added transition from levels

src/main.cpp

@@ -106,6 +106,105 @@ static SDL_Texture* loadTextureFromImage(SDL_Renderer* renderer, const std::stri
     return texture;
 }
 
+struct LevelBackgroundFader {
+    SDL_Texture* currentTex = nullptr;
+    SDL_Texture* nextTex = nullptr;
+    int currentLevel = -1;
+    int queuedLevel = -1;
+    float fadeElapsedMs = 0.0f;
+    float fadeDurationMs = 3500.0f;
+};
+
+static void destroyTexture(SDL_Texture*& tex) {
+    if (tex) {
+        SDL_DestroyTexture(tex);
+        tex = nullptr;
+    }
+}
+
+static bool queueLevelBackground(LevelBackgroundFader& fader, SDL_Renderer* renderer, int level) {
+    if (!renderer) {
+        return false;
+    }
+
+    level = std::clamp(level, 0, 32);
+    if (fader.currentLevel == level || fader.queuedLevel == level) {
+        return true;
+    }
+
+    char bgPath[256];
+    std::snprintf(bgPath, sizeof(bgPath), "assets/images/tetris_main_back_level%d.jpg", level);
+
+    SDL_Texture* newTexture = loadTextureFromImage(renderer, bgPath);
+    if (!newTexture) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to queue background for level %d: %s", level, bgPath);
+        return false;
+    }
+
+    destroyTexture(fader.nextTex);
+    fader.nextTex = newTexture;
+    fader.queuedLevel = level;
+    fader.fadeElapsedMs = 0.0f;
+
+    if (!fader.currentTex) {
+        fader.currentTex = fader.nextTex;
+        fader.currentLevel = fader.queuedLevel;
+        fader.nextTex = nullptr;
+        fader.queuedLevel = -1;
+    }
+
+    return true;
+}
+
+static void updateLevelBackgroundFade(LevelBackgroundFader& fader, float frameMs) {
+    if (!fader.currentTex || !fader.nextTex) {
+        return;
+    }
+
+    fader.fadeElapsedMs += frameMs;
+    if (fader.fadeElapsedMs >= fader.fadeDurationMs) {
+        destroyTexture(fader.currentTex);
+        fader.currentTex = fader.nextTex;
+        fader.currentLevel = fader.queuedLevel;
+        fader.nextTex = nullptr;
+        fader.queuedLevel = -1;
+        fader.fadeElapsedMs = 0.0f;
+    }
+}
+
+static void renderLevelBackgrounds(const LevelBackgroundFader& fader, SDL_Renderer* renderer, int winW, int winH) {
+    if (!renderer) {
+        return;
+    }
+
+    SDL_FRect fullRect{0.f, 0.f, static_cast<float>(winW), static_cast<float>(winH)};
+
+    if (fader.currentTex && fader.nextTex) {
+        const float duration = std::max(1.0f, fader.fadeDurationMs);
+        const float alpha = std::clamp(fader.fadeElapsedMs / duration, 0.0f, 1.0f);
+
+        SDL_SetTextureAlphaMod(fader.currentTex, Uint8((1.0f - alpha) * 255.0f));
+        SDL_RenderTexture(renderer, fader.currentTex, nullptr, &fullRect);
+        SDL_SetTextureAlphaMod(fader.currentTex, 255);
+
+        SDL_SetTextureAlphaMod(fader.nextTex, Uint8(alpha * 255.0f));
+        SDL_RenderTexture(renderer, fader.nextTex, nullptr, &fullRect);
+        SDL_SetTextureAlphaMod(fader.nextTex, 255);
+    } else if (fader.currentTex) {
+        SDL_RenderTexture(renderer, fader.currentTex, nullptr, &fullRect);
+    } else if (fader.nextTex) {
+        SDL_RenderTexture(renderer, fader.nextTex, nullptr, &fullRect);
+    }
+}
+
+static void resetLevelBackgrounds(LevelBackgroundFader& fader) {
+    destroyTexture(fader.currentTex);
+    destroyTexture(fader.nextTex);
+    fader.currentLevel = -1;
+    fader.queuedLevel = -1;
+    fader.fadeElapsedMs = 0.0f;
+}
+
 // Hover state for level popup ( -1 = none, 0..19 = hovered level )
 // Now managed by LevelSelectorState
 
@@ -501,12 +600,7 @@ int main(int, char **)
     // States should render using `ctx.backgroundTex` rather than accessing globals.
     
