Setting Pixels
Dear Revolutionaries I hope you are all having a happy holiday. Mine started really well as the copy of Dan Shafer's book I had ordered, arrived the day I was leaving for the holidays :-) I have thoroughly enjoyed reading it these last few days and recommend it whole-heartedly to any fellow rev newbies (it's available on the runrev website) - so when do the next two volumes come out? Here is my question - Dan's book describes the use of the 'mouseColor' handler to get the color value of the pixel that is below the mouse - is there any way in rev, to set the value of an individual pixel? Best Gordon = :: Gordon Webster :: ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels
Recently, Gordon Webster wrote: Here is my question - Dan's book describes the use of the 'mouseColor' handler to get the color value of the pixel that is below the mouse - is there any way in rev, to set the value of an individual pixel? See Ken Ray's useful explanation here: http://sonsothunder.com/devres/metacard/tips/imag003.htm This explains how imageData, alphaData and maskData work. It may be a bit overwhelming at first, but there's some sample code included to get you started. (I just used this last night -- thank Ken!) Regards, Scott Rossi Creative Director Tactile Media, Development Design - E: [EMAIL PROTECTED] W: http://www.tactilemedia.com ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels - Clarification
Ken wrote: This is something that as you identified is too slow to be done in regular Transcript. You need the help of an external to do the processing of the imageData for you. You might want to check out Chipp Walters' image tools at: http://www.altuit.com/webs/altuit2/RunRev/Downloads.htm There's image compositing and convolution matrix utilities there that use an external for speed. There is an external for Windows (ddl). How can I get en external for MAC to speed up the process? Best regards, Paolo Mazza ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels - Any geeks out there?
For those of you who are interested in graphics, I DO suggest you try Monte's custom paint tool for simply drawing squiggly lines with the mouse. In terms of coding, and since Monte has proved to us all that he is quite good at this kind of thing, I think that this routine is probably about as efficient as it can be. Yet on my Pentium II (Windows ME), the result is not very good, certainly not as good as it would be in VB. The mouse draws a broken rather than continuous line, even when you move it slowly. So contradict me if I am wrong: The development of a procedure for direct access to the image's pixel data (rather than having instructions like 'put the imageData of image bmw.bmp into iData, set the imageData of image bmw.bmp to iData', etc.) would probably help a lot. But as I said, it would take a real bright spark (someone with internal knowledge of the Transcript engine) to come up with such a solution. However, they did it in VB... ARE THERE ANY GEEKS OUT THERE? When the RunRev team get their heads above water, I would also like to know what they think about this issue. Here's Monte's routine again: -Button script on mouseUp InitialiseImageData InitialisePaintColor end mouseUp -Card script local lImageData,lPaintColor,lMouseDown on InitialiseImageData put the imageData of image 1 into lImageData end InitialiseImageData on InitialisePaintColor put binaryEncode(,0,0,255,0) into lPaintColor end InitialisePaintColor on mouseMove x,y if lMouseDown then if word 1 of the target is image then set the lockCursor to true set the cursor to cross put (x-the left of image 1)*4+(y- the top of image 1)*(the width of image 1*4) into x put lPaintColor into char x-3 to x of lImageData set the imageData of image 1 to lImageData end if else pass mouseMove end if end mouseMove on mouseDown put true into lMouseDown end mouseDown on mouseUp put false into lMouseDown end mouseUp on mouseRelease put false into lMouseDown end mouseRelease ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels - Congratulations Monte!
Monte has beat us ALL to the punch! Making his recommended alterations to the little test routine shows us that there is no substitute for a good knowledge of the timing aspects of the Transcript language. The timings on my machine are similar to his. Thanks Monte! So now I can apply all that has been recommended and try a real eraser test. Who knows, it might be agile enough to implement in pure Transcript. That said, of course the problem becomes analogous to the one I had in VB. Pure VB worked more or less OK, but some bright spark eventually found a way of accessing the image data directly, so that procedures like - put the imageData of image bmw.bmp into iData set the imageData of image bmw.bmp to iData - became unnecessary. Consequently, the advice DON'T use VB for graphics became far less true, although of course it is a long way from being an instrument for constructing games. To achieve something similar in Transcript might also be an advantage in terms of speed leading to the statement You CAN use Transcript for graphics (but not for games?), but it would take someone who has a really deep knowledge of the internal workings of the system to come up with such an image bitmap pointer procedure (someone from the RunRev team or a geek working at the university?). Anyway, I am very happy for now. Many thanks to all who have contributed to the solution of setting pixels. I feel inspired enough by your obvious interest to actually go off and learn more about what I now consider to be a viable new language. ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels - Congratulations Monte!
