Merged in SL-16127_More_tweaks (pull request #752)

SL-16127 More tweaks

Approved-by: Euclid Linden
Approved-by: Dave Parks

10 files changed, 105 insertions, 110 deletions

diff --git a/doc/contributions.txt b/doc/contributions.txt
index 537df59c8c..33b169169c 100755
--- a/doc/contributions.txt
+++ b/doc/contributions.txt
@@ -1367,6 +1367,7 @@ Sovereign Engineer
 	SL-14731
 	SL-14732
 	SL-15096
+	SL-16127
 SpacedOut Frye
 	VWR-34
 	VWR-45
diff --git a/indra/llinventory/llsettingssky.cpp b/indra/llinventory/llsettingssky.cpp
index 23f9c8e9d7..0ada97ad3f 100644
--- a/indra/llinventory/llsettingssky.cpp
+++ b/indra/llinventory/llsettingssky.cpp
@@ -1214,9 +1214,9 @@ LLColor3 LLSettingsSky::getLightTransmittanceFast( const LLColor3& total_density
 
 // performs soft scale clip and gamma correction ala the shader implementation
 // scales colors down to 0 - 1 range preserving relative ratios
-LLColor3 LLSettingsSky::gammaCorrect(const LLColor3& in) const
+LLColor3 LLSettingsSky::gammaCorrect(const LLColor3& in,const F32 &gamma) const
 {
-    F32 gamma = getGamma();
+    //F32 gamma = getGamma(); // SL-16127: Use cached gamma from atmospheric vars
 
     LLColor3 v(in);
     // scale down to 0 to 1 range preserving relative ratio (aka homegenize)
diff --git a/indra/llinventory/llsettingssky.h b/indra/llinventory/llsettingssky.h
index 77d9d8e87c..fa9326f006 100644
--- a/indra/llinventory/llsettingssky.h
+++ b/indra/llinventory/llsettingssky.h
@@ -254,7 +254,7 @@ public:
     LLColor3 getLightTransmittance(F32 distance) const;
     LLColor3 getLightTransmittanceFast(const LLColor3& total_density, const F32 density_multiplier, const F32 distance) const;
     LLColor3 getTotalDensity() const;
-    LLColor3 gammaCorrect(const LLColor3& in) const;
+    LLColor3 gammaCorrect(const LLColor3& in,const F32 &gamma) const;
 
     LLColor3 getBlueDensity() const;
     LLColor3 getBlueHorizon() const;
diff --git a/indra/newview/lllegacyatmospherics.cpp b/indra/newview/lllegacyatmospherics.cpp
index 9eda254b25..238e9fe0e1 100644
--- a/indra/newview/lllegacyatmospherics.cpp
+++ b/indra/newview/lllegacyatmospherics.cpp
@@ -202,14 +202,8 @@ void LLAtmospherics::init()
 	mInitialized = true;
 }
 
-LLColor4 LLAtmospherics::calcSkyColorInDir(AtmosphericsVars& vars, const LLVector3 &dir, bool isShiny)
-{
-    LLSettingsSky::ptr_t psky = LLEnvironment::instance().getCurrentSky();
-    return calcSkyColorInDir(psky, vars, dir, isShiny);
-}
-
 // This cubemap is used as "environmentMap" in indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
-LLColor4 LLAtmospherics::calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const LLVector3 &dir, bool isShiny)
+LLColor4 LLAtmospherics::calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const LLVector3 &dir, bool isShiny, bool low_end)
 {
 	const F32 sky_saturation = 0.25f;
 	const F32 land_saturation = 0.1f;
@@ -227,7 +221,7 @@ LLColor4 LLAtmospherics::calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, Atm
 		}
 		F32 greyscale_sat = brightness * (1.0f - land_saturation);
 		desat_fog = desat_fog * land_saturation + smear(greyscale_sat);
-		if (!gPipeline.canUseWindLightShaders())
+		if (low_end)
 		{
 			col = LLColor4(desat_fog, 0.f);
 		}
@@ -258,8 +252,7 @@ LLColor4 LLAtmospherics::calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, Atm
 		return LLColor4(sky_color, 0.0f);
 	}
 
