PRINTSTRING: Difference between revisions

Latest revision as of 22:42, 11 February 2023

The _PRINTSTRING statement prints text strings using graphic column and row coordinate positions.

Syntax

_PRINTSTRING(column, row), textExpression$[, imageHandle&]

Parameters

column and row are INTEGER or LONG starting PIXEL (graphic) column and row coordinates to set text or custom fonts.
textExpression$ is any literal or variable string value of text to be displayed.
imageHandle& is the optional image or destination to use. Zero designates current SCREEN page.

Description

The starting coordinate sets the top left corner of the text to be printed. Use _FONTHEIGHT to calculate that text or font position
The _FONT size can affect the screen and row heights.
- Custom fonts are not required. _PRINTSTRING can print all ASCII characters.
_PRINTWIDTH can be used to determine how wide a text print will be so that the screen width is not exceeded.
If the imageHandle& is omitted, the current image, page or screen destination is used.
Can use the current font alpha blending with a designated image background. See the _RGBA function example.
Use the _PRINTMODE statement before printing to set how the background is rendered.
- Use the _PRINTMODE (function) to find the current _PRINTMODE setting.
In SCREEN 0 (text only), _PRINTSTRING works as one-line replacement for LOCATE x, y: PRINT text$, without changing the current cursor position.

Availability

In versions of QB64 prior to 1.000 _PRINTSTRING can only be used in graphic, 256 color or 32 bit screen modes, not SCREEN 0.

Examples

Example 1: Printing those unprintable ASCII control characters is no longer a problem!

SCREEN _NEWIMAGE(800, 600, 256)

FOR code = 0 TO 31
  chrstr$ = chrstr$ + CHR$(code) + SPACE$(1)
NEXT

_FONT _LOADFONT("C:\Windows\Fonts\Cour.ttf", 20, "MONOSPACE") 'select monospace font

_PRINTSTRING (0, 16), chrstr$

END

  ☺ ☻ ♥ ♦ ♣ ♠ • ◘ ○ ◙ ♂ ♀ ♪ ♫ ☼ ► ◄ ↕ ‼ ¶ § ▬ ↨ ↑ ↓ → ← ∟ ↔ ▲ ▼

Example 2: Making any QB64 program window larger using a SUB that easily converts PRINT to _PRINTSTRING.

Scr13& = _NEWIMAGE(320, 200, 13)  'this is the old SCREEN 13 image page to set the image
Big13& = _NEWIMAGE(640, 480, 256) 'use 4 X 3 aspect ratio that QBasic used when full screen

SCREEN Big13&
_DEST Scr13&
image1& = _LOADIMAGE("Howie.BMP", 256)
image2& = _LOADIMAGE("Howie2.BMP", 256)
_PUTIMAGE (10, 20), image1&, Scr13&
_PUTIMAGE (160, 20), image2&, Scr13&
_COPYPALETTE image1&, Scr13&
COLOR 151: LOCATE 2, 4: PRINTS "Screen 13 Height Reduction to 83%"
LOCATE 22, 22: PRINTS CHR$(24) + " 4 X 3 Proportion"  'use concatenation
LOCATE 24, 21: PRINTS CHR$(27) + " Stretched at 100%" 'instead of a semicolon!
_COPYPALETTE Scr13&, Big13&  'required when imported image colors are used
_PUTIMAGE , Scr13&, Big13&   'stretches the screen to double the size
K$ = INPUT$(1)
END

SUB PRINTS (Text$)
row% = (CSRLIN - 1) * _FONTHEIGHT      'finds current screen page text or font row height
col% = (POS(0) - 1) * _PRINTWIDTH("W") 'finds current page text or font column width
_PRINTSTRING (col%, row%), Text$
END SUB

Code by Ted Weissgerber

Explanation: The procedure above creates a larger version of a SCREEN 13 window by stretching it with _PUTIMAGE. It cannot stretch PRINTed text so _PRINTSTRING must be used instead. LOCATE sets the PRINT cursor position for CSRLIN and POS(0) to read. The SUB then converts the coordinates to graphical ones. Then change PRINT to PRINTS using the IDE Search Menu.