     // Level background caching system
-    SDL_Texture *levelBackgroundTex = nullptr;
+    LevelBackgroundFader levelBackgrounds;
-    SDL_Texture *nextLevelBackgroundTex = nullptr; // used during fade transitions
-    int cachedLevel = -1; // Track which level background is currently cached
-    float levelFadeAlpha = 0.0f; // 0..1 blend factor where 1 means next fully visible
-    const float LEVEL_FADE_DURATION = 3500.0f; // ms for fade transition (3.5s)
-    float levelFadeElapsed = 0.0f;
 
     // Default start level selection: 0 (declare here so it's in scope for all handlers)
     int startLevelSelection = 0;
@@ -1180,10 +1274,7 @@ int main(int, char **)
         }
 
         // Advance level background fade if a next texture is queued
-        if (nextLevelBackgroundTex) {
+        updateLevelBackgroundFade(levelBackgrounds, float(frameMs));
-            levelFadeElapsed += float(frameMs);
-            levelFadeAlpha = std::min(1.0f, levelFadeElapsed / LEVEL_FADE_DURATION);
-        }
         
         // Update intro animations
         if (state == AppState::Menu) {
@@ -1276,58 +1367,9 @@ int main(int, char **)
         
     // Draw level-based background for gameplay, starfield for other states
     if (state == AppState::Playing) {
-        // Use level-based background for gameplay with caching
+        int bgLevel = std::clamp(game.level(), 0, 32);
-        int currentLevel = game.level();
+        queueLevelBackground(levelBackgrounds, renderer, bgLevel);
-        int bgLevel = (currentLevel > 32) ? 32 : currentLevel; // Cap at level 32
+        renderLevelBackgrounds(levelBackgrounds, renderer, winW, winH);
-        
-        // Only load new background if level changed
-        if (cachedLevel != bgLevel) {
-            // Load new level background into nextLevelBackgroundTex
-            if (nextLevelBackgroundTex) { SDL_DestroyTexture(nextLevelBackgroundTex); nextLevelBackgroundTex = nullptr; }
-            char bgPath[256];
-            snprintf(bgPath, sizeof(bgPath), "assets/images/tetris_main_back_level%d.jpg", bgLevel);
-            SDL_Texture* newLevelTex = loadTextureFromImage(renderer, bgPath);
-            if (newLevelTex) {
-                SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION, "Loaded background for level %d: %s", bgLevel, bgPath);
-                nextLevelBackgroundTex = newLevelTex;
-                // start fade transition
-                levelFadeAlpha = 0.0f;
-                levelFadeElapsed = 0.0f;
-                cachedLevel = bgLevel;
-            } else {
-                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to load background for level %d: %s", bgLevel, bgPath);
-                // don't change textures if file missing
-                cachedLevel = -1;
-            }
-        }
-
-        // Draw blended backgrounds if needed
-        if (levelBackgroundTex || nextLevelBackgroundTex) {
-            // Use actual window pixel size so backgrounds always cover full screen
-            SDL_FRect fullRect = { 0, 0, (float)winW, (float)winH };
-            // if fade in progress
-            if (nextLevelBackgroundTex && levelFadeAlpha < 1.0f && levelBackgroundTex) {
-                // draw current with inverse alpha
-                SDL_SetTextureAlphaMod(levelBackgroundTex, Uint8((1.0f - levelFadeAlpha) * 255));
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-                SDL_SetTextureAlphaMod(nextLevelBackgroundTex, Uint8(levelFadeAlpha * 255));
-                SDL_RenderTexture(renderer, nextLevelBackgroundTex, nullptr, &fullRect);
-                // reset mods
-                SDL_SetTextureAlphaMod(levelBackgroundTex, 255);
-                SDL_SetTextureAlphaMod(nextLevelBackgroundTex, 255);
-            }
-            else if (nextLevelBackgroundTex && (!levelBackgroundTex || levelFadeAlpha >= 1.0f)) {
-                // finalise swap
-                if (levelBackgroundTex) { SDL_DestroyTexture(levelBackgroundTex); }
-                levelBackgroundTex = nextLevelBackgroundTex;
-                nextLevelBackgroundTex = nullptr;
-                levelFadeAlpha = 0.0f;
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-            }
-            else if (levelBackgroundTex) {
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-            }
-        }
     } else if (state == AppState::Loading) {
         // Use 3D starfield for loading screen (full screen)
         starfield3D.draw(renderer);
@@ -1648,10 +1690,7 @@ int main(int, char **)
         SDL_DestroyTexture(logoTex);
     if (backgroundTex)
         SDL_DestroyTexture(backgroundTex);
-    if (nextLevelBackgroundTex)
+    resetLevelBackgrounds(levelBackgrounds);
-        SDL_DestroyTexture(nextLevelBackgroundTex);
-    if (levelBackgroundTex)
-        SDL_DestroyTexture(levelBackgroundTex);
     if (blocksTex)
         SDL_DestroyTexture(blocksTex);
     if (logoSmallTex)