-	bool low_end = !gPipeline.canUseWindLightShaders();
-	LLColor3 sky_color = low_end ? vars.hazeColor * 2.0f : psky->gammaCorrect(vars.hazeColor * 2.0f);
+	LLColor3 sky_color = low_end ? vars.hazeColor * 2.0f : psky->gammaCorrect(vars.hazeColor * 2.0f, vars.gamma);
 
 	return LLColor4(sky_color, 0.0f);
 }
@@ -437,12 +430,16 @@ void LLAtmospherics::updateFog(const F32 distance, const LLVector3& tosun_in)
 
     LLSettingsSky::ptr_t psky = LLEnvironment::instance().getCurrentSky();
 
+    // NOTE: This is very similar to LLVOSky::cacheEnvironment()
+    // Differences:
+    //     vars.sun_norm
+    //     vars.sunlight
     // invariants across whole sky tex process...
-    vars.blue_density = psky->getBlueDensity();    
+    vars.blue_density = psky->getBlueDensity();
     vars.blue_horizon = psky->getBlueHorizon();
     vars.haze_density = psky->getHazeDensity();
     vars.haze_horizon = psky->getHazeHorizon();
-    vars.density_multiplier = psky->getDensityMultiplier();    
+    vars.density_multiplier = psky->getDensityMultiplier();
     vars.distance_multiplier = psky->getDistanceMultiplier();
     vars.max_y = psky->getMaxY();
     vars.sun_norm = LLEnvironment::instance().getSunDirectionCFR();
@@ -457,9 +454,9 @@ void LLAtmospherics::updateFog(const F32 distance, const LLVector3& tosun_in)
     vars.total_density = psky->getTotalDensity();
     vars.gamma = psky->getGamma();
 
-	res_color[0] = calcSkyColorInDir(vars, tosun);
-	res_color[1] = calcSkyColorInDir(vars, perp_tosun);
-	res_color[2] = calcSkyColorInDir(vars, tosun_45);
+    res_color[0] = calcSkyColorInDir(psky, vars, tosun);
+    res_color[1] = calcSkyColorInDir(psky, vars, perp_tosun);
+    res_color[2] = calcSkyColorInDir(psky, vars, tosun_45);
 
 	sky_fog_color = color_norm(res_color[0] + res_color[1] + res_color[2]);
 
diff --git a/indra/newview/lllegacyatmospherics.h b/indra/newview/lllegacyatmospherics.h
index 03c8efb91a..d48f3040c3 100644
--- a/indra/newview/lllegacyatmospherics.h
+++ b/indra/newview/lllegacyatmospherics.h
@@ -257,13 +257,11 @@ public:
     void setCloudDensity(F32 cloud_density)          { mCloudDensity = cloud_density; }
     void setWind ( const LLVector3& wind )           { mWind = wind.length(); }
 
-    LLColor4 calcSkyColorInDir(AtmosphericsVars& vars, const LLVector3& dir, bool isShiny = false);
-    LLColor4 calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const LLVector3& dir, bool isShiny = false);
+    LLColor4 calcSkyColorInDir(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const LLVector3& dir, bool isShiny = false, const bool low_end = false);
 
-protected:    
+protected:
 
     void     calcSkyColorWLVert(const LLSettingsSky::ptr_t &psky, LLVector3 & Pn, AtmosphericsVars& vars);
-    LLColor3 getHazeColor(LLSettingsSky::ptr_t psky, AtmosphericsVars& vars, F32 costheta, F32 cloud_shadow);
 
     LLHaze              mHaze;
     F32                 mHazeConcentration;
diff --git a/indra/newview/llsettingsvo.cpp b/indra/newview/llsettingsvo.cpp
index 6a88a8ef2c..0c59de5ea0 100644
--- a/indra/newview/llsettingsvo.cpp
+++ b/indra/newview/llsettingsvo.cpp
@@ -666,6 +666,7 @@ void LLSettingsVOSky::updateSettings()
 
 void LLSettingsVOSky::applySpecial(void *ptarget, bool force)
 {
+    LL_PROFILE_ZONE_SCOPED
     LLVector4 light_direction = LLEnvironment::instance().getClampedLightNorm();
 
