The '''POINT''' function returns the pixel [[COLOR]] attribute at a specified graphics coordinate or the current graphic cursor position. ''Color'' {{PageSyntax}} ::::color_attribute% = '''POINT ('''''column%, row%''''')''' ''Graphic cursor position'' {{PageSyntax}} ::::pointer_coordinate% = '''POINT('''{0|1|2|3}''')''' {{Parameters}} Graphic Color syntax: * The [[INTEGER]] ''column'' and ''row'' coordinates designate the pixel position color on the screen to read. * The return value is an [[INTEGER]] palette attribute value or an [[_UNSIGNED]] [[LONG]] [[_RGBA]] 32 bit value in QB64. Graphic cursor position syntax: * The [[INTEGER]] position number can be 0 to 3 depending on the cursor position desired: ** POINT(0) returns the current graphic cursor [[SCREEN]] column pixel coordinate. ** POINT(1) returns the current graphic cursor [[SCREEN]] row pixel coordinate. ** POINT(2) returns the current graphic cursor [[WINDOW]] column position. ** POINT(3) returns the current graphic cursor [[WINDOW]] row position. * If a [[WINDOW]] view port has not been established, the coordinate returned will be the [[SCREEN]] cursor pixel position. * The return value is the current graphic cursor ''column'' or ''row'' pixel position on the [[SCREEN]] or [[WINDOW]]. * Graphic cursor positions returned will be the last ones used in a graphic shape such as a [[CIRCLE]] center point. ''Usage:'' * Use '''[[_SOURCE]]''' first to set the image handle that POINT should read or QB64 will assume the current source image. :: '''{{text|_SOURCE 0|green}}''' 'sets POINT to read the current SCREEN image after reading a previous source image * '''POINT cannot be used in SCREEN 0!''' Use the [[SCREEN (function)|SCREEN]] function to point text character codes and colors in SCREEN 0. <center>'''POINT in Qbasic Legacy Graphic SCREEN Modes:'''</center> * The [[INTEGER]] color attributes returned are limited by the number of colors in the legacy SCREEN mode used. * ''Column'' and ''row'' [[INTEGER]] parameters denote the graphic pixel coordinate to read. * In '''QB64''' the offscreen or off image value returned is -1. Use IF POINT(x, y) <> -1 THEN... * In Qbasic the coordinates MUST be on the screen or an [[ERROR Codes|Illegal Function Call error]] will occur. <center>'''POINT in QB64 32 Bit Graphic [[_NEWIMAGE]] or [[_LOADIMAGE]] Modes:'''</center> * Returns [[_UNSIGNED]] [[LONG]] 32 bit color values. Use [[_UNSIGNED]] values when you don't want negative values. * '''[[_UNSIGNED]] [[LONG]] variables should be used when comparing POINT returns with [[_RGB]] or [[_RGB32]] [[_ALPHA]] bit values''' * Convert 32 bit color values to RGB intensities(0 to 255) using the [[_RED32]], [[_GREEN32]] and [[_BLUE32]] functions. * To convert color intensities to OUT &H3C9 color port palette intensity values divide the values of 0 to 255 by 4. * Use the [[_PALETTECOLOR (function)]] to convert color port palette intensities in 32 bit modes. ''Example 1:'' How [[_RGB]] 32 bit values return [[DOUBLE]] or [[_UNSIGNED]] [[LONG]] values in QB64. {{CodeStart}} '' '' {{Cl|DIM}} clr {{Cl|AS}} {{Cl|LONG}} 'DO NOT use LONG in older versions of QB64 (V .936 down) {{Cl|SCREEN}} {{Cl|_NEWIMAGE}}(640, 480, 32) {{Cl|CLS}} , {{Cl|_RGB}}(255, 255, 255) 'makes the background opaque white {{Cl|PRINT}} "POINT(100, 100) ="; {{Cl|POINT}}(100, 100) clr = {{Cl|POINT}}(100, 100) {{Cl|PRINT}} "Variable clr = "; clr {{Cl|IF...THEN|IF}} clr = {{Cl|_RGB}}(255, 255, 255) {{Cl|THEN}} {{Cl|PRINT}} "Long OK" {{Cl|IF...THEN|IF}} {{Cl|POINT}}(100, 100) = {{Cl|_RGB}}(255, 255, 255) {{Cl|THEN}} {{Cl|PRINT}} "_RGB OK" {{Cl|IF...THEN|IF}} {{Cl|POINT}}(100, 100) = clr {{Cl|THEN}} {{Cl|PRINT}} "Type OK" 'will not print with a LONG variable type'' '' {{CodeEnd}} :'''Note:''' Change the DIM ''clr'' variable type to [[LONG]] to see how the last IF statement doesn't PRINT as shown in the output below: {{OutputStart}}POINT(100, 100) = 4294967295 Variable clr = -1 Long OK _RGB OK {{OutputEnd}} ''Example 2:'' Using a POINT mouse routine to get the 32 bit color values of the QB64 Bee. [http://www.qb64.net/forum/index.php Download image from top of Forum]. {{CodeStart}} '' '' {{Cl|SCREEN}} {{Cl|_NEWIMAGE}}(640, 480, 32) {{Cl|_TITLE}} "Mouse {{Cl|POINT}}er 32" '{{Cl|LINE INPUT}} "Enter an image file: ", image$ 'use quotes around file names with spaces image$ = "QB64bee.png" 'up to 320 X 240 with current {{Cl|_PUTIMAGE}} settings i& = {{Cl|_LOADIMAGE}}(image$, 32) {{Cl|IF...THEN|IF}} i& >= -1 {{Cl|THEN}} {{Cl|BEEP}}: {{Cl|PRINT}} "Could {{Cl|NOT}} load image!": {{Cl|END}} w& = {{Cl|_WIDTH (function)|_WIDTH}}(i&): h& = {{Cl|_HEIGHT}}(i&) {{Cl|PRINT}} "Make background transparent?(Y\N)"; BG$ = {{Cl|UCASE$}}({{Cl|INPUT$}}(1)) {{Cl|PRINT}} BG$ {{Cl|_DELAY}} 1 '{{Cl|CLS}} 'commented to keep background alpha 0 {{Cl|IF...THEN|IF}} BG$ = "Y" {{Cl|THEN}} {{Cl|_CLEARCOLOR}} {{Cl|_RGB32}}(255, 255, 255), i& 'make white Background transparent {{Cl|_PUTIMAGE}} (320 - w&, 240 - h&)-((2 * w&) + (320 - w&), (2 * h&) + (240 - h&)), i&, 0 {{Cl|_FREEIMAGE}} i& {{Cl|_MOUSEMOVE}} 320, 240 'center mouse pointer on screen {{Cl|DO...LOOP|DO}}: {{Cl|_LIMIT}} 100 {{Cl|DO...LOOP|DO}} {{Cl|WHILE}} {{Cl|_MOUSEINPUT}} mx = {{Cl|_MOUSEX}} my = {{Cl|_MOUSEY}} c& = {{Cl|POINT}}(mx, my) r = {{Cl|_RED32}}(c&) g = {{Cl|_GREEN32}}(c&) b = {{Cl|_BLUE32}}(c&) a = {{Cl|_ALPHA32}}(c&) {{Cl|LOCATE}} 1, 1: {{Cl|PRINT}} mx; my, "R:"; r, "G:"; g, "B:"; b, "A:"; a; " " {{Cl|LOCATE}} 2, 2: {{Cl|PRINT}} "HTML Color: {{Cl|&H}}" + {{Cl|RIGHT$}}({{Cl|HEX$}}(c&), 6) {{Cl|LOOP}} {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} > "" {{Cl|END}} '' '' {{CodeEnd}} {{small|Code by Ted Weissgerber}} :''Explanation:'' Use the mouse pointer to get the background RGB of the image to make it transparent with [[_CLEARCOLOR]]. ''Snippet:'' Creating an image mask to PUT an image over other colored backgrounds. See: [[GET and PUT Demo]] to run code. {{TextStart}} FOR c = 0 TO 59 '60 X 60 area from 0 pixel FOR r = 0 TO 59 IF {{Cb|POINT}}(c, r) = 0 THEN {{Cb|PSET}} (c, r), 15 ELSE PSET (c, r), 0 NEXT r NEXT c {{Cb|GET (graphics statement)|GET}}(0, 0)-(60, 60), Image(1500) ' save mask in an array(indexed above original image). {{CodeEnd}} :''Explanation:'' In the procedure all black areas(background) are changed to white for a PUT using AND over other colored objects. The other image colors are changed to black for a PUT of the original image using XOR. The array images can be {{KW|BSAVE}}d for later use. '''QB64 can also''' [[PUT]]''' a full screen 12 image from an array directly into a''' [[BINARY]] '''file.''' ''See Examples:'' * [[SAVEIMAGE]] (QB64 Image to Bitmap SUB by Galleon) * [[Program ScreenShots]] (Member program for legacy screen modes) * [[ThirtyTwoBit SUB]] (QB64 Image area to bitmap) * [[ThirtyTwoBit MEM SUB]] (Fast image area to Bitmap using [[_MEM]]) ''See also:'' * [[_NEWIMAGE]], [[_LOADIMAGE]] {{text|(see 32 bit modes)}} * [[_MEMIMAGE]], [[_MEMGET]] * [[PSET]], [[PRESET]] * [[SCREEN]], [[SCREEN (function)]] {{text|(text pointer function)}} * [[GET (graphics statement)]], [[PUT (graphics statement)]] * [[Bitmaps]], [[Creating Sprite Masks]], [[Text Using Graphics]] (Demo) * [http://www.qb64.net/forum/index.php?topic=11052.0 Reading pixel colors faster using _MEMIMAGE] {{PageNavigation}}