Slightly improves minimap flares, makes animation more smooth via alpha fade in/out.

Tested By: Langbart
Differential Revision: https://code.wildfiregames.com/D4351
This was SVN commit r26001.

binaries/data/mods/mod/gui/gui.rng

@@ -242,7 +242,7 @@
       </optional>
       <optional>
         <attribute name="flare_animation_speed">
-          <data type="nonNegativeInteger"/>
+          <data type="decimal"/>
         </attribute>
       </optional>
       <optional>
@@ -252,7 +252,17 @@
       </optional>
       <optional>
         <attribute name="flare_lifetime_seconds">
-          <data type="nonNegativeInteger"/>
+          <data type="decimal"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="flare_start_fade_seconds">
+          <data type="decimal"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="flare_stop_fade_seconds">
+          <data type="decimal"/>
         </attribute>
       </optional>
       <optional>

binaries/data/mods/public/gui/session/minimap/MiniMap.xml

@@ -63,8 +63,10 @@
 		mask="true"
 		flare_texture_count="16"
 		flare_render_size="32"
-		flare_animation_speed="11"
+		flare_animation_speed="10.67"
 		flare_interleave="true"
 		flare_lifetime_seconds="6"
+		flare_start_fade_seconds="0.25"
+		flare_stop_fade_seconds="0.5"
 	/>
 </object>

source/gui/ObjectTypes/CMiniMap.cpp

@@ -36,6 +36,7 @@
 #include "lib/external_libraries/libsdl.h"
 #include "lib/ogl.h"
 #include "lib/timer.h"
+#include "maths/MathUtil.h"
 #include "ps/CLogger.h"
 #include "ps/ConfigDB.h"
 #include "ps/CStrInternStatic.h"
@@ -136,7 +137,9 @@ CMiniMap::CMiniMap(CGUI& pGUI) :
 	m_MapSize(0), m_MapScale(1.f), m_Mask(this, "mask", false),
 	m_FlareTextureCount(this, "flare_texture_count", 0), m_FlareRenderSize(this, "flare_render_size", 0),
 	m_FlareInterleave(this, "flare_interleave", false), m_FlareAnimationSpeed(this, "flare_animation_speed", 0.0f),
-	m_FlareLifetimeSeconds(this, "flare_lifetime_seconds", 0.0f)
+	m_FlareLifetimeSeconds(this, "flare_lifetime_seconds", 0.0f),
+	m_FlareStartFadeSeconds(this, "flare_start_fade_seconds", 0.0f),
+	m_FlareStopFadeSeconds(this, "flare_stop_fade_seconds", 0.0f)
 {
 	m_Clicking = false;
 	m_MouseHovering = false;
@@ -341,21 +344,38 @@ void CMiniMap::DrawFlare(CCanvas2D& canvas, const MapFlare& flare, double curren
 		flareCenter.X - m_FlareRenderSize, flareCenter.Y - m_FlareRenderSize,
 		flareCenter.X + m_FlareRenderSize, flareCenter.Y + m_FlareRenderSize);
 
-	const u32 flooredStep = floor((currentTime - flare.time) * m_FlareAnimationSpeed);
+	const double deltaTime = currentTime - flare.time;
+	const double remainingTime = m_FlareLifetimeSeconds - deltaTime;
+	const u32 flooredStep = floor(deltaTime * m_FlareAnimationSpeed);
 
-	CTexturePtr texture = m_FlareTextures[flooredStep % m_FlareTextures.size()];
+	const float startFadeAlpha = m_FlareStartFadeSeconds > 0.0f ? deltaTime / m_FlareStartFadeSeconds : 1.0f;
-	// TODO: Only draw inside the minimap circle.
+	const float stopFadeAlpha = m_FlareStopFadeSeconds > 0.0f ? remainingTime / m_FlareStopFadeSeconds : 1.0f;
-	canvas.DrawTexture(texture, destination, CRect(0, 0, texture->GetWidth(), texture->GetHeight()), flare.color, CColor(0.0f, 0.0f, 0.0f, 0.0f), 0.0f);
+	const float alpha = Clamp(std::min(
+		SmoothStep(0.0f, 1.0f, startFadeAlpha), SmoothStep(0.0f, 1.0f, stopFadeAlpha)),
+		0.0f, 1.0f);
 
