECTED_SONG_PATH = "assets/songs/json/mary.json";
 
 Game game;
 
@@ -34,6 +36,7 @@ int main(int argc, char** argv)
     font_manager->set_texture_filter("Roboto", TEXTURE_FILTER_BILINEAR);
 
     game.add_scene<TitleScreen>("title");
+    game.add_scene<SongSelectScreen>("song_select");
     game.add_scene<InstrumentSelectScreen>("instrument_select");
     game.add_scene<GHHBScene>("ghhb");
 

src/samples/ghhb_game.h

@@ -6,6 +6,7 @@
 #include "background.h"
 #include <algorithm>
 #include <cstdio>
+#include <string>
 #include <unordered_set>
 #include <vector>
 
@@ -154,10 +155,9 @@ std::vector<Glyph> load_chart(const char* path)
     return empty;
 }
 
-// const char* const GHHB_CHART_PATH = "assets/songs/json/tetris.json";
-const char* const GHHB_CHART_PATH = "assets/songs/json/mary.json";
 } // namespace
 
+extern std::string SELECTED_SONG_PATH;
 extern int INSTRUMENT_GAMEPAD_INDEX[MAX_INSTRUMENT_TYPES];
 extern int INSTRUMENT_PHYSICAL_GAMEPAD[MAX_INSTRUMENT_TYPES];
 
@@ -192,6 +192,14 @@ public:
 
     void on_enter() override
     {
+        chart = load_chart(SELECTED_SONG_PATH.c_str());
+        float first_note_time = 0.0f;
+        if (!chart.empty())
+        {
+            first_note_time = chart.front().time;
+            float lead_seconds = (hit_line_y - 60.0f) / SCROLL_PX_PER_SEC;
+            chart_time_offset = lead_seconds + LEAD_OFFSET_SECONDS - first_note_time;
+        }
         song_time = 0.0f;
         score = 0;
         combo = 0;
@@ -263,14 +271,6 @@ public:
                 }
             }
         }
-        chart = load_chart(GHHB_CHART_PATH);
-        float first_note_time = 0.0f;
-        if (!chart.empty())
-        {
-            first_note_time = chart.front().time;
-            float lead_seconds = (hit_line_y - 60.0f) / SCROLL_PX_PER_SEC;
-            chart_time_offset = lead_seconds + LEAD_OFFSET_SECONDS - first_note_time;
-        }
         background = add_game_object<Background>();
         background->add_tag("background");
     }

src/samples/instrument_select.h

@@ -79,10 +79,15 @@ public:
                     int slot = BUTTON_SLOT[b];
                     int gi = get_or_assign_gamepad_index(gp);
                     if (gi >= 0)
+                    {
+                        if (instrument_owner[slot] == gi)
+                            instrument_owner[slot] = -1;
+                        else
                             instrument_owner[slot] = gi;
                     }
                 }
             }
+        }
 
         bool all_selected = true;
         for (int s = 0; s < MAX_INSTRUMENT_TYPES; s++)