GREAT JOB folks! djl At 02:04 PM 1/30/03 -0200, you wrote: Monte has beat us ALL to the punch! Making his recommended alterations to the little test routine shows us that there is no substitute for a good knowledge of the timing aspects of the Transcript language. The timings on my machine are similar to his. Thanks Monte! So now I can apply all that has been recommended and try a real eraser test. Who knows, it might be agile enough to implement in pure Transcript. That said, of course the problem becomes analogous to the one I had in VB. Pure VB worked more or less OK, but some bright spark eventually found a way of accessing the image data directly, so that procedures like - put the imageData of image bmw.bmp into iData set the imageData of image bmw.bmp to iData - became unnecessary. Consequently, the advice DON'T use VB for graphics became far less true, although of course it is a long way from being an instrument for constructing games. To achieve something similar in Transcript might also be an advantage in terms of speed leading to the statement You CAN use Transcript for graphics (but not for games?), but it would take someone who has a really deep knowledge of the internal workings of the system to come up with such an image bitmap pointer procedure (someone from the RunRev team or a geek working at the university?). Anyway, I am very happy for now. Many thanks to all who have contributed to the solution of setting pixels. I feel inspired enough by your obvious interest to actually go off and learn more about what I now consider to be a viable new language. ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution == || Dave LeYanna || || Director IS || || Right to Life of Michigan|| == ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
RE: Setting Pixels - More answers to suggestions
Hi All I never read the original problem but I just made a custom paint tool with this: -- button script on mouseUp InitialiseImageData InitialisePaintColor end mouseUp -- card script local lImageData,lPaintColor,lMouseDown on InitialiseImageData put the imageData of image 1 into lImageData end InitialiseImageData on InitialisePaintColor put binaryEncode(,0,0,255,0) into lPaintColor end InitialisePaintColor on mouseMove x,y if lMouseDown then if word 1 of the target is image then set the lockCursor to true set the cursor to cross put (x-the left of image 1)*4+(y- the top of image 1)*(the width of image 1*4) into x put lPaintColor into char x-3 to x of lImageData set the imageData of image 1 to lImageData end if else pass mouseMove end if end mouseMove on mouseDown put true into lMouseDown end mouseDown on mouseUp put false into lMouseDown end mouseUp on mouseRelease put false into lMouseDown end mouseRelease Hope you like drawing squigly lines ;-) Monte ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels - More answers to suggestions
Hi Robert, Yes, an XCMD is like a DLL only for Macs. It means external command (there are also XFCNs - external functions). I have a script that converts RGB - HSV if you are interested. As Monte and others have shown, scripting in different ways can dramatically alter the speed of execution. Perhaps my script might be as fast as your DLL :-) If you would like me to send it, email me off-list. Cheers, Sarah On Thursday, January 30, 2003, at 02:17 pm, Robert J Warren ((Howsoft.com)) wrote: Thanks, and sorry Chipp, I am not only new to Transcript but I also know nothing at all about Macs. I presume that an XCMD is the Mac version of a Windows DLL (?) I am sure that it would help, but I am not sure to what degree. I have only ever written one DLL in my life which is for the said eraser program in VB (due to be launched soon). It converts RGB to HSL and v.v. By doing the calculations in a DLL rather than in the program the saving was about 15%. Although this 15% was crucial in the eraser routine I wrote, it was generally a disappointment: I expected a much bigger saving. ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
RE: Setting Pixels (for Jim Hurley)
Jim, tried to send this offlist, but was blocked by: dnsbl.njabl.org Hey Jim! Nice stack! Though I'm having a bit of a problem working with it I opened it in RR1.5 on a PC and it doesn't want to work. I see you have many variables called 'num' in the stack script. 'num' is a reserverd transcript term, so it won't work (at least not on my PC:-) I'd like to play with your stack. Let me know if you get around to fixing it! Thanks for supporting RR. best, Chipp Robert, Just to add a bit to Scott's good advice: If you would like some tools to facilitate this kind of drawing, the ideal is Turtle Graphics. Jim Hurley ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
RE: Setting Pixels
Hi Bob, From the examples, this seems to mean in practice that if I want to change a single pixel in an image I need to read the whole image bitmap into a variable, change the pixel in the variable, and then copy the whole variable contents back into the image. Much easier to edit the image via script with a pencil. on mouseUp select img 1 choose pencil drag from topLeft of img 1 to botRight of img 1 choose browse end mouseUp This could easily be set up to modify a single pixel in an image.. for instance a button with: on mouseUp changeThisPixel 3,7,test,red end mouseUp on changeThisPixel pDeltaX,pDeltaY,pImg,pColor select img pImg choose pencil set the penColor to pColor put left of img pImg + pDeltaX into tXpixel put top of img pImg + pDeltaY into tYpixel click at tXpixel,tYpixel choose browse end changeThisPixel it's instant on my machine -Chipp ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels
