diff -r 4c134708be05 -r 2f18c0da749d src/vertexcompiler.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/vertexcompiler.cpp	Fri Apr 27 16:27:14 2018 +0300
@@ -0,0 +1,267 @@
+/*
+ *  LDForge: LDraw parts authoring CAD
+ *  Copyright (C) 2013 - 2018 Teemu Piippo
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "vertexcompiler.h"
+#include "vertexselection.h"
+#include "model.h"
+
+static const Vertex sphere[] = {
+	{1, 0, 0}, {0.7071, 0.7071, 0}, {0.7071, 0, 0.7071},
+	{0, 0.7071, 0.7071}, {0, 0, 1}, {0.7071, 0, 0.7071},
+	{0.7071, 0.7071, 0}, {0, 0.7071, 0.7071}, {0.7071, 0, 0.7071},
+	{0, 1, 0}, {0, 0.7071, 0.7071}, {0.7071, 0.7071, 0},
+	{0.7071, 0, -0.7071}, {0.7071, 0.7071, 0}, {1, 0, 0},
+	{0.7071, 0, -0.7071}, {0, 0, -1}, {0, 0.7071, -0.7071},
+	{0.7071, 0, -0.7071}, {0, 0.7071, -0.7071}, {0.7071, 0.7071, 0},
+	{0.7071, 0.7071, 0}, {0, 0.7071, -0.7071}, {0, 1, 0},
+	{-0.7071, 0, 0.7071}, {-0.7071, 0.7071, 0}, {-1, 0, 0},
+	{-0.7071, 0, 0.7071}, {0, 0, 1}, {0, 0.7071, 0.7071},
+	{-0.7071, 0, 0.7071}, {0, 0.7071, 0.7071}, {-0.7071, 0.7071, 0},
+	{-0.7071, 0.7071, 0}, {0, 0.7071, 0.7071}, {0, 1, 0},
+	{-1, 0, 0}, {-0.7071, 0.7071, 0}, {-0.7071, 0, -0.7071},
+	{0, 0.7071, -0.7071}, {0, 0, -1}, {-0.7071, 0, -0.7071},
+	{-0.7071, 0.7071, 0}, {0, 0.7071, -0.7071}, {-0.7071, 0, -0.7071},
+	{0, 1, 0}, {0, 0.7071, -0.7071}, {-0.7071, 0.7071, 0},
+	{-0.7071, 0, -0.7071}, {0, 0, -1}, {0, -0.7071, -0.7071},
+	{0, -1, 0}, {0, -0.7071, 0.7071}, {-0.7071, -0.7071, 0},
+	{0.7071, -0.7071, 0}, {0, -0.7071, -0.7071}, {0.7071, 0, -0.7071},
+	{-1, 0, 0}, {-0.7071, -0.7071, 0}, {-0.7071, 0, 0.7071},
+	{-0.7071, -0.7071, 0}, {0, -0.7071, -0.7071}, {0, -1, 0},
+	{0, -1, 0}, {0, -0.7071, -0.7071}, {0.7071, -0.7071, 0},
+	{0.7071, 0, 0.7071}, {0, -0.7071, 0.7071}, {0.7071, -0.7071, 0},
+	{-0.7071, 0, -0.7071}, {-0.7071, -0.7071, 0}, {-1, 0, 0},
+	{1, 0, 0}, {0.7071, -0.7071, 0}, {0.7071, 0, -0.7071},
+	{0.7071, 0, 0.7071}, {0, 0, 1}, {0, -0.7071, 0.7071},
+	{-0.7071, 0, -0.7071}, {0, -0.7071, -0.7071}, {-0.7071, -0.7071, 0},
+	{0.7071, -0.7071, 0}, {0, -0.7071, 0.7071}, {0, -1, 0},
+	{0.7071, 0, 0.7071}, {0.7071, -0.7071, 0}, {1, 0, 0},
+	{-0.7071, -0.7071, 0}, {0, -0.7071, 0.7071}, {-0.7071, 0, 0.7071},
+	{0, -0.7071, -0.7071}, {0, 0, -1}, {0.7071, 0, -0.7071},
+	{0, -0.7071, 0.7071}, {0, 0, 1}, {-0.7071, 0, 0.7071},
+};
+
+static const float sphereSize = 0.5;
+static const QColor sphereColor {192, 192, 255};
+
+VertexCompiler::VertexCompiler(Model* model, VertexSelection* selection, QObject* parent) :
+	QObject {parent},
+	model {model}
+{
+	connect(model, &Model::objectAdded, this, &VertexCompiler::handleNewObject);
+	connect(model, &Model::aboutToRemoveObject, this, &VertexCompiler::handleRemovedObject);
+
+	if (selection != nullptr)
+	{
+		this->connect(
+			selection,
+			&VertexSelection::vertexSelected,
+			this,
+			&VertexCompiler::updateVertex
+		);
+		this->connect(
+			selection,
+			&VertexSelection::vertexDeselected,
+			this,
+			&VertexCompiler::updateVertex
+		);
+	}
+}
+
+VertexCompiler::~VertexCompiler()
+{
+	if (this->initialized)
+	{
+		GLuint buffers[NumVbos];
+
+		for (int i = 0; i < countof(this->vbos); i += 1)
+			buffers[i] = this->vbos[i].buffer;
+
+		this->glDeleteBuffers(countof(buffers), &buffers[0]);
+	}
+}
+
+void VertexCompiler::handleNewObject(const QModelIndex &index)
+{
+	LDObject* object = this->model->lookup(index);
+	this->addVerticesFromObject(object);
+	connect(object, &LDObject::aboutToBeModified, this, &VertexCompiler::handlePreModifiedObject);
+	connect(object, &LDObject::modified, this, &VertexCompiler::handleModifiedObject);
+}
+