src/samples/song_select.h

@@ -0,0 +1,187 @@
+#pragma once
+
+#include "engine/prefabs/includes.h"
+#include "entities/song.h"
+#include "rapidjson/filereadstream.h"
+#include <cstdio>
+#include <vector>
+
+extern std::string SELECTED_SONG_PATH;
+
+struct SongEntry
+{
+    std::string name;
+    std::string artist;
+    std::string path;
+};
+
+inline std::vector<SongEntry> build_song_list(const std::vector<std::string>& paths)
+{
+    std::vector<SongEntry> entries;
+    for (const std::string& path : paths)
+    {
+        std::FILE* fp = std::fopen(path.c_str(), "rb");
+        if (!fp)
+            continue;
+        char read_buf[65536];
+        rapidjson::FileReadStream is(fp, read_buf, sizeof(read_buf));
+        rapidjson::Document doc;
+        if (doc.ParseStream(is).HasParseError())
+        {
+            std::fclose(fp);
+            continue;
+        }
+        std::fclose(fp);
+        Song song = parseSong(doc);
+        entries.push_back(
+            {song.header.name.empty() ? path : song.header.name, song.header.artist, path});
+    }
+    while (entries.size() < 4)
+    {
+        for (size_t i = 0; i < entries.size() && entries.size() < 4; i++)
+            entries.push_back(entries[i]);
+    }
+    return entries;
+}
+
+class SongSelectScreen : public Scene
+{
+public:
+    static constexpr int VISIBLE_SLOTS = 4;
+
+    Font font = {0};
+    std::vector<SongEntry> songs;
+    int selected_index = 0;
+    int scroll_offset = 0;
+
+    void init() override
+    {
+        auto font_manager = game->get_manager<FontManager>();
+        font = font_manager->get_font("Roboto");
+        std::vector<std::string> paths = {"assets/songs/json/mary.json"};
+        songs = build_song_list(paths);
+        selected_index = 0;
+        scroll_offset = 0;
+    }
+
+    void update(float delta_time) override
+    {
+        bool up = IsKeyPressed(KEY_UP);
+        bool down = IsKeyPressed(KEY_DOWN);
+        for (int gp = 0; gp < 4; gp++)
+        {
+            if (IsGamepadAvailable(gp))
+            {
+                if (IsGamepadButtonPressed(gp, GAMEPAD_BUTTON_LEFT_FACE_UP))
+                    up = true;
+                if (IsGamepadButtonPressed(gp, GAMEPAD_BUTTON_LEFT_FACE_DOWN))
+                    down = true;
+            }
+        }
+        int n = static_cast<int>(songs.size());
+        if (up)
+        {
+            if (selected_index > 0)
+                selected_index--;
+            else if (scroll_offset > 0)
+                scroll_offset--;
+            else
+            {
+                scroll_offset = n > VISIBLE_SLOTS ? n - VISIBLE_SLOTS : 0;
+                selected_index = n > VISIBLE_SLOTS ? VISIBLE_SLOTS - 1 : n - 1;
+            }
+        }
+        if (down)
+        {
+            if (selected_index < VISIBLE_SLOTS - 1 && scroll_offset + selected_index < n - 1)
+                selected_index++;
+            else if (scroll_offset + VISIBLE_SLOTS < n)
+                scroll_offset++;
+            else
+            {
+                scroll_offset = 0;
+                selected_index = 0;
+            }
+        }
+
+        bool confirm = IsKeyPressed(KEY_ENTER);
+        for (int gp = 0; gp < 4; gp++)
+        {
+            if (IsGamepadAvailable(gp) && IsGamepadButtonPressed(gp, GAMEPAD_BUTTON_MIDDLE_RIGHT))
+                confirm = true;
+        }
+        if (confirm && !songs.empty())
+        {
+            int idx = scroll_offset + selected_index;
+            if (idx >= 0 && idx < static_cast<int>(songs.size()))
+            {
+                SELECTED_SONG_PATH = songs[idx].path;
+                game->go_to_scene("instrument_select");
+            }
+        }
+    }
+
+    void draw() override
+    {
+        float w = static_cast<float>(GetScreenWidth());
+        float h = static_cast<float>(GetScreenHeight());
+
+        ClearBackground(SKYBLUE);
+
+        const char* title_text = "Select Song";
+        float title_size = 48.0f;
+        float title_w = MeasureTextEx(font, title_text, title_size, 1.0f).x;
+        DrawTextEx(font, title_text, Vector2{(w - title_w) * 0.5f, 60.0f}, title_size, 1.0f, WHITE);
+
+        float row_height = 80.0f;
+        float start_y = 180.0f;
+        float list_center_x = w * 0.5f;
+        float name_size = 28.0f;
+        float artist_size = 18.0f;
+        float artist_offset_x = 0.0f;
+        Color highlight_bg = {60, 80, 120, 220};
+        Color highlight_border = {100, 130, 180, 255};
+        float content_height = name_size + 4.0f + artist_size;
+        float box_pad_v = 6.0f;
+        float highlight_height = content_height + box_pad_v * 2.0f;
+
+        for (int i = 0; i < VISIBLE_SLOTS; i++)
+        {
+            int list_idx = scroll_offset + i;
+            float y = start_y + i * row_height;
+            bool selected = (i == selected_index);
+
+            if (list_idx < static_cast<int>(songs.size()))
+            {
+                const SongEntry& e = songs[list_idx];
+                if (selected)
+                {
+                    float box_w = w * 0.45f;
+                    float box_x = (w - box_w) * 0.5f;
+                    float box_y = y - box_pad_v;
+                    DrawRectangleRounded(
+                        Rectangle{box_x, box_y, box_w, highlight_height}, 0.2f, 12, highlight_bg);
+                    DrawRectangleRoundedLines(
+                        Rectangle{box_x, box_y, box_w, highlight_height}, 0.2f, 12,
+                        highlight_border);
+                }
+                float name_w = MeasureTextEx(font, e.name.c_str(), name_size, 1.0f).x;
+                DrawTextEx(font, e.name.c_str(),
+                          Vector2{list_center_x - name_w * 0.5f, y}, name_size, 1.0f, WHITE);
+                if (!e.artist.empty())
+                {
+                    float artist_w = MeasureTextEx(font, e.artist.c_str(), artist_size, 1.0f).x;
+                    DrawTextEx(font, e.artist.c_str(),
+                              Vector2{list_center_x - artist_w * 0.5f + artist_offset_x,
+                                      y + name_size + 4.0f},
+                              artist_size, 1.0f, Color{200, 200, 200, 255});
+                }
+            }
+        }
+
+        const char* hint = "D-Pad Up/Down  |  Start to confirm";
+        float hint_size = 20.0f;
+        float hint_w = MeasureTextEx(font, hint, hint_size, 1.0f).x;
+        DrawTextEx(font, hint, Vector2{(w - hint_w) * 0.5f, h - 50.0f}, hint_size, 1.0f, WHITE);
+    }
+};

src/samples/title_screen.h

@@ -18,7 +18,7 @@ public:
         // Trigger scene change on Enter key or gamepad start button.
         if (IsKeyPressed(KEY_ENTER) || IsGamepadButtonPressed(0, GAMEPAD_BUTTON_MIDDLE_RIGHT))
         {
-            game->go_to_scene("instrument_select");
+            game->go_to_scene("song_select");
         }
     }