Hi Jim, .. The good people at RR have posted a demo stack in the Education page on the RunRev site: http://www.runrev.com/revolution/education/usercontributions.html Check the User Contributions. This is intended primarily for an elementary course in programing in Transcript and Turtle Graphics for science students, but it may also work for you. Jim Hurley i also would like to take a look at turtles. Heard it very often in the past, but still have no idea what i means. Unfortunately i cannot get it work. A look at your scripts showed me the reason. You use lots of reserved word in your handlers, be it as a handler name (left, right, home etc...) or names of variables (num as the most obvious example). I would really appreciate if you could take a look again and change your stack. Thanks a lot in advance. Regards Klaus Major [EMAIL PROTECTED] ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels - Answers to Suggestions
First of all, I would like to thank the various members of the list who have given me a number of interesting suggestions in relation to my pixels problem. All info has been gratefully received. Thanks also to those who have given me advice in relation to the originally stated (but oversimplified) drawing problem. I'm learning a lot! In response to - How long does it take to copy an image? Maybe you can cut that in half by doing the read the whole image bitmap only once. - the whole problem is that in the eraser routine the image needs to be continuously and permanently updated and also displayed on the screen according to every tiny movement of the eraser. The idea of copying the whole image into a variable or array, extracting and processing a portion of it and then replacing the whole image may be OK if it is done once, but not repeatedly as required by the eraser routine. In Transcript, the original copying of the image data to a variable is in fact quite quick, but the processing, replacement and copying back of the image is far too slow. According to the method outlined by Ken Ray in his article, I tried a test replacement of a mere 400 pixels, and this took various seconds! Part of the trouble is that Transcript does not appear to have instructions for simply reading or replacing individual pixels, which might alleviate the problem to some degree. However, ironically, as I have found out in VB, this is not the best solution. For maximum speed you have to process the image's pixel data directly. Putting even part of the pixel data into a variable or array for processing slows the whole thing down too much, and don't forget that quite complex mathematical calculations have to be performed on each pixel, which if done correctly can also take up considerable time. I have solved this problem in VB, but only by using non-standard pointer routines to find and process the image data. VB also has instructions (e.g. PaintPicture) for overlaying parts of the image data. VB is pretty fast with regard to mathematical processing. Nevertheless, in spite of my success, the general advice to VB programmers is to use DirectX (or C++) rather than normal VB, which because of its complexity I am not too inclined to do at the moment! From what I have seen so far, Transcript is more limited in all of these respects. In short, it appears not to have been made for this kind of graphical processing. However, if any improvements could be made in #2 (or #3???), e.g. the inclusion of instructions for setting individual pixels, some equivalent of PaintPicture, etc., I would be eternally grateful. Ken Ray himself has hit the nail on the head: This is something that as you identified is too slow to be done in regular Transcript. You need the help of an external to do the processing of the imageData for you. You might want to check out Chipp Walters' image tools at: http://www.altuit.com/webs/altuit2/RunRev/Downloads.htm There's image compositing and convolution matrix utilities there that use an external for speed. I hope it works for you, Me too! Thanks Ray! Bob Warren ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
RE: Setting Pixels - Answers to Suggestions
Bob, I've thought some about this problem. If you can't use the direct editing mode (choose pencil, eraser, etc..), then it will probably be too slow. Perhaps a DLL or XCMD would do the trick... -Chipp ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels - Answers to Suggestions
On Wednesday, January 29, 2003, at 11:39 AM, Robert J Warren ((Howsoft.com)) wrote: According to the method outlined by Ken Ray in his article, I tried a test replacement of a mere 400 pixels, and this took various seconds! Part of the trouble is that Transcript does not appear to have instructions for simply reading or replacing individual pixels, which might alleviate the problem to some degree. However, ironically, as I have found out in VB, this is not the best solution. For maximum speed you have to process the image's pixel data directly. Putting even part of the pixel data into a variable or array for processing slows the whole thing down too much, and don't forget that quite complex mathematical calculations have to be performed on each pixel, which if done correctly can also take up considerable time. I need to read Ken Ray's