2 files changed, 402 insertions, 0 deletions
diff --git a/src/games/minesweeper/Minesweeper.cpp b/src/games/minesweeper/Minesweeper.cpp
new file mode 100644
index 0000000..60502c6
--- /dev/null
+++ b/src/games/minesweeper/Minesweeper.cpp
@@ -0,0 +1,321 @@
+#include <renderer/RenderGroup.hpp>
+#include <games/minesweeper/Minesweeper.hpp>
+
+#include <algorithm>
+#include <random>
+
+// Todo: draw a difficulty selection menu at top-mid.
+
+// Note: How many mines?
+// - Beginner: 8x8 or 9x9 grid with 10 mines.
+// - Intermediate: 16x16 grid with 40 mines.
+// - Expert: 30x16 grid with 99 mines.
+
+Minesweeper::Minesweeper()
+{
+    float map_width = static_cast<float>(m_MapWidth);
+    float map_height = static_cast<float>(m_MapHeight);
+    float cell_size = 0.8f * std::min(m_WorldHeight / MAX_MAP_HEIGHT, m_WorldWidth / MAX_MAP_WIDTH);
+    float cell_size_without_border = 0.8f * cell_size;
+
+    m_MapViewPos = {
+        0.1f * cell_size_without_border + (m_WorldWidth - cell_size * map_width) / 2,
+        0.1f * cell_size_without_border + (m_WorldHeight - cell_size * map_height) / 2
+    };
+    m_CellOuterViewSize = {cell_size, cell_size};
+    m_CellInnerViewSize = {cell_size_without_border, cell_size_without_border};
+
+
+    // Todo: assert various stuff
+
+    Reinit();
+}
+
+void Minesweeper::Reinit() {
+    int32_t mine_count = 40;
+    memset(m_IsCoveredBitmap, 0xff, sizeof(m_IsCoveredBitmap));
+    memset(m_IsFlaggedBitmap, 0 , sizeof(m_IsFlaggedBitmap));
+    InitIsMineBitmap(mine_count);
+    InitAdjacentMineCounters();
+}
+
+void Minesweeper::InitIsMineBitmap(int32_t mine_count) {
+    assert(mine_count < m_MapWidth * m_MapHeight);
+
+    memset(m_IsMineBitmap, 0 , sizeof(m_IsMineBitmap));
+
+    std::mt19937 rng((std::random_device()()));
+    std::uniform_int_distribution<int32_t> dist(0, m_MapWidth * m_MapHeight - 1);
+
+    while (mine_count) {
+        int32_t random_pos = dist(rng);
+        int32_t x = random_pos / m_MapWidth;
+        int32_t y = random_pos % m_MapWidth;
+        if (!IsMine(x, y)) {
+            m_IsMineBitmap[y] |= 1 << x;
+            mine_count--;
+        }
+    }
+}
+
+void Minesweeper::InitAdjacentMineCounters() {
+    for (int32_t y = 0; y < m_MapHeight; y++) {
+        int32_t y0 = y > 0 ? y-1 : y;
+        int32_t y1 = y < m_MapHeight-1 ? y+1 : y;
+
+        for (int32_t x = 0; x < m_MapHeight; x++) {
+            int32_t x0 = x > 0 ? x-1 : x;
+            int32_t x1 = x < m_MapWidth-1 ? x+1 : x;
+
+            int32_t adjacent_mine_counter = 0;
+            for (int32_t inner_y = y0; inner_y <= y1; inner_y++) {
+                for (int32_t inner_x = x0; inner_x <= x1; inner_x++) {
+                    if (IsMine(inner_x, inner_y)) {
+                        adjacent_mine_counter++;
+                    }
+                }
+            }
+            if (IsMine(x, y)) {
+                adjacent_mine_counter = -1;
+            }
+
