"Fixed" the long-time weird rendering artifacts that are apparently caused by vertex coordinates not being integers.

A better fix would be to move to OpenGL 3/GLES 2 and do rounding in the shader.  But I don't have time for that.

DEVNOTES.md

@@ -33,3 +33,13 @@ Creating a new GameListView Class
 =================================
 
 1. Don't allow the user to navigate to the root node's parent. If you use a stack of some sort to keep track of past cursor states this will be a natural side effect.
+
+
+
+Creating a new Component
+========================
+
+If your component is not made up of other components, and you draw something to the screen with OpenGL, make sure:
+
+* Your vertex positions are rounded before you render (you can use round(float) in Util.h to do this).
+* Your transform matrix's translation is rounded (you can use roundMatrix(affine3f) in Util.h to do this).

src/Renderer.h

@@ -38,6 +38,7 @@ namespace Renderer
 	void setMatrix(const Eigen::Affine3f& transform);
 
 	void drawRect(int x, int y, int w, int h, unsigned int color, GLenum blend_sfactor = GL_SRC_ALPHA, GLenum blend_dfactor = GL_ONE_MINUS_SRC_ALPHA);
+	void drawRect(float x, float y, float w, float h, unsigned int color, GLenum blend_sfactor = GL_SRC_ALPHA, GLenum blend_dfactor = GL_ONE_MINUS_SRC_ALPHA);
 }
 
 #endif

src/Renderer_draw_gl.cpp

@@ -6,6 +6,7 @@
 #include <boost/filesystem.hpp>
 #include "Log.h"
 #include <stack>
+#include "Util.h"
 
 namespace Renderer {
 	std::stack<Eigen::Vector4i> clipStack;
@@ -87,6 +88,11 @@ namespace Renderer {
 		}
 	}
 
+	void drawRect(float x, float y, float w, float h, unsigned int color, GLenum blend_sfactor, GLenum blend_dfactor)
+	{
+		drawRect((int)round(x), (int)round(y), (int)round(w), (int)round(h), color, blend_sfactor, blend_dfactor);
+	}
+
 	void drawRect(int x, int y, int w, int h, unsigned int color, GLenum blend_sfactor, GLenum blend_dfactor)
 	{
 #ifdef USE_OPENGL_ES

src/Renderer_init_sdlgl.cpp

@@ -43,6 +43,10 @@ namespace Renderer
 		SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);
 		SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 
+		// multisample anti-aliasing
+		//SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
+		//SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 2);
+
 #ifdef USE_OPENGL_ES
 		SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 1);
 #endif
@@ -91,12 +95,6 @@ namespace Renderer
 
 		sdlContext = SDL_GL_CreateContext(sdlWindow);
 
-		//usually display width/height are not specified, i.e. zero, which SDL automatically takes as "native resolution"
-		//so, since other things rely on the size of the screen (damn currently unnormalized coordinate system), we set it here
-		//even though the system was already initialized - this makes sure it gets reinitialized to the original resolution when we return from a game
-		//display_width = sdlWindow->w;
-		//display_height = sdlWindow->h;
-
 		//hide mouse cursor
 		initialCursorState = SDL_ShowCursor(0) == 1;
 

src/Util.cpp

@@ -20,3 +20,39 @@ std::string strToUpper(const std::string& str)
 {
 	return strToUpper(str.c_str());
 }
+
+float round(float num)
+{
+	return (float)((int)(num + 0.5f));
+}
+
+Eigen::Affine3f& roundMatrix(Eigen::Affine3f& mat)
+{
+	mat.translation()[0] = round(mat.translation()[0]);
+	mat.translation()[1] = round(mat.translation()[1]);
+	return mat;
+}
+
+Eigen::Affine3f roundMatrix(const Eigen::Affine3f& mat)
+{
+	Eigen::Affine3f ret = mat;
+	roundMatrix(ret);
+	return ret;
+}
+
+Eigen::Vector3f roundVector(const Eigen::Vector3f& vec)
+{
+	Eigen::Vector3f ret = vec;
+	ret[0] = round(ret[0]);
+	ret[1] = round(ret[1]);
+	ret[2] = round(ret[2]);
+	return ret;
+}
+
+Eigen::Vector2f roundVector(const Eigen::Vector2f& vec)
+{
+	Eigen::Vector2f ret = vec;
+	ret[0] = round(ret[0]);
+	ret[1] = round(ret[1]);
+	return ret;
+}

