Tax season and SpreadsheetLight deal

It’s currently tax season. Making financial and tax reports can be taxing (haha!). I know, because I’ve spent years writing software that creates Excel reports for sales, revenue, debt and other financial reports.

So from now till the end 15th of April 2012, I’m offering my spreadsheet software library at the unbelievably low cost of USD 199 150. SpreadsheetLight runs on .NET Framework and Open XML SDK, is written in C#, uses the MIT License, and is designed to be easy to integrate into existing software projects with a minimum of fuss.

UPDATE: The promotion will be until 16th April 2012, and I’m selling it at USD 150. Need a spreadsheet library software? Get it now before I raise the price.

The reason is because I want you to have an easier time writing your programs. My experience in churning out Excel reports tells me it can be frustrating at times…

So check out SpreadsheetLight. Or get your manager to take a look.

Announcing SpreadsheetLight version 1.1

After much researching and programming and suffering (and tea), I’m happy to announce that version 1.1 of SpreadsheetLight is up! SpreadsheetLight is a spreadsheet manipulation library based on Open XML.

I added some functionality for defined names and clearing out data from rows/columns/cells. You can also split worksheet panes now. Version 1 didn’t have split pane functionality because I couldn’t find a way to make it easy for the programmer. Well, I wrote a function that allows you to do it with a minimum of fuss.

But the main bulk of version 1.1 updates is the insert/delete rows/columns part. Say you want to insert 4 rows at the 3rd row. This means all the rows from the 3rd row (including the 3rd row) must be shifted downwards 4 rows. Every merged cell, cell formula, table and defined name must be accounted for.

Merged cells need to be enlarged or trimmed off as needed. Or just simply deleted if it’s entirely within the delete range.

Tables need to be updated so the cell references within are correctly adjusted. If it used to contain C3:F6, after inserting 4 rows, it has to be C7:F10.

Cell formulas and defined names are sort of related, with the former typically of a more complex form than the latter. Consider taking on something like this:

= A1 +LOG10 +”BCD32″ -SUM($H6:Sheet1!K$9) *LOG10($F$5) + BCD32 – SUM(F2:G3)

That has to become this:

= A1 +LOG14 +”BCD32″ -SUM($H10:Sheet1!K$13) *LOG10($F$9) + BCD36 – SUM(F2:G7)

Note the LOG10 part. The first instance is a cell reference. The second is the logarithm function, base 10, of the cell originally $F$5. Note also that the first instance of BCD32 is a literal string. Literal strings should not be changed, even if they contain a valid cell reference.

That part took me quite a while. Let’s just say I’m glad I’m fairly proficient in regular expressions…

The only thing I left out was pictures (aka worksheet drawings) for insert/delete rows/columns. To create similar behaviour to when you’re doing it in Excel requires more arcane coding…

So if you’re looking for a spreadsheet library that’s light-weight yet capable of heavy-weight functionality, with simple-to-use functions, then consider SpreadsheetLight. Or tell your boss.

I’ve also included a Platinum version, which includes the source code of SpreadsheetLight (licensed with the MIT license). So if you want to know how I accomplished all that magic, consider the Platinum version then. Lots of comments to make the hairy parts less hairy…

Launching SpreadsheetLight

I am excited to tell you that my spreadsheet software library is available!

SpreadsheetLight

For the initial launch version (I decided to go for version 1. Why do people launch with versions 0.8? I don’t know…), you get comprehensive support for styles, rich text formatting, 47 named cell styles, themes (either one of the 20 built-in themes or create-your-own). Well, like I said, comprehensive styling support.

There’s also the (hum-drum) support for merging cells and freezing panes. I actually explored how to split panes. I certainly wrote about it in my Open XML guide, but it turns out that there’s a tiny rectangle at the top-left corner that Microsoft Excel didn’t tell me about. The size of that tiny rectangle is dependent on the font you use, and even the screen resolution of your computer screen.