     LLShaderUniforms* shader = &((LLShaderUniforms*)ptarget)[LLGLSLShader::SG_DEFAULT];
@@ -908,6 +909,8 @@ LLSD LLSettingsVOWater::convertToLegacy(const LLSettingsWater::ptr_t &pwater)
 //-------------------------------------------------------------------------
 void LLSettingsVOWater::applySpecial(void *ptarget, bool force)
 {
+    LL_PROFILE_ZONE_SCOPED
+
     LLEnvironment& env = LLEnvironment::instance();
 
     auto group = LLGLSLShader::SG_WATER;
diff --git a/indra/newview/llvosky.cpp b/indra/newview/llvosky.cpp
index 1e546861b9..72ec8390a4 100644
--- a/indra/newview/llvosky.cpp
+++ b/indra/newview/llvosky.cpp
@@ -64,7 +64,7 @@ namespace
     const S32 NUM_TILES_X = 8;
     const S32 NUM_TILES_Y = 4;
     const S32 NUM_TILES = NUM_TILES_X * NUM_TILES_Y;
-    const S32 NUM_CUBEMAP_FACES = 6; // See sResolution for face dimensions
+    const S32 NUM_CUBEMAP_FACES = 6; // See SKYTEX_RESOLUTION for face dimensions
     const S32 TOTAL_TILES = NUM_CUBEMAP_FACES * NUM_TILES;
     const S32 MAX_TILES = TOTAL_TILES + 1;
 
@@ -87,8 +87,6 @@ namespace
 		SkyTex
 ***************************************/
 
-S32 LLSkyTex::sComponents = 4;
-S32 LLSkyTex::sResolution = 64;
 S32 LLSkyTex::sCurrent = 0;
 
 
@@ -102,14 +100,14 @@ LLSkyTex::LLSkyTex() :
 void LLSkyTex::init(bool isShiny)
 {
     mIsShiny = isShiny;
-	mSkyData = new LLColor4[sResolution * sResolution];
-	mSkyDirs = new LLVector3[sResolution * sResolution];
+	mSkyData = new LLColor4[SKYTEX_RESOLUTION * SKYTEX_RESOLUTION];
+	mSkyDirs = new LLVector3[SKYTEX_RESOLUTION * SKYTEX_RESOLUTION];
 
 	for (S32 i = 0; i < 2; ++i)
 	{
 		mTexture[i] = LLViewerTextureManager::getLocalTexture(FALSE);
 		mTexture[i]->setAddressMode(LLTexUnit::TAM_CLAMP);
-		mImageRaw[i] = new LLImageRaw(sResolution, sResolution, sComponents);
+		mImageRaw[i] = new LLImageRaw(SKYTEX_RESOLUTION, SKYTEX_RESOLUTION, SKYTEX_COMPONENTS);
 
 		initEmpty(i);
 	}
@@ -141,7 +139,7 @@ LLSkyTex::~LLSkyTex()
 
 S32 LLSkyTex::getResolution()
 {
-    return sResolution;
+    return SKYTEX_RESOLUTION;
 }
 