src/main_dist.cpp

@@ -105,6 +105,105 @@ static SDL_Texture* loadTextureFromImage(SDL_Renderer* renderer, const std::stri
     return texture;
 }
 
+struct LevelBackgroundFader {
+    SDL_Texture* currentTex = nullptr;
+    SDL_Texture* nextTex = nullptr;
+    int currentLevel = -1;
+    int queuedLevel = -1;
+    float fadeElapsedMs = 0.0f;
+    float fadeDurationMs = 3500.0f;
+};
+
+static void destroyTexture(SDL_Texture*& tex) {
+    if (tex) {
+        SDL_DestroyTexture(tex);
+        tex = nullptr;
+    }
+}
+
+static bool queueLevelBackground(LevelBackgroundFader& fader, SDL_Renderer* renderer, int level) {
+    if (!renderer) {
+        return false;
+    }
+
+    level = std::clamp(level, 0, 32);
+    if (fader.currentLevel == level || fader.queuedLevel == level) {
+        return true;
+    }
+
+    char bgPath[256];
+    std::snprintf(bgPath, sizeof(bgPath), "assets/images/tetris_main_back_level%d.jpg", level);
+
+    SDL_Texture* newTexture = loadTextureFromImage(renderer, bgPath);
+    if (!newTexture) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to queue background for level %d: %s", level, bgPath);
+        return false;
+    }
+
+    destroyTexture(fader.nextTex);
+    fader.nextTex = newTexture;
+    fader.queuedLevel = level;
+    fader.fadeElapsedMs = 0.0f;
+
+    if (!fader.currentTex) {
+        fader.currentTex = fader.nextTex;
+        fader.currentLevel = fader.queuedLevel;
+        fader.nextTex = nullptr;
+        fader.queuedLevel = -1;
+    }
+
+    return true;
+}
+
+static void updateLevelBackgroundFade(LevelBackgroundFader& fader, float frameMs) {
+    if (!fader.currentTex || !fader.nextTex) {
+        return;
+    }
+
+    fader.fadeElapsedMs += frameMs;
+    if (fader.fadeElapsedMs >= fader.fadeDurationMs) {
+        destroyTexture(fader.currentTex);
+        fader.currentTex = fader.nextTex;
+        fader.currentLevel = fader.queuedLevel;
+        fader.nextTex = nullptr;
+        fader.queuedLevel = -1;
+        fader.fadeElapsedMs = 0.0f;
+    }
+}
+
+static void renderLevelBackgrounds(const LevelBackgroundFader& fader, SDL_Renderer* renderer, int winW, int winH) {
+    if (!renderer) {
+        return;
+    }
+
+    SDL_FRect fullRect{0.f, 0.f, static_cast<float>(winW), static_cast<float>(winH)};
+
+    if (fader.currentTex && fader.nextTex) {
+        const float duration = std::max(1.0f, fader.fadeDurationMs);
+        const float alpha = std::clamp(fader.fadeElapsedMs / duration, 0.0f, 1.0f);
+
+        SDL_SetTextureAlphaMod(fader.currentTex, Uint8((1.0f - alpha) * 255.0f));
+        SDL_RenderTexture(renderer, fader.currentTex, nullptr, &fullRect);
+        SDL_SetTextureAlphaMod(fader.currentTex, 255);
+
+        SDL_SetTextureAlphaMod(fader.nextTex, Uint8(alpha * 255.0f));
+        SDL_RenderTexture(renderer, fader.nextTex, nullptr, &fullRect);
+        SDL_SetTextureAlphaMod(fader.nextTex, 255);
+    } else if (fader.currentTex) {
+        SDL_RenderTexture(renderer, fader.currentTex, nullptr, &fullRect);
+    } else if (fader.nextTex) {
+        SDL_RenderTexture(renderer, fader.nextTex, nullptr, &fullRect);
+    }
+}
+
+static void resetLevelBackgrounds(LevelBackgroundFader& fader) {
+    destroyTexture(fader.currentTex);
+    destroyTexture(fader.nextTex);
+    fader.currentLevel = -1;
+    fader.queuedLevel = -1;
+    fader.fadeElapsedMs = 0.0f;
+}
+
 // Hover state for level popup ( -1 = none, 0..19 = hovered level )
 // Now managed by LevelSelectorState
 