While I could add a function that allows you to just input the size in EMUs (English Metric Units), I decided that if I can’t do it well, I don’t want to do it. At least for the initial launch.

Row heights and column widths were also big time drains. It turns out that they’re also dependent on the font and screen resolution of your computer screen. I was trying to calculate the standard row heights and column widths for the fonts in the built-in themes, and I thought I had them. I wrote a program using SpreadsheetLight to generate spreadsheets with different minor fonts, and I wrote a program to read in those spreadsheets and get the “standard” row height and column width. I spent 3 hours collecting data.

Then on a whim, I switched my computer screen’s resolution from 120 DPI to 96 DPI (my eyesight’s not that good ok? I need bigger text…), and whoa! All that data doesn’t apply anymore… All in all, I think I spent 6 or 7 days trying to figure out a general calculation formula. I failed. I don’t know how Excel does it.

I also surprised myself by including extensive support for pictures. I thought you just insert a picture into the worksheet and that’s it! It turns out there’s a ton of post-insertion manipulations you can do. For example, if your picture has transparent areas, you could set a background fill, and that background colour will be visible through the picture. Also, you can rotate the picture in 3D.

SpreadsheetLight is licensed under the MIT license. I decided to use one of the available software licenses instead of making up one of my own. As far as I can tell, the MIT license allows the recipient of the software to use the software in personal or commercial products. It’s also categorised as free software, as in freedom of use, not free as in cost. I don’t want to deal with per-client, or per-server, or per-developer or per-what-not licensing restrictions.

Even if you’re not interested in spreadsheet software, have a look at SpreadsheetLight. Tell some other programmer about it. Tell your manager about it. It took me slightly over 2 months of intense coding, and I want someone in the world out there to have an easier life because of SpreadsheetLight. Thanks!

Oh, and the image art is designed by Charlie Pabst from Charfish Design. While I have a fair competence in image work, I decided to get a professional designer to help me. It’s a business and professional product. I’m not going to risk the product’s success so I could stoke my ego…

Named cell styles are still explicitly declared

Styling cells in Microsoft Excel has its difficulties (as I’ve written before). The biggest one is keeping track of all the indices. In Open XML SDK, you have the ability to have a named cell style.

At first glance, you might think that’s awesome. You just use a named cell style, and all the related styles are applied. It’s like there’s a red car that uses hybrid fuels. “Yes, I would like to have a red car that uses hybrid fuels.” Not quite.

You see, the named cell style is dependent on the implementing spreadsheet software. For example, Microsoft Excel has the “Normal”, “Bad”, “Good” and “Neutral” named cell styles. But Google Spreadsheets and OpenOffice.org Calc do not have to have those named cell styles, or even style it the same as Microsoft Excel. This is where Open XML SDK isn’t quite “open”… After much research and work, I discovered the SDK is basically Open-XML-ising Microsoft Excel (and Word and PowerPoint). I’m neutral on the stands of open source and “forcing standards”. I just use whatever there is, and make something within the limitations.

Because of the dependency, the underlying individual styles need to be declared explicitly. Actually more so because of the dependency.

So for my spreadsheet software library SpreadsheetLight, I used Excel as the guideline.

In researching Excel named cell styles, I had to look at the underlying XML files (because Open XML spreadsheets are made of XML files). While the Open XML SDK comes with a document explorer (the Productivity Tool), I needed to make notes and also that I felt the need to see the XML file itself, rather than using the explorer tool.

This gave me a problem because while XML files are supposed to be human-readable, it doesn’t make it easy to read. The “natural” XML file has no indents. Oh my Godiva chocolate, it’s so hard to read… Then I remembered I had an XML tool, XML Studio. I fired that up and a few clicks later, the XML file had nice indents and I could find out where the individual style tags were. XML Studio was amazing to use.

Disclaimer: I was given a free developer license of XML Studio by Liquid Technologies. But the software is really useful if you work with XML files a lot.