article. I suspect his examples are designed for clarity rather than efficiency. Char chunking for getting data is fast. Char chunking for replacing data can be slow. Specifically, ... Assume operations are on a copy of the image. Char chunking for getting pixel data is fast. However, char chunking for replacing pixel data goes up with the size of the image. (It might be nice if replacement noticed the size was the same and did the replacement in place, but alas, that doesn't seem to be the case.) It is thus better to replace the entire pixel rather than each individual pixel component in an image of nontrivial size. And, as mentioned in #3 below, it is better to replace sub-rows than pixels. Here are a couple things to try. 1 There may be places in which it is better to refer to the image data (or sub-image) by reference and refer to parts of it by that and char positions. 2 There may be ways you can avoid repeating row-column calculations. Use a function to create a char pointer from row and column and use that as you need. For example, you don't need to calculate the position for both the read and the write. 3 After you are happy with your method, change the atomic operation from pixel orientation to sub-row orientation. This handler should work on a sequence of pixels (as specified by char positions) and need not know anything about the size of the image. That is, you don't have to do a row-column calculation for each pixel and replacement is directly by char pointer. If you need a few pixel oriented operators but don't use them often, build them out of the sub-row operators. Remember, build up your new sub-row, then replace it in one operation. If you prefer a functional style, you can use a string function to operate on a an sequence of pixels and return a string of pixels and then put things together at the higher level. With that optimization, the char chunking replacement will be less of a hit; you will be doing only one replacement per row under your wand. It the image can be lots taller than the wand, you may want to select out the applicable rows, make the transformation, then then put it all back together. Dar Scott ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels - More answers to suggestions
I've thought some about this problem. If you can't use the direct editing mode (choose pencil, eraser, etc..), then it will probably be too slow. Perhaps a DLL or XCMD would do the trick... -Chipp Thanks, and sorry Chipp, I am not only new to Transcript but I also know nothing at all about Macs. I presume that an XCMD is the Mac version of a Windows DLL (?) I am sure that it would help, but I am not sure to what degree. I have only ever written one DLL in my life which is for the said eraser program in VB (due to be launched soon). It converts RGB to HSL and v.v. By doing the calculations in a DLL rather than in the program the saving was about 15%. Although this 15% was crucial in the eraser routine I wrote, it was generally a disappointment: I expected a much bigger saving. But perhaps more important is the fact that I would have a program which was not truly cross-platform. Apart from the simple elegance of the Transcript language, the cross-platform aspect is my main attraction. Rather than regard it as a fixed entity, I would frankly prefer to see the Transcript language corrected, improved and adequately extended. But I don't suppose the RunRev team would be listening at the moment as it seems they are occupied by some other minor task. From Dar Scott: I need to read Ken Ray's article. I suspect his examples are designed for clarity rather than efficiency. Char chunking for getting data is fast. Char chunking for replacing data can be slow. Specifically, ... Assume operations are on a copy of the image. Char chunking for getting pixel data is fast. However, char chunking for replacing pixel data goes up with the size of the image. (It might be nice if replacement noticed the size was the same and did the replacement in place, but alas, that doesn't seem to be the case.) It is thus better to replace the entire pixel rather than each individual pixel component in an image of nontrivial size. And, as mentioned in #3 below, it is better to replace sub-rows than pixels. Here are a couple things to try. 1 There may be places in which it is better to refer to the image data (or sub-image) by reference and refer to parts of it by that and char positions. 2 There may be ways you can avoid repeating row-column calculations. Use a function to create a char pointer from row and column and use that as you need. For example, you don't need to calculate the position for both the read and the write. 