Improve bloom effect (#12916)

* Remove the built-in exposure factor of 2.5
* Add physics-based bloom (https://learnopengl.com/Guest-Articles/2022/Phys.-Based-Bloom)
* Add luminance scaling for bloom layer to simulate HDR
* Add setting to control bloom strength

1 files changed, 12 insertions, 4 deletions

diff --git a/src/client/game.cpp b/src/client/game.cpp
index 5eb185f86..2f97b9b0c 100644
--- a/src/client/game.cpp
+++ b/src/client/game.cpp
@@ -432,6 +432,8 @@ class GameGlobalShaderConstantSetter : public IShaderConstantSetter
 	bool m_bloom_enabled;
 	CachedPixelShaderSetting<float> m_bloom_intensity_pixel;
 	float m_bloom_intensity;
+	CachedPixelShaderSetting<float> m_bloom_strength_pixel;
+	float m_bloom_strength;
 	CachedPixelShaderSetting<float> m_bloom_radius_pixel;
 	float m_bloom_radius;
 
@@ -444,8 +446,10 @@ public:
 			m_user_exposure_factor = g_settings->getFloat("exposure_factor", 0.1f, 10.0f);
 		if (name == "bloom_intensity")
 			m_bloom_intensity = g_settings->getFloat("bloom_intensity", 0.01f, 1.0f);
+		if (name == "bloom_strength_factor")
+			m_bloom_strength = RenderingEngine::BASE_BLOOM_STRENGTH * g_settings->getFloat("bloom_strength_factor", 0.1f, 10.0f);
 		if (name == "bloom_radius")
-			m_bloom_radius = g_settings->getFloat("bloom_radius", 1.0f, 64.0f);
+			m_bloom_radius = g_settings->getFloat("bloom_radius", 0.1f, 8.0f);
 	}
 
 	static void settingsCallback(const std::string &name, void *userdata)
@@ -479,17 +483,20 @@ public:
 		m_texel_size0("texelSize0"),
 		m_exposure_factor_pixel("exposureFactor"),
 		m_bloom_intensity_pixel("bloomIntensity"),
+		m_bloom_strength_pixel("bloomStrength"),
 		m_bloom_radius_pixel("bloomRadius")
 	{
 		g_settings->registerChangedCallback("enable_fog", settingsCallback, this);
 		g_settings->registerChangedCallback("exposure_factor", settingsCallback, this);
 		g_settings->registerChangedCallback("bloom_intensity", settingsCallback, this);
+		g_settings->registerChangedCallback("bloom_strength_factor", settingsCallback, this);
 		g_settings->registerChangedCallback("bloom_radius", settingsCallback, this);
 		m_fog_enabled = g_settings->getBool("enable_fog");
 		m_user_exposure_factor = g_settings->getFloat("exposure_factor", 0.1f, 10.0f);
 		m_bloom_enabled = g_settings->getBool("enable_bloom");
 		m_bloom_intensity = g_settings->getFloat("bloom_intensity", 0.01f, 1.0f);
-		m_bloom_radius = g_settings->getFloat("bloom_radius", 1.0f, 64.0f);
+		m_bloom_strength = RenderingEngine::BASE_BLOOM_STRENGTH * g_settings->getFloat("bloom_strength_factor", 0.1f, 10.0f);
+		m_bloom_radius = g_settings->getFloat("bloom_radius", 0.1f, 8.0f);
 	}
 
 	~GameGlobalShaderConstantSetter()
@@ -567,14 +574,15 @@ public:
 
 		m_texel_size0.set(m_texel_size0_values.data(), services);
 
-		float exposure_factor = RenderingEngine::DEFAULT_EXPOSURE_FACTOR * m_user_exposure_factor;
+		float exposure_factor = m_user_exposure_factor;
 		if (std::isnan(exposure_factor))
-			exposure_factor = RenderingEngine::DEFAULT_EXPOSURE_FACTOR;
+			exposure_factor = 1.0f;
 		m_exposure_factor_pixel.set(&exposure_factor, services);
 
 		if (m_bloom_enabled) {
 			m_bloom_intensity_pixel.set(&m_bloom_intensity, services);
 			m_bloom_radius_pixel.set(&m_bloom_radius, services);
+			m_bloom_strength_pixel.set(&m_bloom_strength, services);
 		}
 	}