After doing my notes for a while, I discovered even that’s not enough. There were too many individual styles! I needed the indices for those styles, because only the index was referenced in the final style (CellFormat classes). I didn’t really feel up to annotating the indices… until I remembered my partially completed Open XML spreadsheet decompiler tool. When I created that tool, one of my aims was to put in comments on the index of the individual styles.

Note to Liquid Technologies: You might want to consider putting in XML comments on the index of an XML child tag with respect to its parent. But I don’t know if that’s useful to programming spheres other than Open XML…

Anyway, my hard work paid off, and SpreadsheetLight allows you to apply named cell styles. Here’s how the spreadsheet looks like:
Applying named cell styles

Note that some of the named cell styles use accent colours. The accent colours are part of the spreadsheet’s theme. So in offering named cell styles as a feature, I also had to allow you to create your own theme. And here’s the code using SpreadsheetLight:

System.Drawing.Color[] clrs = new System.Drawing.Color[12];
clrs[0] = System.Drawing.Color.White;
clrs[1] = System.Drawing.Color.Black;
clrs[2] = System.Drawing.Color.WhiteSmoke;
clrs[3] = System.Drawing.Color.DarkSlateGray;
clrs[4] = System.Drawing.Color.DarkRed;
clrs[5] = System.Drawing.Color.OrangeRed;
clrs[6] = System.Drawing.Color.DarkGoldenrod;
clrs[7] = System.Drawing.Color.DarkOliveGreen;
clrs[8] = System.Drawing.Color.Navy;
clrs[9] = System.Drawing.Color.Indigo;
clrs[10] = System.Drawing.Color.SkyBlue;
clrs[11] = System.Drawing.Color.MediumPurple;

SLDocument sl = new SLDocument("ColourWheel", "Castellar", "Harrington", clrs);

sl.SetRowHeight(6, 24);
sl.SetColumnWidth(1, 1);
sl.SetColumnWidth(2, 13);
sl.SetColumnWidth(3, 13);
sl.SetColumnWidth(4, 13);
sl.SetColumnWidth(5, 13);
sl.SetColumnWidth(6, 13);
sl.SetColumnWidth(7, 13);

sl.SetCellValue(2, 2, "Normal");
sl.ApplyNamedCellStyle(2, 2, SLNamedCellStyleValues.Normal);
sl.SetCellValue(2, 3, "Bad");
sl.ApplyNamedCellStyle(2, 3, SLNamedCellStyleValues.Bad);
sl.SetCellValue(2, 4, "Good");
sl.ApplyNamedCellStyle(2, 4, SLNamedCellStyleValues.Good);
sl.SetCellValue(2, 5, "Neutral");
sl.ApplyNamedCellStyle(2, 5, SLNamedCellStyleValues.Neutral);

sl.SetCellValue(3, 2, "Calculation");
sl.ApplyNamedCellStyle(3, 2, SLNamedCellStyleValues.Calculation);
sl.SetCellValue(3, 3, "Check Cell");
sl.ApplyNamedCellStyle(3, 3, SLNamedCellStyleValues.CheckCell);
sl.SetCellValue(3, 4, "Explanatory Text");
sl.ApplyNamedCellStyle(3, 4, SLNamedCellStyleValues.ExplanatoryText);
sl.SetCellValue(3, 5, "Input");
sl.ApplyNamedCellStyle(3, 5, SLNamedCellStyleValues.Input);

sl.SetCellValue(4, 2, "Linked Cell");
sl.ApplyNamedCellStyle(4, 2, SLNamedCellStyleValues.LinkedCell);
sl.SetCellValue(4, 3, "Note");
sl.ApplyNamedCellStyle(4, 3, SLNamedCellStyleValues.Note);
sl.SetCellValue(4, 4, "Output");
sl.ApplyNamedCellStyle(4, 4, SLNamedCellStyleValues.Output);
sl.SetCellValue(4, 5, "Warning Text");
sl.ApplyNamedCellStyle(4, 5, SLNamedCellStyleValues.WarningText);