+            m_AdjacentMineCounters[y * m_MapWidth + x] = adjacent_mine_counter;
+        }
+    }
+}
+
+bool Minesweeper::Update(std::vector<SDL_Event> &events, RenderGroup &render_group) {
+    V3F32 clear_color = {0.3f, 0.2f, 0.3f};
+    render_group.SetCameraSize(4.0f, 3.0f);
+    render_group.Clear(clear_color);
+
+    if (m_RunState == MinesweeperRunState::Restart) {
+        Reinit();
+        m_RunState = MinesweeperRunState::Resume;
+    }
+
+    for (SDL_Event &event : events) {
+        if (m_RunState == MinesweeperRunState::Exit) {
+            return false;
+        }
+        else if (m_RunState == MinesweeperRunState::Pause) {
+            ProcessEventDuringPause(event, render_group);
+        }
+        else if (m_RunState == MinesweeperRunState::Resume) {
+            ProcessEventDuringResume(event, render_group);
+        }
+    }
+
+    if (m_RunState == MinesweeperRunState::Pause) {
+        DrawPauseMenu(render_group);
+    }
+    else if (m_RunState == MinesweeperRunState::GameOver) {
+        DrawGameOverMenu(render_group);
+    }
+
+    DrawBoard(render_group);
+
+    bool keep_running = m_RunState != MinesweeperRunState::Exit;
+    return keep_running;
+}
+
+void Minesweeper::ProcessEventDuringPause(SDL_Event &event, RenderGroup &render_group) {
+    switch (event.type) {
+    case SDL_EVENT_KEY_DOWN: {
+        if (event.key.key == SDLK_ESCAPE) {
+            m_RunState = MinesweeperRunState::Resume;
+        }
+    } break;
+    default:;
+    }
+}
+
+void Minesweeper::ProcessEventDuringResume(SDL_Event &event, RenderGroup &render_group) {
+    switch (event.type) {
+    case SDL_EVENT_KEY_DOWN: {
+        if (event.key.key == SDLK_ESCAPE) {
+            m_RunState = MinesweeperRunState::Pause;
+        }
+    } break;
+
+        case SDL_EVENT_MOUSE_BUTTON_DOWN: {
+            V2F32 click_screen_pos = {event.button.x, (float)render_group.m_ScreenHeight -1 - event.button.y};
+            V2F32 click_view_pos = ScreenPosToViewPos(click_screen_pos, render_group);
+
+        float x_adjusted = click_view_pos.x - m_MapViewPos.x;
+        float y_adjusted = click_view_pos.y - m_MapViewPos.y;
+        if (x_adjusted < 0.0f) {
+            break;
+        }
+        if (y_adjusted < 0.0f) {
+            break;
+        }
+
+        int32_t x = (int32_t)(x_adjusted / m_CellOuterViewSize.x);
+        int32_t y = (int32_t)(y_adjusted / m_CellOuterViewSize.y);
+        if (x >= m_MapWidth) {
+            break;
+        }
+        if (y >= m_MapHeight) {
+            break;
+        }
+
+        if (event.button.button == 1) {
+            if (IsCovered(x, y)) {
+                if (IsMine(x, y)) {
+                    m_IsCoveredBitmap[y] &= ~(1 << x);
+                    m_RunState = MinesweeperRunState::GameOver;
+                }
+                else {
+                    Uncover(x, y);
+                }
+            }
+        }
+        else if (event.button.button == 3) {
+            if (IsCovered(x, y)) {
+                ToggleFlag(x ,y);