 S32 LLSkyTex::getCurrent()
@@ -169,12 +167,12 @@ S32 LLSkyTex::getWhich(const BOOL curr)
 void LLSkyTex::initEmpty(const S32 tex)
 {
 	U8* data = mImageRaw[tex]->getData();
-	for (S32 i = 0; i < sResolution; ++i)
+	for (S32 i = 0; i < SKYTEX_RESOLUTION; ++i)
 	{
-		for (S32 j = 0; j < sResolution; ++j)
+		for (S32 j = 0; j < SKYTEX_RESOLUTION; ++j)
 		{
-			const S32 basic_offset = (i * sResolution + j);
-			S32 offset = basic_offset * sComponents;
+			const S32 basic_offset = (i * SKYTEX_RESOLUTION + j);
+			S32 offset = basic_offset * SKYTEX_COMPONENTS;
 			data[offset] = 0;
 			data[offset+1] = 0;
 			data[offset+2] = 0;
@@ -190,12 +188,12 @@ void LLSkyTex::initEmpty(const S32 tex)
 void LLSkyTex::create()
 {
 	U8* data = mImageRaw[sCurrent]->getData();
-	for (S32 i = 0; i < sResolution; ++i)
+	for (S32 i = 0; i < SKYTEX_RESOLUTION; ++i)
 	{
-		for (S32 j = 0; j < sResolution; ++j)
+		for (S32 j = 0; j < SKYTEX_RESOLUTION; ++j)
 		{
-			const S32 basic_offset = (i * sResolution + j);
-			S32 offset = basic_offset * sComponents;
+			const S32 basic_offset = (i * SKYTEX_RESOLUTION + j);
+			S32 offset = basic_offset * SKYTEX_COMPONENTS;
 			U32* pix = (U32*)(data + offset);
 			LLColor4U temp = LLColor4U(mSkyData[basic_offset]);
 			*pix = temp.asRGBA();
@@ -392,10 +390,8 @@ const LLVector3* LLHeavenBody::corners() const
 		Sky
 ***************************************/
 
-
-S32 LLVOSky::sResolution = LLSkyTex::getResolution();
-S32 LLVOSky::sTileResX = sResolution/NUM_TILES_X;
-S32 LLVOSky::sTileResY = sResolution/NUM_TILES_Y;
+const S32 SKYTEX_TILE_RES_X = SKYTEX_RESOLUTION / NUM_TILES_X;
+const S32 SKYTEX_TILE_RES_Y = SKYTEX_RESOLUTION / NUM_TILES_Y;
 
 LLVOSky::LLVOSky(const LLUUID &id, const LLPCode pcode, LLViewerRegion *regionp)
 :	LLStaticViewerObject(id, pcode, regionp, TRUE),
@@ -490,6 +486,7 @@ void LLVOSky::init()
 
 void LLVOSky::cacheEnvironment(LLSettingsSky::ptr_t psky,AtmosphericsVars& atmosphericsVars)
 {
+    // NOTE: Also see: LLAtmospherics::updateFog()
     // invariants across whole sky tex process...
     atmosphericsVars.blue_density = psky->getBlueDensity();
     atmosphericsVars.blue_horizon = psky->getBlueHorizon();
@@ -598,8 +595,8 @@ void LLVOSky::initSkyTextureDirs(const S32 side, const S32 tile)
 	S32 tile_x = tile % NUM_TILES_X;
 	S32 tile_y = tile / NUM_TILES_X;
 
-	S32 tile_x_pos = tile_x * sTileResX;
-	S32 tile_y_pos = tile_y * sTileResY;
+	S32 tile_x_pos = tile_x * SKYTEX_TILE_RES_X;
+	S32 tile_y_pos = tile_y * SKYTEX_TILE_RES_Y;
 
 	F32 coeff[3] = {0, 0, 0};
 	const S32 curr_coef = side >> 1; // 0/1 = Z axis, 2/3 = Y, 4/5 = X
@@ -609,11 +606,11 @@ void LLVOSky::initSkyTextureDirs(const S32 side, const S32 tile)
 
 	coeff[curr_coef] = (F32)side_dir;
 
-	F32 inv_res = 1.f/sResolution;
+	F32 inv_res = 1.f/SKYTEX_RESOLUTION;
 	S32 x, y;
-	for (y = tile_y_pos; y < (tile_y_pos + sTileResY); ++y)
+	for (y = tile_y_pos; y < (tile_y_pos + SKYTEX_TILE_RES_Y); ++y)
 	{
-		for (x = tile_x_pos; x < (tile_x_pos + sTileResX); ++x)
+		for (x = tile_x_pos; x < (tile_x_pos + SKYTEX_TILE_RES_X); ++x)
 		{
 			coeff[x_coef] = F32((x<<1) + 1) * inv_res - 1.f;
 			coeff[y_coef] = F32((y<<1) + 1) * inv_res - 1.f;
@@ -625,21 +622,23 @@ void LLVOSky::initSkyTextureDirs(const S32 side, const S32 tile)
 	}
 }
 