sl.SetCellValue(6, 2, "Heading 1");
sl.ApplyNamedCellStyle(6, 2, SLNamedCellStyleValues.Heading1);
sl.SetCellValue(6, 3, "Heading 2");
sl.ApplyNamedCellStyle(6, 3, SLNamedCellStyleValues.Heading2);
sl.SetCellValue(6, 4, "Heading 3");
sl.ApplyNamedCellStyle(6, 4, SLNamedCellStyleValues.Heading3);
sl.SetCellValue(6, 5, "Heading 4");
sl.ApplyNamedCellStyle(6, 5, SLNamedCellStyleValues.Heading4);
sl.SetCellValue(6, 6, "Title");
sl.ApplyNamedCellStyle(6, 6, SLNamedCellStyleValues.Title);
sl.SetCellValue(6, 7, "Total");
sl.ApplyNamedCellStyle(6, 7, SLNamedCellStyleValues.Total);

sl.SetCellValue(8, 2, "Accent1");
sl.ApplyNamedCellStyle(8, 2, SLNamedCellStyleValues.Accent1);
sl.SetCellValue(8, 3, "Accent2");
sl.ApplyNamedCellStyle(8, 3, SLNamedCellStyleValues.Accent2);
sl.SetCellValue(8, 4, "Accent3");
sl.ApplyNamedCellStyle(8, 4, SLNamedCellStyleValues.Accent3);
sl.SetCellValue(8, 5, "Accent4");
sl.ApplyNamedCellStyle(8, 5, SLNamedCellStyleValues.Accent4);
sl.SetCellValue(8, 6, "Accent5");
sl.ApplyNamedCellStyle(8, 6, SLNamedCellStyleValues.Accent5);
sl.SetCellValue(8, 7, "Accent6");
sl.ApplyNamedCellStyle(8, 7, SLNamedCellStyleValues.Accent6);

sl.SetCellValue(9, 2, "Accent1Perc60");
sl.ApplyNamedCellStyle(9, 2, SLNamedCellStyleValues.Accent1Percentage60);
sl.SetCellValue(9, 3, "Accent2Perc60");
sl.ApplyNamedCellStyle(9, 3, SLNamedCellStyleValues.Accent2Percentage60);
sl.SetCellValue(9, 4, "Accent3Perc60");
sl.ApplyNamedCellStyle(9, 4, SLNamedCellStyleValues.Accent3Percentage60);
sl.SetCellValue(9, 5, "Accent4Perc60");
sl.ApplyNamedCellStyle(9, 5, SLNamedCellStyleValues.Accent4Percentage60);
sl.SetCellValue(9, 6, "Accent5Perc60");
sl.ApplyNamedCellStyle(9, 6, SLNamedCellStyleValues.Accent5Percentage60);
sl.SetCellValue(9, 7, "Accent6Perc60");
sl.ApplyNamedCellStyle(9, 7, SLNamedCellStyleValues.Accent6Percentage60);

sl.SetCellValue(10, 2, "Accent1Perc40");
sl.ApplyNamedCellStyle(10, 2, SLNamedCellStyleValues.Accent1Percentage40);
sl.SetCellValue(10, 3, "Accent2Perc40");
sl.ApplyNamedCellStyle(10, 3, SLNamedCellStyleValues.Accent2Percentage40);
sl.SetCellValue(10, 4, "Accent3Perc40");
sl.ApplyNamedCellStyle(10, 4, SLNamedCellStyleValues.Accent3Percentage40);
sl.SetCellValue(10, 5, "Accent4Perc40");
sl.ApplyNamedCellStyle(10, 5, SLNamedCellStyleValues.Accent4Percentage40);
sl.SetCellValue(10, 6, "Accent5Perc40");
sl.ApplyNamedCellStyle(10, 6, SLNamedCellStyleValues.Accent5Percentage40);
sl.SetCellValue(10, 7, "Accent6Perc40");
sl.ApplyNamedCellStyle(10, 7, SLNamedCellStyleValues.Accent6Percentage40);