+            }
+        }
+
+    } break;
+
+    default:;
+    }
+}
+
+// Todo: maybe find a more efficient non-naive solution
+void Minesweeper::Uncover(int32_t x, int32_t y) {
+    if (x < 0)            return;
+    if (x >= m_MapWidth)  return;
+    if (y < 0)            return;
+    if (y >= m_MapHeight) return;
+    if (!IsCovered(x, y)) return;
+
+    m_IsCoveredBitmap[y] &= ~(1 << x);
+    if (IsFlagged(x, y)) {
+        ToggleFlag(x, y);
+    }
+
+    if (m_AdjacentMineCounters[y*m_MapWidth + x] > 0) {
+        return;
+    }
+    Uncover(x-1, y-1);
+    Uncover(x  , y-1);
+    Uncover(x+1, y-1);
+
+    Uncover(x-1, y);
+    Uncover(x+1, y);
+
+    Uncover(x-1, y+1);
+    Uncover(x  , y+1);
+    Uncover(x+1, y+1);
+}
+
+void Minesweeper::ToggleFlag(int32_t x, int32_t y) {
+    m_IsFlaggedBitmap[y] ^= (1 << x);
+}
+
+bool Minesweeper::IsCovered(int32_t x, int32_t y) {
+    bool is_covered = m_IsCoveredBitmap[y] & 1 << x;
+    return is_covered;
+}
+
+bool Minesweeper::IsFlagged(int32_t x, int32_t y) {
+    bool is_flagged = m_IsFlaggedBitmap[y] & 1 << x;
+    return is_flagged;
+}
+
+bool Minesweeper::IsMine(int32_t x, int32_t y) {
+    bool is_mine = m_IsMineBitmap[y] & 1 << x;
+    return is_mine;
+}
+
+V2F32 Minesweeper::ScreenPosToViewPos(V2F32 screen_pos, RenderGroup &render_group) {
+    // e.g. [0, 1024] -> [0, 1] -> [0, 4]
+    // e.g. [0,  768] -> [0, 1] -> [0, 3]
+    float screen_width = (float)render_group.m_ScreenWidth;
+    float screen_height = (float)render_group.m_ScreenHeight;
+
+    V2F32 view_pos;
+    view_pos.x = (screen_pos.x / screen_width) * m_WorldWidth;
+    view_pos.y = (screen_pos.y / screen_height) * m_WorldHeight;
+    return view_pos;
+}
+
+void Minesweeper::DrawPauseMenu(RenderGroup &render_group) {
+    ImGui::Begin("MinesweeperPause");
+    if (ImGui::Button("Resume")) {
+        m_RunState = MinesweeperRunState::Resume;
+    }
+    if (ImGui::Button("Exit")) {
+        m_RunState = MinesweeperRunState::Exit;
+    }
+    ImGui::End();
+}
+
+void Minesweeper::DrawGameOverMenu(RenderGroup &render_group) {
+    ImGui::Begin("MinesweeperGameOver");
+    ImGui::Text("Score = ???");
+    if (ImGui::Button("Restart")) {
+        m_RunState = MinesweeperRunState::Restart;
+    }
+    if (ImGui::Button("Exit")) {
+        m_RunState = MinesweeperRunState::Exit;
+    }
+    ImGui::End();
+}
+
+void Minesweeper::DrawBoard(RenderGroup &render_group) {
+    V3F32 covered_cell_color = V3F32(0.4f, 0.4f, 0.4f);
+    V3F32 uncovered_cell_color = V3F32(0.2f, 0.2f, 0.2f);
+    V3F32 flag_color = {0.6f, 0.3f, 03.f};
+    V3F32 mine_color = {0.8f, 0.2f, 0.2f};
+
+    V2F32 flag_draw_size = {m_CellInnerViewSize.x * 0.5f, m_CellInnerViewSize.y * 0.5f};
+    V2F32 flag_draw_offset = {
+        (m_CellInnerViewSize.x - flag_draw_size.x) / 2,
+        (m_CellInnerViewSize.y - flag_draw_size.y) / 2
+    };
+
+
+
+    // Todo: avoid if-statement by having them in separate contiguous locations?