src/Util.h

@@ -1,5 +1,14 @@
 #include <string>
+#include <Eigen/Dense>
 
 std::string strToUpper(const char* from);
 std::string& strToUpper(std::string& str);
 std::string strToUpper(const std::string& str);
+
+Eigen::Affine3f& roundMatrix(Eigen::Affine3f& mat);
+Eigen::Affine3f roundMatrix(const Eigen::Affine3f& mat);
+
+Eigen::Vector3f roundVector(const Eigen::Vector3f& vec);
+Eigen::Vector2f roundVector(const Eigen::Vector2f& vec);
+
+float round(float num);

src/components/ButtonComponent.cpp

@@ -85,13 +85,14 @@ void ButtonComponent::updateImage()
 
 void ButtonComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 	
 	mBox.render(trans);
 
 	if(mTextCache)
 	{
 		Eigen::Vector3f centerOffset((mSize.x() - mTextCache->metrics.size.x()) / 2, (mSize.y() - mTextCache->metrics.size.y()) / 2, 0);
+		centerOffset = roundVector(centerOffset);
 		trans = trans.translate(centerOffset);
 
 		Renderer::setMatrix(trans);

src/components/ComponentList.cpp

@@ -1,4 +1,5 @@
 #include "ComponentList.h"
+#include "../Util.h"
 
 #define TOTAL_HORIZONTAL_PADDING_PX 20
 
@@ -128,16 +129,16 @@ void ComponentList::render(const Eigen::Affine3f& parentTrans)
 	if(!size())
 		return;
 
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 
 	// clip everything to be inside our bounds
 	Eigen::Vector3f dim(mSize.x(), mSize.y(), 0);
 	dim = trans * dim - trans.translation();
-	Renderer::pushClipRect(Eigen::Vector2i((int)trans.translation().x(), 
+	Renderer::pushClipRect(Eigen::Vector2i((int)trans.translation().x(), (int)trans.translation().y()), 
-		(int)trans.translation().y()), Eigen::Vector2i((int)dim.x(), (int)dim.y()));
+		Eigen::Vector2i((int)round(dim.x()), (int)round(dim.y())));
 
 	// scroll the camera
-	trans.translate(Eigen::Vector3f(0, -mCameraOffset, 0));
+	trans.translate(Eigen::Vector3f(0, -round(mCameraOffset), 0));
 
 	// draw our entries
 	renderChildren(trans);
@@ -154,24 +155,24 @@ void ComponentList::render(const Eigen::Affine3f& parentTrans)
 		// (1 - dst) + 0x77
 	
 		const float selectedRowHeight = getRowHeight(mEntries.at(mCursor).data);
-		Renderer::drawRect(0, (int)mSelectorBarOffset, (int)mSize.x(), (int)selectedRowHeight, 0xFFFFFFFF,
+		Renderer::drawRect(0.0f, mSelectorBarOffset, mSize.x(), selectedRowHeight, 0xFFFFFFFF,
 			GL_ONE_MINUS_DST_COLOR, GL_ZERO);
-		Renderer::drawRect(0, (int)mSelectorBarOffset, (int)mSize.x(), (int)selectedRowHeight, 0x777777FF,
+		Renderer::drawRect(0.0f, mSelectorBarOffset, mSize.x(), selectedRowHeight, 0x777777FF,
 			GL_ONE, GL_ONE);
 	
 		// hack to draw 2px dark on left/right of the bar
-		Renderer::drawRect(0, (int)mSelectorBarOffset, 2, (int)selectedRowHeight, 0x878787FF);
+		Renderer::drawRect(0.0f, mSelectorBarOffset, 2.0f, selectedRowHeight, 0x878787FF);
-		Renderer::drawRect((int)mSize.x() - 2, (int)mSelectorBarOffset, 2, (int)selectedRowHeight, 0x878787FF);
+		Renderer::drawRect(mSize.x() - 2.0f, mSelectorBarOffset, 2.0f, selectedRowHeight, 0x878787FF);
 	}
 