sl.SetCellValue(11, 2, "Accent1Perc20");
sl.ApplyNamedCellStyle(11, 2, SLNamedCellStyleValues.Accent1Percentage20);
sl.SetCellValue(11, 3, "Accent2Perc20");
sl.ApplyNamedCellStyle(11, 3, SLNamedCellStyleValues.Accent2Percentage20);
sl.SetCellValue(11, 4, "Accent3Perc20");
sl.ApplyNamedCellStyle(11, 4, SLNamedCellStyleValues.Accent3Percentage20);
sl.SetCellValue(11, 5, "Accent4Perc20");
sl.ApplyNamedCellStyle(11, 5, SLNamedCellStyleValues.Accent4Percentage20);
sl.SetCellValue(11, 6, "Accent5Perc20");
sl.ApplyNamedCellStyle(11, 6, SLNamedCellStyleValues.Accent5Percentage20);
sl.SetCellValue(11, 7, "Accent6Perc20");
sl.ApplyNamedCellStyle(11, 7, SLNamedCellStyleValues.Accent6Percentage20);

sl.SetCellValue(13, 2, 12345678);
sl.ApplyNamedCellStyle(13, 2, SLNamedCellStyleValues.Comma);
sl.SetCellValue(13, 4, 12345678);
sl.ApplyNamedCellStyle(13, 4, SLNamedCellStyleValues.Comma0);
sl.SetCellValue(14, 2, 12345678);
sl.ApplyNamedCellStyle(14, 2, SLNamedCellStyleValues.Currency);
sl.SetCellValue(14, 4, 12345678);
sl.ApplyNamedCellStyle(14, 4, SLNamedCellStyleValues.Currency0);
sl.SetCellValue(15, 2, 123);
sl.ApplyNamedCellStyle(156, 2, SLNamedCellStyleValues.Percentage);

sl.SaveAs("NamedCellStyles.xlsx");

I set the column widths of the 2nd to 7th column, and the row height of the 6th row so it’s easier to see.

The main body text (the minor font) is in Harrington, and the title font (major font) is Castellar. You will note that even though the major font is supposedly used for heading and title texts, only the named cell style Title uses the major font. The headings 1 through 4 use the minor font.

Pictures in Excel have way too much power…

You’d think inserting a picture into an Excel worksheet is pretty straightforward. If you’re just inserting the picture, then it is.

Then you check what other properties you can play with manipulating the picture. Woah amigo! There’s a whole plethora of options!

Excel picture format options

That’s like giving the typical user a (good enough) subset of rendering functions, including 3D. And here I thought you could just resize the picture, and maybe rotate it… If you’re not going for full 3D manipulation as in OpenGL or DirectX, Excel will do it for you.

Excel respects alpha/transparency of the picture (right now, I only know of PNG images that contain alpha information AND is fairly prevalent). And you can outline the picture and fill the transparent portions with a colour.

SpreadsheetLight picture fill and outline

You can even do shadows!

SpreadsheetLight picture shadows

Do you know it can take a phenomenal amount of work to get shadows working in 3D renderings? You’ve got to know the light source position, calculate the rays of light blocked by an object to create the illusion of a shadow (by creating a polygon that’s the outline of that object as described by those blocked rays of light). Well, technically speaking, Excel has got it easy, since the object is always a rectangle (an image).

Speaking of light, we can also do reflections. Let’s run a full gamut of the 3D power.

SpreadsheetLight 3D pictures

I lost the software keys to my 2 3D rendering software (Bryce 4 and TrueSpace). It sucked that I couldn’t render landscapes anymore… But, I’m seeing Excel as an alternative to getting some 3D-ish images.