@@ -495,12 +594,7 @@ int main(int, char **)
     // States should render using `ctx.backgroundTex` rather than accessing globals.
     
     // Level background caching system
-    SDL_Texture *levelBackgroundTex = nullptr;
+    LevelBackgroundFader levelBackgrounds;
-    SDL_Texture *nextLevelBackgroundTex = nullptr; // used during fade transitions
-    int cachedLevel = -1; // Track which level background is currently cached
-    float levelFadeAlpha = 0.0f; // 0..1 blend factor where 1 means next fully visible
-    const float LEVEL_FADE_DURATION = 3500.0f; // ms for fade transition (3.5s)
-    float levelFadeElapsed = 0.0f;
 
     // Default start level selection: 0 (declare here so it's in scope for all handlers)
     int startLevelSelection = 0;
@@ -815,7 +909,6 @@ int main(int, char **)
                                     exitPopupSelectedButton = 1;
                                 }
 
-                                // Settings button (gear icon area - top right)
                                 SDL_FRect settingsBtn{LOGICAL_W - 60, 10, 50, 30};
                                 if (lx >= settingsBtn.x && lx <= settingsBtn.x + settingsBtn.w && ly >= settingsBtn.y && ly <= settingsBtn.y + settingsBtn.h)
                                 {
@@ -830,48 +923,6 @@ int main(int, char **)
                             stateMgr.setState(state);
                         }
                         else if (state == AppState::Playing && showExitConfirmPopup) {
-                            // Convert mouse to logical coordinates and to content-local coords
-                            float lx = (mx - logicalVP.x) / logicalScale;
-                            float ly = (my - logicalVP.y) / logicalScale;
-                            // Compute content offsets (same as in render path)
-                            float contentW = LOGICAL_W * logicalScale;
-                            float contentH = LOGICAL_H * logicalScale;
-                            float contentOffsetX = (winW - contentW) * 0.5f / logicalScale;
-                            float contentOffsetY = (winH - contentH) * 0.5f / logicalScale;
-                            // Map to content-local logical coords (what drawing code uses)
-                            float localX = lx - contentOffsetX;
-                            float localY = ly - contentOffsetY;
-
-                            // Popup rect in logical coordinates (content-local)
-                            float popupW = 400, popupH = 200;
-                            float popupX = (LOGICAL_W - popupW) / 2.0f;
-                            float popupY = (LOGICAL_H - popupH) / 2.0f;
-                            // Simple Yes/No buttons
-                            float btnW = 120.0f, btnH = 40.0f;
-                            float yesX = popupX + popupW * 0.25f - btnW / 2.0f;
-                            float noX = popupX + popupW * 0.75f - btnW / 2.0f;
-                            float btnY = popupY + popupH - btnH - 20.0f;
-
-                            if (localX >= popupX && localX <= popupX + popupW && localY >= popupY && localY <= popupY + popupH) {
-                                // Click inside popup - check buttons
-                                if (localX >= yesX && localX <= yesX + btnW && localY >= btnY && localY <= btnY + btnH) {
-                                    // Yes -> go back to menu
-                                    showExitConfirmPopup = false;
-                                    game.reset(startLevelSelection);
-                                    state = AppState::Menu;
-                                    stateMgr.setState(state);
-                                } else if (localX >= noX && localX <= noX + btnW && localY >= btnY && localY <= btnY + btnH) {
-                                    // No -> close popup and resume
-                                    showExitConfirmPopup = false;
-                                    game.setPaused(false);
-                                }
-                            } else {
-                                // Click outside popup: cancel
-                                showExitConfirmPopup = false;
-                                game.setPaused(false);
-                            }
-                        }
-                        else if (state == AppState::Menu && showExitConfirmPopup) {
                             float contentW = LOGICAL_W * logicalScale;
                             float contentH = LOGICAL_H * logicalScale;
                             float contentOffsetX = (winW - contentW) * 0.5f / logicalScale;
@@ -1088,10 +1139,7 @@ int main(int, char **)
         }
 