-void LLVOSky::createSkyTexture(LLSettingsSky::ptr_t psky, AtmosphericsVars& vars, const S32 side, const S32 tile)
+void LLVOSky::createSkyTexture(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const S32 side, const S32 tile)
 {
+    const bool low_end = !gPipeline.canUseWindLightShaders();
+
 	S32 tile_x = tile % NUM_TILES_X;
 	S32 tile_y = tile / NUM_TILES_X;
 
-	S32 tile_x_pos = tile_x * sTileResX;
-	S32 tile_y_pos = tile_y * sTileResY;
+	S32 tile_x_pos = tile_x * SKYTEX_TILE_RES_X;
+	S32 tile_y_pos = tile_y * SKYTEX_TILE_RES_Y;
 
 	S32 x, y;
-	for (y = tile_y_pos; y < (tile_y_pos + sTileResY); ++y)
+	for (y = tile_y_pos; y < (tile_y_pos + SKYTEX_TILE_RES_Y); ++y)
 	{
-		for (x = tile_x_pos; x < (tile_x_pos + sTileResX); ++x)
+		for (x = tile_x_pos; x < (tile_x_pos + SKYTEX_TILE_RES_X); ++x)
 		{
-			mSkyTex  [side].setPixel(m_legacyAtmospherics.calcSkyColorInDir(psky, vars, mSkyTex  [side].getDir(x, y), false), x, y);
-			mShinyTex[side].setPixel(m_legacyAtmospherics.calcSkyColorInDir(psky, vars, mShinyTex[side].getDir(x, y), true ), x, y);
+			mSkyTex  [side].setPixel(m_legacyAtmospherics.calcSkyColorInDir(psky, vars, mSkyTex  [side].getDir(x, y), false, low_end), x, y);
+			mShinyTex[side].setPixel(m_legacyAtmospherics.calcSkyColorInDir(psky, vars, mShinyTex[side].getDir(x, y), true , low_end), x, y);
 		}
 	}
 }
diff --git a/indra/newview/llvosky.h b/indra/newview/llvosky.h
index 793dcf4cbf..5941ab6e3b 100644
--- a/indra/newview/llvosky.h
+++ b/indra/newview/llvosky.h
@@ -43,6 +43,9 @@ const F32 HEAVENLY_BODY_DIST	= HORIZON_DIST - 20.f;
 const F32 HEAVENLY_BODY_FACTOR	= 0.1f;
 const F32 HEAVENLY_BODY_SCALE	= HEAVENLY_BODY_DIST * HEAVENLY_BODY_FACTOR;
 
+const F32 SKYTEX_COMPONENTS = 4;
+const F32 SKYTEX_RESOLUTION = 64;
+
 class LLFace;
 class LLHaze;
 
@@ -50,8 +53,6 @@ class LLSkyTex
 {
 	friend class LLVOSky;
 private:
-	static S32		sResolution;
-	static S32		sComponents;
 	LLPointer<LLViewerTexture> mTexture[2];
 	LLPointer<LLImageRaw> mImageRaw[2];
 	LLColor4		*mSkyData;
@@ -82,25 +83,25 @@ protected:
 
 	void setDir(const LLVector3 &dir, const S32 i, const S32 j)
 	{
-		S32 offset = i * sResolution + j;
+		S32 offset = i * SKYTEX_RESOLUTION + j;
 		mSkyDirs[offset] = dir;
 	}
 
 	const LLVector3 &getDir(const S32 i, const S32 j) const
 	{
-		S32 offset = i * sResolution + j;
+		S32 offset = i * SKYTEX_RESOLUTION + j;
 		return mSkyDirs[offset];
 	}
 