Well, the above screenshots were from a spreadsheet generated by my software library, SpreadsheetLight. The library is based on the Open XML SDK, which in turn is based on what Excel can do. Here’s how the source code looks like:

SLDocument sl = new SLDocument(SLThemeTypeValues.Oriel);

SLPicture pic;

sl.SetCellValue(2, 2, "Accent 1");
sl.ApplyNamedCellStyle(2, 2, SLNamedCellStyleValues.Accent1);
sl.SetCellValue(2, 3, "Accent 2");
sl.ApplyNamedCellStyle(2, 3, SLNamedCellStyleValues.Accent2);
sl.SetCellValue(2, 4, "Accent 3");
sl.ApplyNamedCellStyle(2, 4, SLNamedCellStyleValues.Accent3);
sl.SetCellValue(2, 5, "Accent 4");
sl.ApplyNamedCellStyle(2, 5, SLNamedCellStyleValues.Accent4);
sl.SetCellValue(2, 6, "Accent 5");
sl.ApplyNamedCellStyle(2, 6, SLNamedCellStyleValues.Accent5);
sl.SetCellValue(2, 7, "Accent 6");
sl.ApplyNamedCellStyle(2, 7, SLNamedCellStyleValues.Accent6);

pic = new SLPicture("mandelbrot.png");
// anchor at cell (4,2) with 0 horizontal and vertical offsets.
pic.SetRelativePositionInPixels(4, 2, 0, 0);
sl.InsertPicture(pic);

pic = new SLPicture("mandelbrot.png");
pic.SetRelativePositionInPixels(4, 6, 0, 0);
pic.SetSolidFill(DocumentFormat.OpenXml.Drawing.SchemeColorValues.Accent3, 20);
pic.SetSolidOutline(DocumentFormat.OpenXml.Drawing.SchemeColorValues.Accent4, 0);
pic.SetOutlineStyle(4, DocumentFormat.OpenXml.Drawing.CompoundLineValues.Double, DocumentFormat.OpenXml.Drawing.PresetLineDashValues.LargeDash, DocumentFormat.OpenXml.Drawing.LineCapValues.Round, SLPicture.SLPictureJoinType.Bevel);
sl.InsertPicture(pic);

sl.AddWorksheet("Sheet2");

sl.SetCellValue(2, 2, "Accent 1");
sl.ApplyNamedCellStyle(2, 2, SLNamedCellStyleValues.Accent1);
sl.SetCellValue(2, 3, "Accent 2");
sl.ApplyNamedCellStyle(2, 3, SLNamedCellStyleValues.Accent2);
sl.SetCellValue(2, 4, "Accent 3");
sl.ApplyNamedCellStyle(2, 4, SLNamedCellStyleValues.Accent3);
sl.SetCellValue(2, 5, "Accent 4");
sl.ApplyNamedCellStyle(2, 5, SLNamedCellStyleValues.Accent4);
sl.SetCellValue(2, 6, "Accent 5");
sl.ApplyNamedCellStyle(2, 6, SLNamedCellStyleValues.Accent5);
sl.SetCellValue(2, 7, "Accent 6");
sl.ApplyNamedCellStyle(2, 7, SLNamedCellStyleValues.Accent6);

pic = new SLPicture("mandelbrot.png");
pic.SetRelativePositionInPixels(4, 2, 0, 0);
// transparency 0%, blur 6pt, angle 90 degrees, distance 3pt
pic.SetInnerShadow(DocumentFormat.OpenXml.Drawing.SchemeColorValues.Accent1, 0, 6, 90, 3);
sl.InsertPicture(pic);

pic = new SLPicture("mandelbrot.png");
pic.SetRelativePositionInPixels(4, 6, 0, 0);
// transparency 50%, horizontal size 100%, vertical size -23%, horizontal skew -13.34%, vertical skew 0%
// blur 6pt, angle 45 degrees, distance 3pt
// origin at picture's bottom left, don't rotate with picture.
pic.SetPerspectiveShadow(DocumentFormat.OpenXml.Drawing.SchemeColorValues.Accent2, 50, 100, -23, -13.34m, 0, 6, 45, 3, DocumentFormat.OpenXml.Drawing.RectangleAlignmentValues.BottomLeft, false);
sl.InsertPicture(pic);