 	// draw separators
 	float y = 0;
 	for(unsigned int i = 0; i < mEntries.size(); i++)
 	{
-		Renderer::drawRect(0, (int)y, (int)mSize.x(), 1, 0xC6C7C6FF);
+		Renderer::drawRect(0.0f, y, mSize.x(), 1.0f, 0xC6C7C6FF);
 		y += getRowHeight(mEntries.at(i).data);
 	}
-	Renderer::drawRect(0, (int)y, (int)mSize.x(), 1, 0xC6C7C6FF);
+	Renderer::drawRect(0.0f, y, mSize.x(), 1.0f, 0xC6C7C6FF);
 
 	Renderer::popClipRect();
 }

src/components/DateTimeComponent.cpp

@@ -3,6 +3,7 @@
 #include "../Renderer.h"
 #include "../Window.h"
 #include "../Log.h"
+#include "../Util.h"
 
 DateTimeComponent::DateTimeComponent(Window* window) : GuiComponent(window), 
 	mEditing(false), mEditIndex(0), mDisplayMode(DISP_DATE), mRelativeUpdateAccumulator(0), 
@@ -136,7 +137,7 @@ void DateTimeComponent::update(int deltaTime)
 
 void DateTimeComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 	Renderer::setMatrix(trans);
 
 	if(mTextCache)

src/components/ImageComponent.cpp

@@ -5,6 +5,7 @@
 #include "../Log.h"
 #include "../Renderer.h"
 #include "../ThemeData.h"
+#include "../Util.h"
 
 Eigen::Vector2i ImageComponent::getTextureSize() const
 {
@@ -136,7 +137,7 @@ void ImageComponent::setColorShift(unsigned int color)
 
 void ImageComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 	Renderer::setMatrix(trans);
 	
 	if(mTexture && getOpacity() > 0)
@@ -172,6 +173,9 @@ void ImageComponent::buildImageArray(int posX, int posY, GLfloat* points, GLfloa
 	points[8] = posX - (mSize.x() * mOrigin.x());		points[9] = posY + (mSize.y() * (1 - mOrigin.y()));
 	points[10] = posX + (mSize.x() * (1 -mOrigin.x()));		points[11] = posY + (mSize.y() * (1 - mOrigin.y()));
 
+	// round vertices
+	for(int i = 0; i < 12; i++)
+		points[i] = round(points[i]);
 
 
 	texs[0] = 0;		texs[1] = py;

src/components/NinePatchComponent.cpp

@@ -3,6 +3,7 @@
 #include "../Log.h"
 #include "../Renderer.h"
 #include "../ThemeData.h"
+#include "../Util.h"
 
 NinePatchComponent::NinePatchComponent(Window* window, const std::string& path, unsigned int edgeColor, unsigned int centerColor) : GuiComponent(window),
 	mEdgeColor(edgeColor), mCenterColor(centerColor), 
@@ -121,11 +122,18 @@ void NinePatchComponent::buildVertices()
 
 		v += 6;
 	}
+
+	// round vertices
+	for(int i = 0; i < 6*9; i++)
+	{
+		mVertices[i].pos = roundVector(mVertices[i].pos);
+	}
 }
 
 void NinePatchComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
+	
 	if(mTexture && mVertices != NULL)
 	{
 		Renderer::setMatrix(trans);

src/components/RatingComponent.cpp

@@ -1,6 +1,7 @@
 #include "RatingComponent.h"
 #include "../Renderer.h"
 #include "../Window.h"
+#include "../Util.h"
 
 RatingComponent::RatingComponent(Window* window) : GuiComponent(window)
 {
@@ -71,11 +72,14 @@ void RatingComponent::updateVertices()
 	mVertices[10].pos << fw, 0.0f;
 		mVertices[10].tex << numStars, 1.0f;
 	mVertices[11] = mVertices[7];
+
+	for(int i = 0; i < 12; i++)
+		mVertices[i].pos = roundVector(mVertices[i].pos);
 }
 
 void RatingComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 	Renderer::setMatrix(trans);
 
 	glEnable(GL_TEXTURE_2D);

src/components/SliderComponent.cpp

@@ -3,6 +3,7 @@
 #include "../Renderer.h"
 #include "../resources/Font.h"
 #include "../Log.h"
+#include "../Util.h"
 