+void VertexCompiler::handleRemovedObject(const QModelIndex &index)
+{
+	LDObject* object = this->model->lookup(index);
+	this->removeVerticesFromObject(object);
+}
+
+void VertexCompiler::handlePreModifiedObject()
+{
+	removeVerticesFromObject(qobject_cast<LDObject*>(this->sender()));
+}
+
+void VertexCompiler::handleModifiedObject()
+{
+	addVerticesFromObject(qobject_cast<LDObject*>(this->sender()));
+}
+
+void VertexCompiler::initialize()
+{
+	if (not this->initialized)
+	{
+		this->initializeOpenGLFunctions();
+		this->initialized = true;
+		GLuint buffers[NumVbos];
+		this->glGenBuffers(countof(buffers), &buffers[0]);
+
+		for (int i = 0; i < countof(this->vbos); i += 1)
+			this->vbos[i].buffer = buffers[i];
+	}
+}
+
+void VertexCompiler::addVerticesFromObject(LDObject* object)
+{
+	for (int i = 0; i < object->numPolygonVertices(); i += 1)
+		this->addVertex(object->vertex(i));
+
+	this->needCompile = true;
+}
+
+void VertexCompiler::removeVerticesFromObject(LDObject* object)
+{
+	for (int i = 0; i < object->numPolygonVertices(); i += 1)
+		this->removeVertex(object->vertex(i));
+
+	this->needCompile = true;
+}
+
+void VertexCompiler::addVertex(const Vertex& vertex)
+{
+	auto iterator = this->vertices.find(vertex);
+
+	if (iterator == this->vertices.end())
+		this->vertices.insert(vertex, 1);
+	else
+		iterator.value() += 1;
+}
+
+void VertexCompiler::removeVertex(const Vertex& vertex)
+{
+	auto iterator = this->vertices.find(vertex);
+
+	if (iterator != this->vertices.end())
+	{
+		if (iterator.value() > 1)
+			iterator.value() -= 1;
+		else
+			this->vertices.erase(iterator);
+	}
+}
+
+void VertexCompiler::updateVertex(const Vertex&)
+{
+	this->needCompile = true;
+}
+
+/*
+ * Returns the GL buffer for the given vbo.
+ */
+GLuint VertexCompiler::vbo(Vbo vboIndex)
+{
+	if (this->needCompile)
+	{
+		this->compile();
+		this->upload();
+		this->needCompile = false;
+	}
+
+	return this->vbos[vboIndex].buffer;
+}
+
+/*
+ * Returns the size of the given vbo.
+ */
+size_t VertexCompiler::vboSize(Vbo vboIndex) const
+{
+	return this->vbos[vboIndex].data.size();
+}
+
+/*
+ * Clears the vertex scene.
+ */
+void VertexCompiler::clear()
+{
+	for (auto& vbo : this->vbos)
+		vbo.data.clear();
+}
+
+/*
+ * Builds the vertex scene
+ */
+void VertexCompiler::compile()
+{
+	this->clear();
+	QMapIterator<Vertex, unsigned int> iterator {this->vertices};
+
+	while (iterator.hasNext())
+	{
+		iterator.next();
+		this->compileVertex(iterator.key());
+	}
+}
+
+/*
+ * Adds a little sphere into the scene to represent the given vertex.
+ */
+void VertexCompiler::compileVertex(const Vertex& vertex)
+{
+	for (int i = 0; i < countof(::sphere); i += 1)
+	{
+		// Y and Z inverted like the rest of the scene
+		Vertex spherePoint = {
+			::sphere[i][X] * ::sphereSize + vertex.x,
+			::sphere[i][Y] * ::sphereSize - vertex.y,
+			::sphere[i][Z] * ::sphereSize - vertex.z
+		};
+		this->vbos[Surfaces].data << spherePoint.x << spherePoint.y << spherePoint.z;
+		// The points of the sphere are position vectors, which in this case are also unit normals.
+		this->vbos[Normals].data << ::sphere[i][X] << ::sphere[i][Y] << ::sphere[i][Z];
+		this->vbos[Colors].data
+			<< ::sphereColor.redF()
+			<< ::sphereColor.greenF()
+			<< ::sphereColor.blueF()
+			<< ::sphereColor.alphaF();
+	}
+}
+
+/*
+ * Uploads VBO data to the graphics card.
+ */
+void VertexCompiler::upload()
+{
+	for (const auto& vbo : this->vbos)
+	{
+		glBindBuffer(GL_ARRAY_BUFFER, vbo.buffer);
+		glBufferData(
+			GL_ARRAY_BUFFER,
+			countof(vbo.data) * sizeof(GLfloat),
+			vbo.data.constData(),
+			GL_STATIC_DRAW
+		);
+	}
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+}