 	void setPixel(const LLColor4 &col, const S32 i, const S32 j)
 	{
-		S32 offset = i * sResolution + j;
+		S32 offset = i * SKYTEX_RESOLUTION + j;
 		mSkyData[offset] = col;
 	}
 
 	void setPixel(const LLColor4U &col, const S32 i, const S32 j)
 	{
-		S32 offset = (i * sResolution + j) * sComponents;
+		S32 offset = (i * SKYTEX_RESOLUTION + j) * SKYTEX_COMPONENTS;
 		U32* pix = (U32*) &(mImageRaw[sCurrent]->getData()[offset]);
 		*pix = col.asRGBA();
 	}
@@ -108,7 +109,7 @@ protected:
 	LLColor4U getPixel(const S32 i, const S32 j)
 	{
 		LLColor4U col;
-		S32 offset = (i * sResolution + j) * sComponents;
+		S32 offset = (i * SKYTEX_RESOLUTION + j) * SKYTEX_COMPONENTS;
 		U32* pix = (U32*) &(mImageRaw[sCurrent]->getData()[offset]);
 		col.fromRGBA( *pix );
 		return col;
@@ -300,7 +301,7 @@ protected:
 	void updateDirections(LLSettingsSky::ptr_t psky);
 
 	void initSkyTextureDirs(const S32 side, const S32 tile);
-	void createSkyTexture(LLSettingsSky::ptr_t psky, AtmosphericsVars& vars, const S32 side, const S32 tile);
+	void createSkyTexture(const LLSettingsSky::ptr_t &psky, AtmosphericsVars& vars, const S32 side, const S32 tile);
 
 	LLPointer<LLViewerFetchedTexture> mSunTexturep[2];
 	LLPointer<LLViewerFetchedTexture> mMoonTexturep[2];
diff --git a/indra/newview/llvowlsky.cpp b/indra/newview/llvowlsky.cpp
index 5a8126fa38..d1f584cbca 100644
--- a/indra/newview/llvowlsky.cpp
+++ b/indra/newview/llvowlsky.cpp
@@ -36,8 +36,8 @@
 #include "llenvironment.h"
 #include "llsettingssky.h"
 
-static const U32 MIN_SKY_DETAIL = 8;
-static const U32 MAX_SKY_DETAIL = 180;
+constexpr U32 MIN_SKY_DETAIL = 8;
+constexpr U32 MAX_SKY_DETAIL = 180;
 
 inline U32 LLVOWLSky::getNumStacks(void)
 {
@@ -97,13 +97,14 @@ LLDrawable * LLVOWLSky::createDrawable(LLPipeline * pipeline)
 	return mDrawable;
 }
 
-inline F32 LLVOWLSky::calcPhi(U32 i)
+// a tiny helper function for controlling the sky dome tesselation.
+inline F32 calcPhi(const U32 &i, const F32 &reciprocal_num_stacks)
 {
     // Calc: PI/8 * 1-((1-t^4)*(1-t^4))  { 0<t<1 }
     // Demos: \pi/8*\left(1-((1-x^{4})*(1-x^{4}))\right)\ \left\{0<x\le1\right\}
 
 	// i should range from [0..SKY_STACKS] so t will range from [0.f .. 1.f]
-	F32 t = float(i) / float(getNumStacks());
+	F32 t = float(i) * reciprocal_num_stacks; //SL-16127: remove: / float(getNumStacks());
 
 	// ^4 the parameter of the tesselation to bias things toward 0 (the dome's apex)
 	t *= t;
@@ -187,6 +188,8 @@ BOOL LLVOWLSky::updateGeometry(LLDrawable * drawable)
     }
 
 	{
+        const F32 dome_radius = LLEnvironment::instance().getCurrentSky()->getDomeRadius();
+
 		const U32 max_buffer_bytes = gSavedSettings.getS32("RenderMaxVBOSize")*1024;
 		const U32 data_mask = LLDrawPoolWLSky::SKY_VERTEX_DATA_MASK;
 		const U32 max_verts = max_buffer_bytes / LLVertexBuffer::calcVertexSize(data_mask);
@@ -202,12 +205,14 @@ BOOL LLVOWLSky::updateGeometry(LLDrawable * drawable)
 		// round up to a whole number of segments
 		const U32 strips_segments = (total_stacks+stacks_per_seg-1) / stacks_per_seg;
 
