Add instrument selection screen.

src/main.cpp

@@ -1,4 +1,5 @@
 #include "samples/ghhb_game.h"
+#include "samples/instrument_select.h"
 #include "samples/title_screen.h"
 #include "entities/song.h"
 
@@ -7,6 +8,8 @@
 #include <emscripten/emscripten.h>
 #endif
 
+int INSTRUMENT_GAMEPAD_INDEX[MAX_INSTRUMENT_TYPES] = {-1, -1, -1, -1};
+
 Game game;
 
 void update()
@@ -30,6 +33,7 @@ int main(int argc, char** argv)
     font_manager->set_texture_filter("Roboto", TEXTURE_FILTER_BILINEAR);
 
     game.add_scene<TitleScreen>("title");
+    game.add_scene<InstrumentSelectScreen>("instrument_select");
     game.add_scene<GHHBScene>("ghhb");
 
     Song& song = song_manager->load_song("mary_had_a_lil_lamb", "assets/songs/json/mary.json");

src/samples/ghhb_game.h

@@ -158,6 +158,8 @@ std::vector<Glyph> load_chart(const char* path)
 const char* const GHHB_CHART_PATH = "assets/songs/json/mary.json";
 } // namespace
 
+extern int INSTRUMENT_GAMEPAD_INDEX[MAX_INSTRUMENT_TYPES];
+
 class GHHBScene : public Scene
 {
 public:

