transition effect when afvance level

This commit is contained in:
2025-11-29 11:23:05 +01:00
parent 26bdb27209
commit ff8cada8b4

View File

@ -108,15 +108,35 @@ static SDL_Texture* loadTextureFromImage(SDL_Renderer* renderer, const std::stri
return texture;
}
enum class LevelBackgroundPhase { Idle, ZoomOut, ZoomIn };
struct LevelBackgroundFader {
SDL_Texture* currentTex = nullptr;
SDL_Texture* nextTex = nullptr;
int currentLevel = -1;
int queuedLevel = -1;
float fadeElapsedMs = 0.0f;
float phaseElapsedMs = 0.0f;
float phaseDurationMs = 0.0f;
float fadeDurationMs = Config::Gameplay::LEVEL_FADE_DURATION;
LevelBackgroundPhase phase = LevelBackgroundPhase::Idle;
};
static float getPhaseDurationMs(const LevelBackgroundFader& fader, LevelBackgroundPhase phase) {
const float total = std::max(1200.0f, fader.fadeDurationMs);
switch (phase) {
case LevelBackgroundPhase::ZoomOut: return total * 0.45f;
case LevelBackgroundPhase::ZoomIn: return total * 0.45f;
case LevelBackgroundPhase::Idle:
default: return 0.0f;
}
}
static void setPhase(LevelBackgroundFader& fader, LevelBackgroundPhase nextPhase) {
fader.phase = nextPhase;
fader.phaseDurationMs = getPhaseDurationMs(fader, nextPhase);
fader.phaseElapsedMs = 0.0f;
}
static void destroyTexture(SDL_Texture*& tex) {
if (tex) {
SDL_DestroyTexture(tex);
@ -146,32 +166,90 @@ static bool queueLevelBackground(LevelBackgroundFader& fader, SDL_Renderer* rend
destroyTexture(fader.nextTex);
fader.nextTex = newTexture;
fader.queuedLevel = level;
fader.fadeElapsedMs = 0.0f;
if (!fader.currentTex) {
// First background load happens instantly.
fader.currentTex = fader.nextTex;
fader.currentLevel = fader.queuedLevel;
fader.nextTex = nullptr;
fader.queuedLevel = -1;
fader.phase = LevelBackgroundPhase::Idle;
fader.phaseElapsedMs = 0.0f;
fader.phaseDurationMs = 0.0f;
} else if (fader.phase == LevelBackgroundPhase::Idle) {
// Kick off fancy transition.
setPhase(fader, LevelBackgroundPhase::ZoomOut);
}
return true;
}
static void updateLevelBackgroundFade(LevelBackgroundFader& fader, float frameMs) {
if (!fader.currentTex || !fader.nextTex) {
if (fader.phase == LevelBackgroundPhase::Idle) {
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;
// Guard against missing textures
if (!fader.currentTex && !fader.nextTex) {
fader.phase = LevelBackgroundPhase::Idle;
return;
}
fader.phaseElapsedMs += frameMs;
if (fader.phaseElapsedMs < std::max(1.0f, fader.phaseDurationMs)) {
return;
}
switch (fader.phase) {
case LevelBackgroundPhase::ZoomOut:
// After zoom-out, swap textures then start zoom-in.
if (fader.nextTex) {
destroyTexture(fader.currentTex);
fader.currentTex = fader.nextTex;
fader.currentLevel = fader.queuedLevel;
fader.nextTex = nullptr;
fader.queuedLevel = -1;
}
setPhase(fader, LevelBackgroundPhase::ZoomIn);
break;
case LevelBackgroundPhase::ZoomIn:
fader.phase = LevelBackgroundPhase::Idle;
fader.phaseElapsedMs = 0.0f;
fader.phaseDurationMs = 0.0f;
break;
case LevelBackgroundPhase::Idle:
default:
fader.phase = LevelBackgroundPhase::Idle;
break;
}
}
static void renderScaledBackground(SDL_Renderer* renderer, SDL_Texture* tex, int winW, int winH, float scale, Uint8 alpha = 255) {
if (!renderer || !tex) {
return;
}
scale = std::max(0.5f, scale);
SDL_FRect dest{
(winW - winW * scale) * 0.5f,
(winH - winH * scale) * 0.5f,
winW * scale,
winH * scale
};
SDL_SetTextureAlphaMod(tex, alpha);
SDL_RenderTexture(renderer, tex, nullptr, &dest);
SDL_SetTextureAlphaMod(tex, 255);
}
static void drawOverlay(SDL_Renderer* renderer, const SDL_FRect& rect, SDL_Color color, Uint8 alpha) {
if (!renderer || alpha == 0) {
return;
}
SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_BLEND);
SDL_SetRenderDrawColor(renderer, color.r, color.g, color.b, alpha);
SDL_RenderFillRect(renderer, &rect);
SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_NONE);
}
static void renderLevelBackgrounds(const LevelBackgroundFader& fader, SDL_Renderer* renderer, int winW, int winH) {
@ -180,22 +258,36 @@ static void renderLevelBackgrounds(const LevelBackgroundFader& fader, SDL_Render
}
SDL_FRect fullRect{0.f, 0.f, static_cast<float>(winW), static_cast<float>(winH)};
const float duration = std::max(1.0f, fader.phaseDurationMs);
const float progress = (fader.phase == LevelBackgroundPhase::Idle) ? 0.0f : std::clamp(fader.phaseElapsedMs / duration, 0.0f, 1.0f);
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);
switch (fader.phase) {
case LevelBackgroundPhase::ZoomOut: {
const float scale = 1.0f + progress * 0.15f;
if (fader.currentTex) {
renderScaledBackground(renderer, fader.currentTex, winW, winH, scale, Uint8((1.0f - progress * 0.4f) * 255.0f));
drawOverlay(renderer, fullRect, SDL_Color{0, 0, 0, 255}, Uint8(progress * 200.0f));
}
break;
}
case LevelBackgroundPhase::ZoomIn: {
const float scale = 1.10f - progress * 0.10f;
const Uint8 alpha = Uint8((0.4f + progress * 0.6f) * 255.0f);
if (fader.currentTex) {
renderScaledBackground(renderer, fader.currentTex, winW, winH, scale, alpha);
}
break;
}
case LevelBackgroundPhase::Idle:
default:
if (fader.currentTex) {
renderScaledBackground(renderer, fader.currentTex, winW, winH, 1.0f, 255);
} else if (fader.nextTex) {
renderScaledBackground(renderer, fader.nextTex, winW, winH, 1.0f, 255);
} else {
drawOverlay(renderer, fullRect, SDL_Color{0, 0, 0, 255}, 255);
}
break;
}
}
@ -204,7 +296,9 @@ static void resetLevelBackgrounds(LevelBackgroundFader& fader) {
destroyTexture(fader.nextTex);
fader.currentLevel = -1;
fader.queuedLevel = -1;
fader.fadeElapsedMs = 0.0f;
fader.phaseElapsedMs = 0.0f;
fader.phaseDurationMs = 0.0f;
fader.phase = LevelBackgroundPhase::Idle;
}
// Hover state for level popup ( -1 = none, 0..19 = hovered level )