Difference between revisions of "LOADIMAGE"

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''Example 4:'' Rotating an image 360 degrees using [[DRAW]] and Turn Angle.
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''Example 4:'' [[DRAW]]ing and rotating an image 360 degrees using Turn Angle. [[POINT]] is used to read the invisible image source.
 
{{CodeStart}}
 
{{CodeStart}}
 
{{Cl|SCREEN (statement)|SCREEN}} {{Cl|_NEWIMAGE}}(800, 600, 32)
 
{{Cl|SCREEN (statement)|SCREEN}} {{Cl|_NEWIMAGE}}(800, 600, 32)
  
img& = {{Cl|_LOADIMAGE}}("QB64bee.PNG")
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img& = {{Cl|_LOADIMAGE}}("QB64.PNG")                           'load the image file to be drawn
 
wide% = {{Cl|_WIDTH (function)|_WIDTH}}(img&): deep% = {{Cl|_HEIGHT}}(img&)
 
wide% = {{Cl|_WIDTH (function)|_WIDTH}}(img&): deep% = {{Cl|_HEIGHT}}(img&)
TLC$ = "BL" + {{Cl|STR$}}(wide% \ 2) + "BU" + {{Cl|STR$}}(deep% \ 2)
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TLC$ = "BL" + {{Cl|STR$}}(wide% \ 2) + "BU" + {{Cl|STR$}}(deep% \ 2) 'start draw at top left corner
RET$ = "BD BL" + {{Cl|STR$}}(wide%)
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RET$ = "BD BL" + {{Cl|STR$}}(wide%)                           'return to left side of image
 
{{Cl|_SOURCE}} img&
 
{{Cl|_SOURCE}} img&
 
{{Cl|_DEST}} 0
 
{{Cl|_DEST}} 0
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     {{Cl|FOR...NEXT|FOR}} y = 0 {{Cl|TO}} deep% - 1
 
     {{Cl|FOR...NEXT|FOR}} y = 0 {{Cl|TO}} deep% - 1
 
       {{Cl|FOR...NEXT|FOR}} x = 0 {{Cl|TO}} wide% - 1
 
       {{Cl|FOR...NEXT|FOR}} x = 0 {{Cl|TO}} wide% - 1
         {{Cl|DRAW}} "C" + {{Cl|STR$}}({{Cl|POINT}}(x, y)) + " R1"
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         {{Cl|DRAW}} "C" + {{Cl|STR$}}({{Cl|POINT}}(x, y)) + "R1"           'color and DRAW each pixel
 
       {{Cl|NEXT}}
 
       {{Cl|NEXT}}
 
       {{Cl|DRAW}} RET$
 
       {{Cl|DRAW}} RET$
 
     {{Cl|NEXT}}
 
     {{Cl|NEXT}}
     {{Cl|_DISPLAY}}
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     {{Cl|_DISPLAY}}                         'NOTE: CPU usage will be HIGH!
 
   {{Cl|NEXT}}
 
   {{Cl|NEXT}}
 
{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} > "" '' ''
 
{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} > "" '' ''
 
{{CodeEnd}}
 
{{CodeEnd}}
 
{{small|Code by Ted Weissgerber}}
 
{{small|Code by Ted Weissgerber}}
:''NOTE:'' The ''QB64.PNG'' file picturing the QB64 bee can saved from the top of the QB64 forum.
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:''NOTE:'' The ''QB64.PNG'' file picturing the QB64 bee can saved from the top of the [http://www.qb64.net/forum/index.php QB64 forum]. Speed varies with image size.
 +
 
  
 
''See Examples:''
 
''See Examples:''

Revision as of 00:57, 27 February 2011

The _LOADIMAGE function loads an image into memory and returns an image handle for a graphic file image.


Syntax

handle& = _LOADIMAGE& (filename$[, mode&])


Description

  • File types supported: BMP, JPG, PNG, GIF, PNM, XPM, XCF, PCX, TIF, LBM, and TGA. A path can also be given.
  • The Mode& can designate 256(8 bit) or 32 bit color. Omit to use the current screen settings.
  • Some images may not load when a mode value is designated. Try loading it without a mode designation.
  • Loaded images can be read invisibly using POINT. Image coordinates start at 0 up to the _WIDTH - 1 and _HEIGHT - 1.
  • Images can be made into a program SCREEN or page adopting the size and palette settings or placed using _PUTIMAGE.
  • When you are in SCREEN 0 a mode& must be designated. When loading an _ICON use 32 for the mode.
  • Returns -1 as an invalid handle if it could not load the image. Valid LONG handle returns are less than -1.
  • Valid images only need to be loaded ONCE! The handle can be used repeatedly until freed.
  • It is IMPORTANT to free unused or discarded images with _FREEIMAGE to prevent CPU memory overflow errors!


Examples

Example 1: Already in SCREEN 13 and want computer to match the 32-bit jpg/etc. colors to the current palette:

SCREEN 13 i& = _LOADIMAGE("mypic.jpg") _PUTIMAGE, i&


Example 2: Already in SCREEN 13 but want to load an 8-bit image and adopt its palette as the current palette:

SCREEN 13 i& = _LOADIMAGE("mypic256col.bmp", 256) _COPYPALETTE i&, 0 _PUTIMAGE, i&


Example 3: Want to display an image in 32-bit color using its resolution as a program screen:

i& = _LOADIMAGE("mypic.jpg", 32) SCREEN i&


Example 4: DRAWing and rotating an image 360 degrees using Turn Angle. POINT is used to read the invisible image source.

SCREEN _NEWIMAGE(800, 600, 32) img& = _LOADIMAGE("QB64.PNG") 'load the image file to be drawn wide% = _WIDTH(img&): deep% = _HEIGHT(img&) TLC$ = "BL" + STR$(wide% \ 2) + "BU" + STR$(deep% \ 2) 'start draw at top left corner RET$ = "BD BL" + STR$(wide%) 'return to left side of image _SOURCE img& _DEST 0 DO FOR angle% = 0 TO 360 STEP 15 CLS DRAW "BM400, 300" + "TA=" + VARPTR$(angle%) + TLC$ FOR y = 0 TO deep% - 1 FOR x = 0 TO wide% - 1 DRAW "C" + STR$(POINT(x, y)) + "R1" 'color and DRAW each pixel NEXT DRAW RET$ NEXT _DISPLAY 'NOTE: CPU usage will be HIGH! NEXT LOOP UNTIL INKEY$ > ""

Code by Ted Weissgerber
NOTE: The QB64.PNG file picturing the QB64 bee can saved from the top of the QB64 forum. Speed varies with image size.


See Examples:

  • SAVEIMAGE (QB64 Image to Bitmap SUB by Galleon)


See also



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