sl.AddWorksheet("Sheet3");

sl.SetCellValue(2, 2, "Accent 1");
sl.ApplyNamedCellStyle(2, 2, SLNamedCellStyleValues.Accent1);
sl.SetCellValue(2, 3, "Accent 2");
sl.ApplyNamedCellStyle(2, 3, SLNamedCellStyleValues.Accent2);
sl.SetCellValue(2, 4, "Accent 3");
sl.ApplyNamedCellStyle(2, 4, SLNamedCellStyleValues.Accent3);
sl.SetCellValue(2, 5, "Accent 4");
sl.ApplyNamedCellStyle(2, 5, SLNamedCellStyleValues.Accent4);
sl.SetCellValue(2, 6, "Accent 5");
sl.ApplyNamedCellStyle(2, 6, SLNamedCellStyleValues.Accent5);
sl.SetCellValue(2, 7, "Accent 6");
sl.ApplyNamedCellStyle(2, 7, SLNamedCellStyleValues.Accent6);

pic = new SLPicture("mandelbrot.png");
pic.SetRelativePositionInPixels(6, 3, 0, 0);
pic.SetFullReflection();
// width 6pt, height 6pt
pic.Set3DBevelBottom(DocumentFormat.OpenXml.Drawing.BevelPresetValues.Convex, 6, 6);
// width 3pt, height 4pt
pic.Set3DBevelTop(DocumentFormat.OpenXml.Drawing.BevelPresetValues.ArtDeco, 3, 4);
// extrusion colour transparency 0%, extrusion (or depth) height 15 pt
pic.Set3DExtrusion(System.Drawing.Color.Green, 0, 15);
// contour colour transparency 40%, contour width 4pt
pic.Set3DContour(DocumentFormat.OpenXml.Drawing.SchemeColorValues.Accent3, 40, 4);
pic.Set3DMaterialType(DocumentFormat.OpenXml.Drawing.PresetMaterialTypeValues.TranslucentPowder);
// 5 pt above "ground"
pic.Set3DZDistance(5);
// field of view 105 degrees, zoom 100%
// camera latitude, longitude, revolution in degrees (50, 40, 30)
// light rig latitude, longitude, revolution in degrees (0, 0, 30)
pic.Set3DScene(DocumentFormat.OpenXml.Drawing.PresetCameraValues.PerspectiveFront, 105, 100, 50, 40, 30, DocumentFormat.OpenXml.Drawing.LightRigValues.Sunrise, DocumentFormat.OpenXml.Drawing.LightRigDirectionValues.TopLeft, 0, 0, 30);
sl.InsertPicture(pic);

sl.SaveAs("Pictures.xlsx");

I use the enumerations available in Open XML SDK as far as possible. This means you can sort of port over any programs you have written using Open XML SDK. And also that I don’t have to invent my own enumerations that are essentially copies of the SDK enumerations.

One thing that confused me was the 3D rotation options in Excel.

SpreadsheetLight 3D picture rotation options

Excel used the vertical “axis” as the X value, and the horizontal “axis” as the Y value. To the user, the X, Y and Z values are like the first, second and third values of … something.

To me, X, Y and Z have special meanings, particularly when applied to the context of 3D. Those values don’t even increase in a consistent manner. The X value decreases if you use the right-hand rule (the left button), but the Y and Z values increase when you use the right-hand rule (left and right buttons respectively).

The Open XML SDK then complicates matters by using the terms latitude, longitude and revolution. Each ranging from 0 degrees to 359.9 degrees (or strictly less than 360 degrees in other words).

And in case you’re wondering about the state of the spreadsheet library progress, I froze the feature set of SpreadsheetLight for version 1. Otherwise, I’d never get it shipped. I’m now documenting the hashbrown out of the source code. The point is to make it ridiculously easy for a programmer to pick up SpreadsheetLight and start using it (without having to refer to a manual, which I’ll also be writing).