3 After you are happy with your method, change the atomic operation from pixel orientation to sub-row orientation. This handler should work on a sequence of pixels (as specified by char positions) and need not know anything about the size of the image. That is, you don't have to do a row-column calculation for each pixel and replacement is directly by char pointer. If you need a few pixel oriented operators but don't use them often, build them out of the sub-row operators. Remember, build up your new sub-row, then replace it in one operation. If you prefer a functional style, you can use a string function to operate on a an sequence of pixels and return a string of pixels and then put things together at the higher level. With that optimization, the char chunking replacement will be less of a hit; you will be doing only one replacement per row under your wand. It the image can be lots taller than the wand, you may want to select out the applicable rows, make the transformation, then then put it all back together. Thanks a lot Dar. There's a lot of useful stuff there. But I haven't got to the bitmap's rows and columns yet. I've just tried to replace the first 400 pixels (first row) of a 657 pixels wide photo, with no calculations on the pixels at all. The following little routine is designed simply to replace the first 400 pixels of a photo. Since I have almost no experience in Transcript, please excuse anything stupid I may have done. bmw.bmp is a Windows bitmap of 657x319 pixels. It occupies 614K on mouseUp put empty into iData put binaryEncode(,0,0,255,0) into redPixel put the imageData of image bmw.bmp into iData delete char 1 to 1600 of iData repeat with i = 1 to 400 put redPixel before iData end repeat set the imageData of image bmw.bmp to iData play beep end mouseUp On my (admittedly humble Pentium II 450hz 128M memory) PC, the above little routine takes almost 8 seconds to execute! So what stupid things have I done to make such a modest little routine take 8 whole seconds to execute? I am sure that improvements can be made in the coding to make it faster (e.g. the repeat bit), but 8 seconds is almost like a century in computer time! Any comments on the above routine? ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
RE: Setting Pixels - More answers to suggestions
I think you can speed this up just a litle bit on the first run by changing: if tData = then put char 1601 to -1 of the imageData of image 1 \ into tData end if This ought to be slightly faster as the engine doesn't have to resize the tData variable again, nor push its contents forwards upon deleting from the front. Yep Back down to 0.162 I think what I'd do would be to initialise the data when the image was first opened. Say openStack? Monte ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels
Recently, Robert J Warren (Howsoft.com) wrote: All I want to do is something which is as easy as falling off a log in VB. I want to move the mouse around a window (over an image perhaps, but not necessarily) and to draw a line of pixels as I go - i.e. construct a very primitive drawing program. I would be grateful if anyone could help. Sounds like you could simply use the paint tools and an image object overlaying whatever you want to draw on. See the docs under choosing tools (choose command) and: - pencil - brush - spray can - bucket Alternatively, you could use draw graphics, using the curve tool for free-form drawing, or primitive shapes and polygons, but this can create multiple objects, depending on how you implement it. Hopefully there's something here you can use. Regards, Scott Rossi Creative Director Tactile Media, Multimedia Design - E: [EMAIL PROTECTED] W: http://www.tactilemedia.com ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels
Recently, Robert J Warren (Howsoft.com) wrote: All I want to do is something which is as easy as falling off a log in VB. I want to move the mouse around a window (over an image perhaps, but not necessarily) and to draw a line of pixels as I go - i.e. construct a very primitive drawing program. I would be grateful if anyone could help. Sounds like you could simply use the paint tools and an image object overlaying whatever you want to draw on. See the docs under choosing tools (choose command) and: - pencil - brush - spray can - bucket Alternatively, you could use draw graphics, using the curve tool for free-form drawing, or primitive shapes and polygons, but this can create multiple objects, depending on how you implement it. Hopefully there's something here you can use. Regards, Scott Rossi Creative Director Tactile Media, Multimedia Design Robert, Just to add a bit to Scott's good advice: If you would like some tools to facilitate this kind of drawing, the ideal is Turtle Graphics. You can control the turtle (drawing cursor) with such simple commands as: Relative tools (independent of a coordinate system): Forward,Back, Left, Right, setHeading, etc. Absolute tools (coordinate based): setXY, incrementXY, xyCoordinates(), xCor() etc. . The good people at RR have posted a demo stack in the Education page on the RunRev site: http://www.runrev.com/revolution/education/usercontributions.html Check the User Contributions. This is intended primarily for an elementary course in programing in Transcript and Turtle Graphics for science students, but it may also work for you. Jim Hurley ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Setting Pixels
Dear Jim, Many thanks for the very interesting advice on the setting pixels problem. I'll certainly follow it up. Regards, Bob Warren ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Setting Pixels - Clarification
On Tuesday, January 28, 2003, at 07:24 PM, Robert J Warren ((Howsoft.com)) wrote: From the examples, this seems to mean in practice that if I want to change a single pixel in an image I need to read the whole image bitmap into a variable, change the pixel in the variable, and then copy the whole variable contents back into the image. Surely not! This is an incredibly slow process. How long does it take to copy an image? Maybe you can cut that in half by doing the read the whole image bitmap only once. Dar Scott ___ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