-		LL_INFOS() << "WL Skydome strips in " << strips_segments << " batches." << LL_ENDL;
-
 		mStripsVerts.resize(strips_segments, NULL);
 
+#if RELEASE_SHOW_DEBUG
+		LL_INFOS() << "WL Skydome strips in " << strips_segments << " batches." << LL_ENDL;
+
 		LLTimer timer;
 		timer.start();
+#endif
 
 		for (U32 i = 0; i < strips_segments ;++i)
 		{
@@ -232,34 +237,42 @@ BOOL LLVOWLSky::updateGeometry(LLDrawable * drawable)
 			const U32 num_indices_this_seg = 1+num_stacks_this_seg*(2+2*verts_per_stack);
 			llassert(num_indices_this_seg * sizeof(U16) <= max_buffer_bytes);
 
-			if (!segment->allocateBuffer(num_verts_this_seg, num_indices_this_seg, TRUE))
+			bool allocated = segment->allocateBuffer(num_verts_this_seg, num_indices_this_seg, TRUE);
+#if RELEASE_SHOW_WARNS
+			if( !allocated )
 			{
 				LL_WARNS() << "Failed to allocate Vertex Buffer on update to "
 					<< num_verts_this_seg << " vertices and "
 					<< num_indices_this_seg << " indices" << LL_ENDL;
 			}
+#else
+			(void) allocated;
+#endif
 
 			// lock the buffer
 			BOOL success = segment->getVertexStrider(vertices)
 				&& segment->getTexCoord0Strider(texCoords)
 				&& segment->getIndexStrider(indices);
 
-			if(!success) 
+#if RELEASE_SHOW_DEBUG
+			if(!success)
 			{
 				LL_ERRS() << "Failed updating WindLight sky geometry." << LL_ENDL;
 			}
-
-            U32 vertex_count = 0;
-            U32 index_count  = 0;
+#else
+			(void) success;
+#endif
 
 			// fill it
-			buildStripsBuffer(begin_stack, end_stack, vertex_count, index_count, vertices, texCoords, indices);
+			buildStripsBuffer(begin_stack, end_stack, vertices, texCoords, indices, dome_radius, verts_per_stack, total_stacks);
 
 			// and unlock the buffer
 			segment->flush();
 		}
 	
+#if RELEASE_SHOW_DEBUG
 		LL_INFOS() << "completed in " << llformat("%.2f", timer.getElapsedTimeF32().value()) << "seconds" << LL_ENDL;
+#endif
 	}
 
 	updateStarColors();
@@ -364,23 +377,16 @@ void LLVOWLSky::initStars()
 
 void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
                                   U32 end_stack,
-                                  U32& vertex_count,
-                                  U32& index_count,
-								  LLStrider<LLVector3> & vertices,
-								  LLStrider<LLVector2> & texCoords,
-								  LLStrider<U16> & indices)
+                                  LLStrider<LLVector3> & vertices,
+                                  LLStrider<LLVector2> & texCoords,
+                                  LLStrider<U16> & indices,
+                                  const F32 dome_radius,
+                                  const U32& num_slices,
+                                  const U32& num_stacks)
 {
-    const F32 RADIUS = LLEnvironment::instance().getCurrentSky()->getDomeRadius();
-
-	U32 i, j, num_slices, num_stacks;
+	U32 i, j;
 	F32 phi0, theta, x0, y0, z0;
-
-	// paranoia checking for SL-55986/SL-55833
-	U32 count_verts = 0;
-	U32 count_indices = 0;
-
-	num_slices = getNumSlices();
-	num_stacks = getNumStacks();
+	const F32 reciprocal_num_stacks = 1.f / num_stacks;
 
 	llassert(end_stack <= num_stacks);
 