         // Advance level background fade if a next texture is queued
-        if (nextLevelBackgroundTex) {
+        updateLevelBackgroundFade(levelBackgrounds, float(frameMs));
-            levelFadeElapsed += float(frameMs);
-            levelFadeAlpha = std::min(1.0f, levelFadeElapsed / LEVEL_FADE_DURATION);
-        }
         
         // Update intro animations
         if (state == AppState::Menu) {
@@ -1124,56 +1172,9 @@ int main(int, char **)
         
     // Draw level-based background for gameplay, starfield for other states
     if (state == AppState::Playing) {
-        // Use level-based background for gameplay with caching
+        int bgLevel = std::clamp(game.level(), 0, 32);
-        int currentLevel = game.level();
+        queueLevelBackground(levelBackgrounds, renderer, bgLevel);
-        int bgLevel = (currentLevel > 32) ? 32 : currentLevel; // Cap at level 32
+        renderLevelBackgrounds(levelBackgrounds, renderer, winW, winH);
-        
-        // Only load new background if level changed
-        if (cachedLevel != bgLevel) {
-            // Load new level background into nextLevelBackgroundTex
-            if (nextLevelBackgroundTex) { SDL_DestroyTexture(nextLevelBackgroundTex); nextLevelBackgroundTex = nullptr; }
-            char bgPath[256];
-            snprintf(bgPath, sizeof(bgPath), "assets/images/tetris_main_back_level%d.jpg", bgLevel);
-            SDL_Texture* newLevelTex = loadTextureFromImage(renderer, bgPath);
-            if (newLevelTex) {
-                nextLevelBackgroundTex = newLevelTex;
-                // start fade transition
-                levelFadeAlpha = 0.0f;
-                levelFadeElapsed = 0.0f;
-                cachedLevel = bgLevel;
-            } else {
-                // don't change textures if file missing
-                cachedLevel = -1;
-            }
-        }
-
-        // Draw blended backgrounds if needed
-        if (levelBackgroundTex || nextLevelBackgroundTex) {
-            // Use actual window pixel size so backgrounds always cover full screen
-            SDL_FRect fullRect = { 0, 0, (float)winW, (float)winH };
-            // if fade in progress
-            if (nextLevelBackgroundTex && levelFadeAlpha < 1.0f && levelBackgroundTex) {
-                // draw current with inverse alpha
-                SDL_SetTextureAlphaMod(levelBackgroundTex, Uint8((1.0f - levelFadeAlpha) * 255));
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-                SDL_SetTextureAlphaMod(nextLevelBackgroundTex, Uint8(levelFadeAlpha * 255));
-                SDL_RenderTexture(renderer, nextLevelBackgroundTex, nullptr, &fullRect);
-                // reset mods
-                SDL_SetTextureAlphaMod(levelBackgroundTex, 255);
-                SDL_SetTextureAlphaMod(nextLevelBackgroundTex, 255);
-            }
-            else if (nextLevelBackgroundTex && (!levelBackgroundTex || levelFadeAlpha >= 1.0f)) {
-                // finalise swap
-                if (levelBackgroundTex) { SDL_DestroyTexture(levelBackgroundTex); }
-                levelBackgroundTex = nextLevelBackgroundTex;
-                nextLevelBackgroundTex = nullptr;
-                levelFadeAlpha = 0.0f;
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-            }
-            else if (levelBackgroundTex) {
-                SDL_RenderTexture(renderer, levelBackgroundTex, nullptr, &fullRect);
-            }
-        }
     } else if (state == AppState::Loading) {
         // Use 3D starfield for loading screen (full screen)
         starfield3D.draw(renderer);
@@ -1714,10 +1715,7 @@ int main(int, char **)
         SDL_DestroyTexture(logoTex);
     if (backgroundTex)
         SDL_DestroyTexture(backgroundTex);
-    if (nextLevelBackgroundTex)
+    resetLevelBackgrounds(levelBackgrounds);
-        SDL_DestroyTexture(nextLevelBackgroundTex);
-    if (levelBackgroundTex)
-        SDL_DestroyTexture(levelBackgroundTex);
     if (blocksTex)
         SDL_DestroyTexture(blocksTex);
     if (logoSmallTex)