From 4e5c1ce49e320dd5e1e8b979adce654d5cc49185 Mon Sep 17 00:00:00 2001
From: pjft <paulo.j.tavares@gmail.com>
Date: Wed, 17 May 2017 13:01:15 +0100
Subject: [PATCH] Changes to mitigate white flashes ES navigation

- Set default GL clear color to black, rather than white
- Revert changes to ImageComponent intialization that cause white flashes
- Increased ALSA buffer to prevent buffer underruns which stall CPU momentarily
- Improved carousel texture buffering based on navigation direction and speed
---
 es-app/src/views/SystemView.cpp     | 21 ++++++++++++++++-----
 es-core/src/AudioManager.cpp        |  2 +-
 es-core/src/Renderer_init_sdlgl.cpp |  2 +-
 es-core/src/components/IList.h      |  7 ++++++-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/es-app/src/views/SystemView.cpp b/es-app/src/views/SystemView.cpp
index 9794ea91a..06668796a 100644
--- a/es-app/src/views/SystemView.cpp
+++ b/es-app/src/views/SystemView.cpp
@@ -9,6 +9,10 @@
 #include "Settings.h"
 #include "Util.h"
 
+// buffer values for scrolling velocity (left, stopped, right)
+const int logoBuffersLeft[] = { -5, -2, -1 };
+const int logoBuffersRight[] = { 1, 2, 5 };
+
 SystemView::SystemView(Window* window) : IList<SystemViewData, SystemData*>(window, LIST_SCROLL_STYLE_SLOW, LIST_ALWAYS_LOOP),
 										 mViewNeedsReload(true),
 										 mSystemInfo(window, "SYSTEM INFO", Font::get(FONT_SIZE_SMALL), 0x33333300, ALIGN_CENTER)
@@ -39,14 +43,14 @@ void SystemView::populate()
 		// make logo
 		if(theme->getElement("system", "logo", "image"))
 		{
-			ImageComponent* logo = new ImageComponent(mWindow);
+			ImageComponent* logo = new ImageComponent(mWindow, false, false);
 			logo->setMaxSize(Eigen::Vector2f(mCarousel.logoSize.x(), mCarousel.logoSize.y()));
 			logo->applyTheme((*it)->getTheme(), "system", "logo", ThemeFlags::PATH);
 			logo->setPosition((mCarousel.logoSize.x() - logo->getSize().x()) / 2,
 				(mCarousel.logoSize.y() - logo->getSize().y()) / 2); // center
 			e.data.logo = std::shared_ptr<GuiComponent>(logo);
 
-			ImageComponent* logoSelected = new ImageComponent(mWindow);
+			ImageComponent* logoSelected = new ImageComponent(mWindow, false, false);
 			logoSelected->setMaxSize(Eigen::Vector2f(mCarousel.logoSize.x() * mCarousel.logoScale, mCarousel.logoSize.y() * mCarousel.logoScale));
 			logoSelected->applyTheme((*it)->getTheme(), "system", "logo", ThemeFlags::PATH | ThemeFlags::COLOR);
 			logoSelected->setPosition((mCarousel.logoSize.x() - logoSelected->getSize().x()) / 2,
@@ -364,9 +368,12 @@ void SystemView::renderCarousel(const Eigen::Affine3f& trans)
 
 	Eigen::Affine3f logoTrans = trans;
 	int center = (int)(mCamOffset);
-	int logoCount = std::min(mCarousel.maxLogoCount, (int)mEntries.size()) + 2;
+	int logoCount = std::min(mCarousel.maxLogoCount, (int)mEntries.size());
 
-	for (int i = center - logoCount / 2; i < center + logoCount / 2 + 1; i++)
+	// Adding texture loading buffers depending on scrolling speed and status	
+	int bufferIndex = getScrollingVelocity() + 1;	
+	
+	for (int i = center - logoCount / 2 + logoBuffersLeft[bufferIndex]; i <= center + logoCount / 2 + logoBuffersRight[bufferIndex]; i++)
 	{
 		int index = i;
 		while (index < 0)
@@ -402,7 +409,11 @@ void SystemView::renderExtras(const Eigen::Affine3f& trans)
 {
 	Eigen::Affine3f extrasTrans = trans;
 	int extrasCenter = (int)mExtrasCamOffset;
-	for (int i = extrasCenter - 1; i < extrasCenter + 2; i++)
+	
+	// Adding texture loading buffers depending on scrolling speed and status
+	int bufferIndex = getScrollingVelocity() + 1;
+	
+	for (int i = extrasCenter + logoBuffersLeft[bufferIndex]; i <= extrasCenter + logoBuffersRight[bufferIndex]; i++)
 	{
 		int index = i;
 		while (index < 0)
diff --git a/es-core/src/AudioManager.cpp b/es-core/src/AudioManager.cpp
index c75d3c4ca..cbc0821ed 100644
--- a/es-core/src/AudioManager.cpp
+++ b/es-core/src/AudioManager.cpp
@@ -89,7 +89,7 @@ void AudioManager::init()
 	sAudioFormat.freq = 44100;
 	sAudioFormat.format = AUDIO_S16;
 	sAudioFormat.channels = 2;
-	sAudioFormat.samples = 1024;
+	sAudioFormat.samples = 4096;
 	sAudioFormat.callback = mixAudio;
 	sAudioFormat.userdata = NULL;
 
diff --git a/es-core/src/Renderer_init_sdlgl.cpp b/es-core/src/Renderer_init_sdlgl.cpp
index ab0bfb56a..b34e06664 100644
--- a/es-core/src/Renderer_init_sdlgl.cpp
+++ b/es-core/src/Renderer_init_sdlgl.cpp
@@ -151,7 +151,7 @@ namespace Renderer
 		glMatrixMode(GL_PROJECTION);
 		glOrtho(0, display_width, display_height, 0, -1.0, 1.0);
 		glMatrixMode(GL_MODELVIEW);
-		glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
+		glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 
 		return true;
 	}
diff --git a/es-core/src/components/IList.h b/es-core/src/components/IList.h
index ede3360a9..5543fae06 100644
--- a/es-core/src/components/IList.h
+++ b/es-core/src/components/IList.h
@@ -44,7 +44,7 @@ const ScrollTierList LIST_SCROLL_STYLE_QUICK = { 4, QUICK_SCROLL_TIERS };
 
 const ScrollTier SLOW_SCROLL_TIERS[] = {
 	{500, 500},
-	{0, 150}
+	{0, 200}
 };
 const ScrollTierList LIST_SCROLL_STYLE_SLOW = { 2, SLOW_SCROLL_TIERS };
 
@@ -100,6 +100,11 @@ public:
 		return (mScrollVelocity != 0 && mScrollTier > 0);
 	}
 
+	int getScrollingVelocity() 
+	{
+		return mScrollVelocity;
+	}
+
 	void stopScrolling()
 	{
 		listInput(0);