src/samples/instrument_select.h

@@ -0,0 +1,193 @@
+#pragma once
+
+#include "engine/prefabs/includes.h"
+#include "ghhb_game.h"
+#include <array>
+#include <vector>
+
+class InstrumentSelectScreen : public Scene
+{
+public:
+    Font font = {0};
+
+    static constexpr int SLOT_TOP = 0;
+    static constexpr int SLOT_BOTTOM = 1;
+    static constexpr int SLOT_LEFT = 2;
+    static constexpr int SLOT_RIGHT = 3;
+
+    static constexpr int BUTTON_SLOT[4] = {
+        SLOT_TOP,   // GAMEPAD_BUTTON_LEFT_FACE_UP
+        SLOT_BOTTOM, // GAMEPAD_BUTTON_LEFT_FACE_DOWN
+        SLOT_LEFT,   // GAMEPAD_BUTTON_LEFT_FACE_LEFT
+        SLOT_RIGHT,  // GAMEPAD_BUTTON_LEFT_FACE_RIGHT
+    };
+    static constexpr int FACE_BUTTONS[4] = {
+        GAMEPAD_BUTTON_LEFT_FACE_UP,
+        GAMEPAD_BUTTON_LEFT_FACE_DOWN,
+        GAMEPAD_BUTTON_LEFT_FACE_LEFT,
+        GAMEPAD_BUTTON_LEFT_FACE_RIGHT,
+    };
+
+    static const Color BORDER_COLOR;
+    static const Color SECTION_BG_COLOR;
+
+    static constexpr const char* INSTRUMENT_IMAGE_PATHS[MAX_INSTRUMENT_TYPES] = {
+        "assets/instrument_0.png",
+        "assets/instrument_1.png",
+        "assets/instrument_2.png",
+        "assets/instrument_3.png",
+    };
+
+    std::array<int, MAX_INSTRUMENT_TYPES> instrument_owner = {-1, -1, -1, -1};
+    std::vector<int> participant_order;
+
+    void init_services() override { add_service<TextureService>(); }
+
+    void init() override
+    {
+        auto font_manager = game->get_manager<FontManager>();
+        font = font_manager->get_font("Roboto");
+        instrument_owner.fill(-1);
+        participant_order.clear();
+    }
+
+    int get_or_assign_gamepad_index(int physical_gamepad_id)
+    {
+        for (size_t i = 0; i < participant_order.size(); i++)
+        {
+            if (participant_order[i] == physical_gamepad_id)
+                return static_cast<int>(i);
+        }
+        if (participant_order.size() < static_cast<size_t>(MAX_INSTRUMENT_TYPES))
+        {
+            participant_order.push_back(physical_gamepad_id);
+            return static_cast<int>(participant_order.size() - 1);
+        }
+        return -1;
+    }
+
+    void update(float delta_time) override
+    {
+        for (int gp = 0; gp < MAX_GAMEPADS; gp++)
+        {
+            if (!IsGamepadAvailable(gp))
+                continue;
+            for (int b = 0; b < 4; b++)
+            {
+                if (IsGamepadButtonPressed(gp, FACE_BUTTONS[b]))
+                {
+                    int slot = BUTTON_SLOT[b];
+                    int gi = get_or_assign_gamepad_index(gp);
+                    if (gi >= 0)
+                        instrument_owner[slot] = gi;
+                }
+            }
+        }
+
+        bool all_selected = true;
+        for (int s = 0; s < MAX_INSTRUMENT_TYPES; s++)
+        {
+            if (instrument_owner[s] < 0)
+            {
+                all_selected = false;
+                break;
+            }
+        }
+        if (all_selected)
+        {
+            if (IsKeyPressed(KEY_ENTER))
+            {
+                for (int i = 0; i < MAX_INSTRUMENT_TYPES; i++)
+                    INSTRUMENT_GAMEPAD_INDEX[i] = instrument_owner[i];
+                game->go_to_scene("ghhb");
+                return;
+            }
+            for (int gp = 0; gp < MAX_GAMEPADS; gp++)
+            {
+                if (IsGamepadAvailable(gp) && IsGamepadButtonPressed(gp, GAMEPAD_BUTTON_MIDDLE_RIGHT))
+                {
+                    for (int i = 0; i < MAX_INSTRUMENT_TYPES; i++)
+                        INSTRUMENT_GAMEPAD_INDEX[i] = instrument_owner[i];
+                    game->go_to_scene("ghhb");
+                    return;
+                }
+            }
+        }
+    }
+
+    void draw() override
+    {
+        float w = static_cast<float>(GetScreenWidth());
+        float h = static_cast<float>(GetScreenHeight());
+        float cx = w * 0.5f;
+        float cy = h * 0.5f;
+
+        /* Vertices in counter-clockwise order so Raylib fills the triangle. */
+        Vector2 top_tri[3] = {{cx, cy}, {w, 0}, {0, 0}};
+        Vector2 bottom_tri[3] = {{0, h}, {w, h}, {cx, cy}};
+        Vector2 left_tri[3] = {{0, 0}, {0, h}, {cx, cy}};
+        Vector2 right_tri[3] = {{cx, cy}, {w, h}, {w, 0}};
+
+        auto draw_wedge = [this](const Vector2* v, int slot) {
+            Color fill = (instrument_owner[slot] >= 0) ? INSTRUMENT_COLORS[instrument_owner[slot]]
+                                                       : SECTION_BG_COLOR;
+            DrawTriangle(v[0], v[1], v[2], fill);
+        };
+
+        draw_wedge(top_tri, SLOT_TOP);
+        draw_wedge(bottom_tri, SLOT_BOTTOM);
+        draw_wedge(left_tri, SLOT_LEFT);
+        draw_wedge(right_tri, SLOT_RIGHT);
+
+        DrawLineEx(Vector2{0, 0}, Vector2{w, h}, 3.0f, BORDER_COLOR);
+        DrawLineEx(Vector2{w, 0}, Vector2{0, h}, 3.0f, BORDER_COLOR);
+
+        auto* tex_svc = get_service<TextureService>();
+        auto draw_center_icon = [this, tex_svc](float ix, float iy, int slot) {
+            const char* path = INSTRUMENT_IMAGE_PATHS[slot];
+            if (FileExists(path))
+            {
+                Texture2D& tex = tex_svc->get_texture(path);
+                float tw = static_cast<float>(tex.width);
+                float th = static_cast<float>(tex.height);
+                float scale = 1.0f;
+                float max_dim = 120.0f;
+                if (tw > max_dim || th > max_dim)
+                    scale = max_dim / (tw > th ? tw : th);
+                float dw = tw * scale;
+                float dh = th * scale;
+                DrawTextureEx(tex, Vector2{ix - dw * 0.5f, iy - dh * 0.5f}, 0.0f, scale, WHITE);
+            }
+            else
+            {
+                DrawRectangle(static_cast<int>(ix - 40), static_cast<int>(iy - 40), 80, 80,
+                              Color{80, 80, 100, 255});
+            }
+        };
+
+        draw_center_icon(cx, h / 6.0f, SLOT_TOP);
+        draw_center_icon(cx, h * 5.0f / 6.0f, SLOT_BOTTOM);
+        draw_center_icon(w / 6.0f, cy, SLOT_LEFT);
+        draw_center_icon(w * 5.0f / 6.0f, cy, SLOT_RIGHT);
+
+        bool all_selected = true;
+        for (int s = 0; s < MAX_INSTRUMENT_TYPES; s++)
+        {
+            if (instrument_owner[s] < 0)
+            {
+                all_selected = false;
+                break;
+            }
+        }
+        if (all_selected)
+        {
+            const char* prompt = "Press Start to begin";
+            float font_size = 24.0f;
+            float pw = MeasureTextEx(font, prompt, font_size, 1.0f).x;
+            DrawTextEx(font, prompt, Vector2{cx - pw * 0.5f, h - 40.0f}, font_size, 1.0f, WHITE);
+        }
+    }
+};
+
+inline const Color InstrumentSelectScreen::BORDER_COLOR = {45, 55, 72, 255};
+inline const Color InstrumentSelectScreen::SECTION_BG_COLOR = {95, 115, 140, 255};

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("ghhb");
+            game->go_to_scene("instrument_select");
         }
     }