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local xVelocity, yVelocity xVelocity, yVelocity = physicsObject:getLinearVelocity() if xVelocity > 0 then print( "Object goes right" ) end if xVelocity < 0 then print( "Object goes left" ) end if yVelocity > 0 then print( "Object goes down" ) end if yVelocity < 0 then print( "Object goes up" ) end |
find() uses a pattern syntax. A dot represents “any character.” This will match the first character of any string you search. In order to search for a literal dot, you need to doo this:
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local dotIndex = string.find(myString, "%."); |
In Corona, it is possible to save scores to an external text file. This can be accomplished using the following lines of code :
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local filePath = system.pathForFile( "score.txt", system.DocumentsDirectory ) // Here we are giving the path of the file to be opened and used as score.txt in the documents directory of the application. local myfile = io.open( filePath, "w" ) // We are opening the score.txt in write(w) mode so that we can write to it. File handling is done by the io class. So we are using the open method of io to open the external file. myfile:write(scoreStr) // We are writing the scoreStr, which is the string which contains the score value to the opened file using the write method. io.close(myfile) // After our use for the opened file, we have to close the file using the close method of io. |
This code snippet will save the score value in the scoreStr variable to the the file score.txt.
The following lines of code will help you to renames a file or directory in a corona SDK project:
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local destDir = system.DocumentsDirectory -- where the file is stored local results, reason = os.rename( system.pathForFile( "fileName.txt", destDir ), system.pathForFile( "apple.txt", destDir ) ) if results then print( "file is renamed" ) else print( "file is not renamed", reason ) end |
– if there is no such file, you will get the following the message in the console.
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file not renamed fileName.txt: No such file or directory |
There are types of rendering modes in corona SDK physics engine. The rendering modes are very much useful for the developers. Here I’ll show you how to choose any of these 3 rendering modes.
Code:
physics.setDrawMode( "debug" ) -- It will show collision engine outlines only.
physics.setDrawMode( "hybrid" ) -- It overlays collision outlines on normal Corona objects.
physics.setDrawMode( "normal" ) -- It is the default Corona renderer, with no collision outlines.
(Note: You can change the mode at any time, if you want)
as simple as that… 
Jumps the animation to the specified frame number or frame label specified by the setLabels()function.
object:stopAtFrame( frame )
eg:
myAnim:stopAtFrame(4)
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myAnim:play() |
This function is the same as display.save(), but it returns a display object instead of saving to a file by default. You can optionally save the capture to the device’s photo library.
syntax :
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display.capture( displayObject [, saveToPhotoLibraryFlag ] ) |
Example :
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local myObject1 = display.newRect( 50, 50, 100, 150 ) -- Create a rectangle object local myObject2 = display.newCircle( 100, 300, 50 ) -- Create a circle object local g = display.newGroup() g:insert(myObject1) g:insert(myObject2) -- save the entire group as a new display object local combined = display.capture( g ) -- position the new display object combined.x, combined.y = 100, 100 -- remove it combined:removeSelf() combined = nil |
Sets the x,y components of the global gravity vector, in units of m/s2. The default is ( 0, 9.8 ) to simulate standard Earth gravity, pointing downwards on the y-axis.
syntax
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physics.setGravity(gx,gy) |
gx
Sets the global gravity vector in X direction, in units of m/s2.
gy
Sets the global gravity vector in Y direction, in units of m/s2.
The mechanism used for ‘theming’ widgets is now completely different, and much more flexible. Themes are now external lua modules that you include in your project folder, which will have tables for the corresponding widgets. The individual widget tables in your theme file will have the parameters, and references to any graphics assets that are needed.
When a widget is instantiated, it first checks to see if there is a corresponding table in your theme file, with corresponding parameters. For parameters that aren’t found in your theme file, the default values are used. You can override any theme parameters by setting your own parameters when you create a widget.
Please use the official themes as a reference for creating your own themes. Download links for the current “official” themes are below:
To set a theme, use the widget.setTheme()
Create object for audio recording.
recording = media.newRecording( [path] )
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local filePath = system.pathForFile( dataFileName, system.DocumentsDirectory ) r = media.newRecording( filePath) r:startRecording( ) |