+
+    for (int32_t y = 0; y < m_MapHeight; y++) {
+        for (int32_t x = 0; x < m_MapWidth; x++) {
+            V3F32 world_pos = {
+                m_MapViewPos.x + (float)x * m_CellOuterViewSize.x,
+                m_MapViewPos.y + (float)y * m_CellOuterViewSize.y,
+                0.0f
+            };
+            bool is_covered = IsCovered(x, y);
+            bool is_flagged = IsFlagged(x, y);
+            bool is_mine = IsMine(x, y);
+
+            if (is_covered) {
+                render_group.PushRectangle(world_pos, m_CellInnerViewSize, covered_cell_color);
+            }
+            if (is_covered && is_flagged) {
+                assert(IsCovered(x ,y));
+                V3F32 flag_world_pos = {
+                    world_pos.x + flag_draw_offset.x,
+                    world_pos.y + flag_draw_offset.y,
+                    1.0f
+                };
+                render_group.PushRectangle(flag_world_pos, flag_draw_size, flag_color);
+            }
+            if (!is_covered && !is_mine) {
+                render_group.PushRectangle(world_pos, m_CellInnerViewSize, uncovered_cell_color);
+            }
+            if (!is_covered && is_mine) {
+                V3F32 mine_world_pos = {
+                    world_pos.x,
+                    world_pos.y,
+                    2.0f
+                };
+                render_group.PushRectangle(mine_world_pos, m_CellInnerViewSize, mine_color);
+            }
+        }
+    }
+}
+
diff --git a/src/games/minesweeper/Minesweeper.hpp b/src/games/minesweeper/Minesweeper.hpp
new file mode 100644
index 0000000..4906464
--- /dev/null
+++ b/src/games/minesweeper/Minesweeper.hpp
@@ -0,0 +1,81 @@
+#pragma once
+
+#include <games/Game.hpp>
+
+namespace std {
+    template <>
+    struct hash<V2ST> {
+        size_t operator()(const V2ST& v) const {
+            size_t h1 = hash<size_t>{}(v.x);
+            size_t h2 = hash<size_t>{}(v.y);
+            return h1 ^ (h2 << 1);
+        }
+    };
+}
+
+enum class MinesweeperRunState {
+    Resume,
+    Pause,
+    GameOver,
+    Restart,
+    Exit
+};
+
+class Minesweeper : public Game {
+    public:
+        Minesweeper();
+        ~Minesweeper() = default;
+
+        bool Update(std::vector<SDL_Event> &events, RenderGroup &render_group) override;
+
+        void ProcessEventDuringPause(SDL_Event &event, RenderGroup &render_group);
+        void ProcessEventDuringResume(SDL_Event &event, RenderGroup &render_group);
+
+
+    private:
+        void Reinit();
+        void InitIsMineBitmap(int32_t mine_count);
+        void InitAdjacentMineCounters();
+
+        void Uncover(int32_t x, int32_t y);
+        void ToggleFlag(int32_t x, int32_t y);
+
+        bool IsCovered(int32_t x, int32_t y);
+        bool IsFlagged(int32_t x, int32_t y);
+        bool IsMine(int32_t x, int32_t y);
+
+        V2F32 ScreenPosToViewPos(V2F32 screen_pos, RenderGroup &render_group);
+
+
+    private:
+        void DrawPauseMenu(RenderGroup &render_group);
+        void DrawGameOverMenu(RenderGroup &render_group);
+        void DrawBoard(RenderGroup &render_group);
+
+
+    private:
+        static constexpr int32_t MAX_MAP_HEIGHT = 32;
+        static constexpr int32_t MAX_MAP_WIDTH = 32;
+        static constexpr std::string_view s_FontFilepath = "./fonts/dejavu_ttf/DejaVuSans.ttf";
+
+
+    private:
+        MinesweeperRunState m_RunState = MinesweeperRunState::Resume;
+
+        float m_WorldWidth = 4.0f;
+        float m_WorldHeight = 3.0f;
+
+        int32_t m_MapWidth = 16;
+        int32_t m_MapHeight = 16;
+
+        V2F32 m_MapViewPos;
+        V2F32 m_CellOuterViewSize;
+        V2F32 m_CellInnerViewSize;
+
+        uint32_t m_IsCoveredBitmap[MAX_MAP_HEIGHT] {};
+        uint32_t m_IsFlaggedBitmap[MAX_MAP_HEIGHT] {};
+        uint32_t m_IsMineBitmap[MAX_MAP_HEIGHT] {};
+        int32_t m_AdjacentMineCounters[MAX_MAP_WIDTH * MAX_MAP_HEIGHT] {};
+};
+
+