@@ -391,7 +397,7 @@ void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
     for(i = begin_stack + 1; i <= end_stack+1; ++i) 
 #endif
 	{
-		phi0 = calcPhi(i);
+		phi0 = calcPhi(i, reciprocal_num_stacks);
 
 		for(j = 0; j < num_slices; ++j)
 		{
@@ -404,24 +410,22 @@ void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
 			z0 = sin(phi0) * sin(theta);
 
 #if NEW_TESS
-            *vertices++ = LLVector3(x0 * RADIUS, y0 * RADIUS, z0 * RADIUS);
+            *vertices++ = LLVector3(x0 * dome_radius, y0 * dome_radius, z0 * dome_radius);
 #else
             if (i == num_stacks-2)
 			{
-				*vertices++ = LLVector3(x0*RADIUS, y0*RADIUS-1024.f*2.f, z0*RADIUS);
+				*vertices++ = LLVector3(x0*dome_radius, y0*dome_radius-1024.f*2.f, z0*dome_radius);
 			}
 			else if (i == num_stacks-1)
 			{
-				*vertices++ = LLVector3(0, y0*RADIUS-1024.f*2.f, 0);
+				*vertices++ = LLVector3(0, y0*dome_radius-1024.f*2.f, 0);
 			}
 			else
 			{
-				*vertices++		= LLVector3(x0 * RADIUS, y0 * RADIUS, z0 * RADIUS);
+				*vertices++		= LLVector3(x0 * dome_radius, y0 * dome_radius, z0 * dome_radius);
 			}
 #endif
 
-			++count_verts;
-
 			// generate planar uv coordinates
 			// note: x and z are transposed in order for things to animate
 			// correctly in the global coordinate system where +x is east and
@@ -432,12 +436,11 @@ void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
 
 	//build triangle strip...
 	*indices++ = 0 ;
-	count_indices++ ;
+
 	S32 k = 0 ;
 	for(i = 1; i <= end_stack - begin_stack; ++i) 
 	{
 		*indices++ = i * num_slices + k ;
-		count_indices++ ;
 
 		k = (k+1) % num_slices ;
 		for(j = 0; j < num_slices ; ++j) 
@@ -445,8 +448,6 @@ void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
 			*indices++ = (i-1) * num_slices + k ;
 			*indices++ = i * num_slices + k ;
 
-			count_indices += 2 ;
-
 			k = (k+1) % num_slices ;
 		}
 
@@ -456,11 +457,7 @@ void LLVOWLSky::buildStripsBuffer(U32 begin_stack,
 		}
 
 		*indices++ = i * num_slices + k ;
-		count_indices++ ;
 	}
-
-    vertex_count = count_verts;
-    index_count = count_indices;
 }
 
 void LLVOWLSky::updateStarColors()
diff --git a/indra/newview/llvowlsky.h b/indra/newview/llvowlsky.h
index 2b7ebe75dd..3853dd2c70 100644
--- a/indra/newview/llvowlsky.h
+++ b/indra/newview/llvowlsky.h
@@ -55,8 +55,6 @@ public:
 	void restoreGL();
 
 private:
-	// a tiny helper function for controlling the sky dome tesselation.
-	static F32 calcPhi(U32 i);
 
 	// helper function for initializing the stars.
 	void initStars();
@@ -66,11 +64,12 @@ private:
 	// begin_stack is the first stack to be included, end_stack is the first
 	// stack not to be included.
 	static void buildStripsBuffer(U32 begin_stack, U32 end_stack,
-                                  U32& vertex_count,
-                                  U32& index_count,
-								  LLStrider<LLVector3> & vertices,
-								  LLStrider<LLVector2> & texCoords,
-								  LLStrider<U16> & indices);
+                                  LLStrider<LLVector3> & vertices,
+                                  LLStrider<LLVector2> & texCoords,
+                                  LLStrider<U16> & indices,
+                                  const F32 RADIUS,
+                                  const U32& num_slices,
+                                  const U32& num_stacks);
 
 	// helper function for updating the stars colors.
 	void updateStarColors();