 SliderComponent::SliderComponent(Window* window, float min, float max, float increment, const std::string& suffix) : GuiComponent(window),
 	mMin(min), mMax(max), mIncrement(increment), mMoveRate(0), mRepeatWaitTimer(0), mKnob(window), mSuffix(suffix)
@@ -74,7 +75,7 @@ void SliderComponent::update(int deltaTime)
 
 void SliderComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 	Renderer::setMatrix(trans);
 
 	// render suffix
@@ -84,8 +85,8 @@ void SliderComponent::render(const Eigen::Affine3f& parentTrans)
 	float width = mSize.x() - mKnob.getSize().x() - (mValueCache ? mValueCache->metrics.size.x() + 4 : 0);
 
 	//render line
-	const int lineWidth = 2;
+	const float lineWidth = 2;
-	Renderer::drawRect((int)mKnob.getSize().x() / 2, (int)mSize.y() / 2 - lineWidth / 2, (int)width, lineWidth, 0x777777FF);
+	Renderer::drawRect(mKnob.getSize().x() / 2, mSize.y() / 2 - lineWidth / 2, width, lineWidth, 0x777777FF);
 
 	//render knob
 	mKnob.render(trans);

src/components/TextComponent.cpp

@@ -3,6 +3,7 @@
 #include "../Log.h"
 #include "../Window.h"
 #include "../ThemeData.h"
+#include "../Util.h"
 
 TextComponent::TextComponent(Window* window) : GuiComponent(window), 
 	mFont(Font::get(FONT_SIZE_MEDIUM)), mColor(0x000000FF), mAutoCalcExtent(true, true), mCentered(false)
@@ -68,11 +69,12 @@ void TextComponent::setCentered(bool center)
 
 void TextComponent::render(const Eigen::Affine3f& parentTrans)
 {
-	Eigen::Affine3f trans = parentTrans * getTransform();
+	Eigen::Affine3f trans = roundMatrix(parentTrans * getTransform());
 
 	Eigen::Vector3f dim(mSize.x(), mSize.y(), 0);
 	dim = trans * dim - trans.translation();
-	Renderer::pushClipRect(Eigen::Vector2i((int)trans.translation().x(), (int)trans.translation().y()), Eigen::Vector2i((int)dim.x(), (int)dim.y()));
+	Renderer::pushClipRect(Eigen::Vector2i((int)trans.translation().x(), (int)trans.translation().y()), 
+		Eigen::Vector2i((int)(dim.x() + 0.5f), (int)(dim.y() + 0.5f)));
 
 	if(mTextCache)
 	{
@@ -80,6 +82,7 @@ void TextComponent::render(const Eigen::Affine3f& parentTrans)
 		{
 			const Eigen::Vector2f& textSize = mTextCache->metrics.size;
 			Eigen::Vector3f off((getSize().x() - textSize.x()) / 2, (getSize().y() - textSize.y()) / 2, 0);
+			off = roundVector(off);
 
 			trans.translate(off);
 			Renderer::setMatrix(trans);

src/resources/Font.cpp

@@ -5,6 +5,7 @@
 #include "../Renderer.h"
 #include <boost/filesystem.hpp>
 #include "../Log.h"
+#include "../Util.h"
 
 FT_Library Font::sLibrary;
 bool Font::libraryInitialized = false;
@@ -475,6 +476,12 @@ TextCache* Font::buildTextCache(const std::string& text, float offsetX, float of
 		vert[i + 5].tex[0] = vert[i + 1].tex.x();
 		vert[i + 5].tex[1] = vert[i + 0].tex.y();
 
+		// round
+		for(int j = 0; j < 6; j++)
+		{
+			vert[i + j].pos = roundVector(vert[i + j].pos);
+		}
+
 		x += charData[letter].advX * fontScale;
 	}