-	// Draw a second circle if the first has reached half of the animation
+	DrawFlareFrame(canvas, flooredStep % m_FlareTextures.size(), destination, flare.color, alpha);
+
+	// Draw a second circle if the first has reached half of the animation.
 	if (m_FlareInterleave && flooredStep >= m_FlareTextures.size() / 2)
 	{
-		texture = m_FlareTextures[(flooredStep - m_FlareTextures.size() / 2) % m_FlareTextures.size()];
+		DrawFlareFrame(canvas, (flooredStep - m_FlareTextures.size() / 2) % m_FlareTextures.size(),
-		// TODO: Only draw inside the minimap circle.
+			destination, flare.color, alpha);
-		canvas.DrawTexture(texture, destination, CRect(0, 0, texture->GetWidth(), texture->GetHeight()), flare.color, CColor(0.0f, 0.0f, 0.0f, 0.0f), 0.0f);
 	}
 }
 
+void CMiniMap::DrawFlareFrame(CCanvas2D& canvas, const u32 frameIndex,
+	const CRect& destination, const CColor& color, float alpha) const
+{
+	// TODO: Only draw inside the minimap circle.
+	CTexturePtr texture = m_FlareTextures[frameIndex % m_FlareTextures.size()];
+	CColor finalColor = color;
+	finalColor.a *= alpha;
+	canvas.DrawTexture(texture, destination,
+		CRect(0, 0, texture->GetWidth(), texture->GetHeight()), finalColor,
+		CColor(0.0f, 0.0f, 0.0f, 0.0f), 0.0f);
+}
+
 void CMiniMap::Draw(CCanvas2D& canvas)
 {
 	PROFILE3("render minimap");

source/gui/ObjectTypes/CMiniMap.h

@@ -80,6 +80,8 @@ private:
 	CGUISimpleSetting<bool> m_FlareInterleave;
 	CGUISimpleSetting<float> m_FlareAnimationSpeed;
 	CGUISimpleSetting<float> m_FlareLifetimeSeconds;
+	CGUISimpleSetting<float> m_FlareStartFadeSeconds;
+	CGUISimpleSetting<float> m_FlareStopFadeSeconds;
 
 	// Whether to draw a black square around and under the minimap.
 	CGUISimpleSetting<bool> m_Mask;
@@ -94,7 +96,8 @@ private:
 
 	void DrawViewRect(CCanvas2D& canvas) const;
 
-	void DrawFlare(CCanvas2D& canvas, const MapFlare& flare, double curentTime) const;
+	void DrawFlare(CCanvas2D& canvas, const MapFlare& flare, double currentTime) const;
+	void DrawFlareFrame(CCanvas2D& canvas, const u32 frameIndex, const CRect& destination, const CColor& color, float alpha) const;
 
 	void GetMouseWorldCoordinates(float& x, float& z) const;
 

source/maths/MathUtil.h

@@ -22,13 +22,13 @@
 #define RADTODEG(a)					((a) * (180.0f/(float)M_PI))
 #define SQR(x)						((x) * (x))
 
-template <typename T>
+template<typename T>
 inline T Interpolate(const T& a, const T& b, float t)
 {
 	return a + (b - a) * t;
 }
 
-template <typename T>
+template<typename T>
 inline T Clamp(T value, T min, T max)
 {
 	if (value <= min)
@@ -38,6 +38,13 @@ inline T Clamp(T value, T min, T max)
 	return value;
 }
 
+template<typename T>
+inline T SmoothStep(T edge0, T edge1, T value)
+{
+	value = Clamp<T>((value - edge0) / (edge1 - edge0), 0, 1); 
+	return value * value * (3 - 2 * value);
+}
+
 inline float sgn(float a)
 {
     if (a > 0.0f)