# HG changeset patch
# User Teemu Piippo <teemu@hecknology.net>
# Date 1488575284 -7200
# Node ID 3a88e7a60b637230727a7395b2ed0893ce4577c6
# Parent  8661b9237ed5b8233456f4c97b22c9266842f259
At long last, the grid is finally now rendered onto the viewport. Woop!

diff -r 8661b9237ed5 -r 3a88e7a60b63 src/basics.h
--- a/src/basics.h	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/basics.h	Fri Mar 03 23:08:04 2017 +0200
@@ -315,3 +315,15 @@
 {
 	return ring.size();
 }
+
+/*
+ * Extracts the sign of x.
+ */
+template<typename T>
+T sign(T x)
+{
+	if (isZero(x))
+		return {};
+	else
+		return x / qAbs(x);
+}
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/canvas.cpp
--- a/src/canvas.cpp	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/canvas.cpp	Fri Mar 03 23:08:04 2017 +0200
@@ -90,6 +90,59 @@
 	}
 }
 
+/*
+ * Assuming we're currently viewing from a fixed camera, draw a backdrop into it. Currently this means drawing the grid.
+ */
+void Canvas::drawFixedCameraBackdrop()
+{
+	// Find the top left corner of the grid
+	Vertex topLeft = currentCamera().idealize(currentCamera().convert2dTo3d({0, 0}));
+	Vertex bottomRight = currentCamera().idealize(currentCamera().convert2dTo3d({width(), height()}));
+	qreal gridSize = grid()->coordinateSnap();
+	qreal x0 = sign(topLeft.x()) * (fabs(topLeft.x()) - fmod(fabs(topLeft.x()), gridSize));
+	qreal y0 = sign(topLeft.y()) * (fabs(topLeft.y()) - fmod(fabs(topLeft.y()), gridSize));
+	glEnable(GL_LINE_STIPPLE);
+	glBegin(GL_LINES);
+
+	static const auto prepareGridLine = [](qreal value) -> bool
+	{
+		if (not isZero(value))
+		{
+			if (isZero(fmod(value, 10.0)))
+				glColor4f(0, 0, 0, 0.6);
+			else
+				glColor4f(0, 0, 0, 0.25);
+
+			return true;
+		}
+		else
+		{
+			return false;
+		}
+	};
+
+	for (qreal x = x0; x < bottomRight.x(); x += gridSize)
+	{
+		if (prepareGridLine(x))
+		{
+			glVertex(currentCamera().realize({x, -10000, 999}));
+			glVertex(currentCamera().realize({x, 10000, 999}));
+		}
+	}
+
+	for (qreal y = y0; y < bottomRight.y(); y += gridSize)
+	{
+		if (prepareGridLine(y))
+		{
+			glVertex(currentCamera().realize({-10000, y, 999}));
+			glVertex(currentCamera().realize({10000, y, 999}));
+		}
+	}
+
+	glEnd();
+	glDisable(GL_LINE_STIPPLE);
+}
+
 bool Canvas::freeCameraAllowed() const
 {
 	return m_currentEditMode->allowFreeCamera();
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/canvas.h
--- a/src/canvas.h	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/canvas.h	Fri Mar 03 23:08:04 2017 +0200
@@ -43,6 +43,7 @@
 protected:
 	void contextMenuEvent(QContextMenuEvent* event) override;
 	void dragEnterEvent(QDragEnterEvent* event) override;
+	void drawFixedCameraBackdrop() override;
 	void dropEvent(QDropEvent* event) override;
 	bool freeCameraAllowed() const override;
 	void keyReleaseEvent(QKeyEvent* event) override;
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/glShared.h
--- a/src/glShared.h	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/glShared.h	Fri Mar 03 23:08:04 2017 +0200
@@ -27,6 +27,11 @@
 	glMultMatrixf(matrix.constData());
 }
 
+inline void glVertex(const Vertex& vertex)
+{
+	glVertex3f(vertex.x(), vertex.y(), vertex.z());
+}
+
 class LDObject;
 
 struct LDPolygon
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/glcamera.cpp
--- a/src/glcamera.cpp	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/glcamera.cpp	Fri Mar 03 23:08:04 2017 +0200
@@ -255,7 +255,7 @@
 	return matrix;
 }
 
-static const GLRotationMatrix ldrawToIdealAdapterMatrix = {1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1};
+static const GLRotationMatrix ldrawToIdealAdapterMatrix = {1, 0, 0, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, 0, 1};
 
 /*
  * Converts from rea co-ordinates to ideal co-ordinates.
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/glrenderer.cpp
--- a/src/glrenderer.cpp	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/glrenderer.cpp	Fri Mar 03 23:08:04 2017 +0200
@@ -381,10 +381,11 @@
 
 		glLoadIdentity();
 		const QSizeF& virtualSize = currentCamera().virtualSize();
-		glOrtho(-virtualSize.width(), virtualSize.width(), -virtualSize.height(), virtualSize.height(), -100.0f, 100.0f);
+		glOrtho(-virtualSize.width(), virtualSize.width(), -virtualSize.height(), virtualSize.height(), -1000.0f, 1000.0f);
 		glTranslatef(panning (X), panning (Y), 0.0f);
 		glMultMatrixf(currentCamera().transformationMatrix());
 		glMultMatrixf(ldrawToGLAdapterMatrix);
+		drawFixedCameraBackdrop();
 	}
 	else
 	{
@@ -1028,3 +1029,9 @@
 {
 	return m_model;
 }
+
+/*
+ * This virtual function lets derivative classes render something to the fixed camera
+ * before the main brick is rendered.
+ */
+void GLRenderer::drawFixedCameraBackdrop() {}
diff -r 8661b9237ed5 -r 3a88e7a60b63 src/glrenderer.h
--- a/src/glrenderer.h	Fri Mar 03 00:35:43 2017 +0200
+++ b/src/glrenderer.h	Fri Mar 03 23:08:04 2017 +0200
@@ -87,6 +87,7 @@
 
 protected:
 	void initializeGL();
+	virtual void drawFixedCameraBackdrop();
 	void keyPressEvent(QKeyEvent* event);
 	void keyReleaseEvent(QKeyEvent* event);
 	void leaveEvent(QEvent* event);