Download of Example 2 Bitmap images

Example 3: Rotating a text string around a graphic object.

SCREEN 12
DIM row AS INTEGER, cnt AS INTEGER, cstart AS SINGLE, cend AS SINGLE
DIM xrot AS INTEGER, yrot AS INTEGER, scale AS INTEGER
' _FULLSCREEN                       'full screen optional
cstart = 0: cend = 8 * ATN(1)
xrot = 6: yrot = 60: scale = 4
row = 1
CIRCLE (320, 240), 15, 9: PAINT STEP(0, 0), 9
DO
  FOR i = cstart TO cend STEP .04
    x = 300 + (scale * 40 - (row * xrot)) * COS(i)
    y = 200 + (scale * 40 - (row * yrot)) * SIN(i)
    cnt = cnt + 1
    COLOR 7: _PRINTSTRING (x, y), "HELLO WORLD!", 0  'display
    IF cnt = LEN(text$) * 8 THEN cnt = 0: EXIT DO
    _DISPLAY
    COLOR 0: _PRINTSTRING (x, y), "HELLO WORLD!", 0  'erase
    _DELAY 0.02
  NEXT
LOOP UNTIL INKEY$ = CHR$(27) 'escape key exit
COLOR 15
END

Adapted from code by Unseen Machine

@@ Line 4: / Line 4: @@
 {{PageSyntax}}
 : [[_PRINTSTRING]]({{Parameter|column}}, {{Parameter|row}}), {{Parameter|textExpression$}}[, {{Parameter|imageHandle&}}]
-{{Parameters}}
+{{PageParameters}}
 * {{Parameter|column}} and {{Parameter|row}} are [[INTEGER]] or [[LONG]] starting PIXEL (graphic) column and row coordinates to set text or custom fonts.
 * {{Parameter|textExpression$}} is any literal or variable [[STRING|string]] value of text to be displayed.
-* {{Parameter|imageHandle&}} is the optional image or destination to use. Zero designates current [[SCREEN (statement)|SCREEN]] page.
+* {{Parameter|imageHandle&}} is the optional image or destination to use. Zero designates current [[SCREEN]] page.
 {{PageDescription}}
 * The starting coordinate sets the top left corner of the text to be printed. Use [[_FONTHEIGHT]] to calculate that text or [[_FONT|font]] position
-* The [[_FONT]] size can affect the [[SCREEN (statement)|screen]] and row heights.
+* The [[_FONT]] size can affect the [[SCREEN|screen]] and row heights.
 ** Custom fonts are not required. [[_PRINTSTRING]] can print all [[ASCII]] characters.
 * [[_PRINTWIDTH]] can be used to determine how wide a text print will be so that the screen width is not exceeded.
@@ Line 25: / Line 25: @@
-==Availability==
+{{PageAvailability}}
 * In versions of QB64 prior to 1.000 _PRINTSTRING can only be used in graphic, 256 color or 32 bit screen modes, not SCREEN 0.''
@@ Line 31: / Line 31: @@
 {{PageExamples}}
 ''Example 1:'' Printing those unprintable [[ASCII]] control characters is no longer a problem!
-{{CodeStart}} '' ''
+{{CodeStart}}
 {{Cl|SCREEN}} {{Cl|_NEWIMAGE}}(800, 600, 256)
@@ Line 42: / Line 42: @@
 {{Cl|_PRINTSTRING}} (0, 16), chrstr$
-{{Cl|END}} '' ''
+{{Cl|END}}
 {{CodeEnd}}
 {{OutputStart}}
@@ Line 49: / Line 49: @@
 ''Example 2:'' Making any '''QB64 program window''' larger using a SUB that easily converts PRINT to [[_PRINTSTRING]].
 {{CodeStart}}
 Scr13& = {{Cl|_NEWIMAGE}}(320, 200, 13)  'this is the old SCREEN 13 image page to set the image
-Big13& = {{Cl|_NEWIMAGE}}(640, 480, 256) 'use 4 X 3 aspect ratio that Qbasic used when full screen
+Big13& = {{Cl|_NEWIMAGE}}(640, 480, 256) 'use 4 X 3 aspect ratio that QBasic used when full screen
-{{Cl|SCREEN (statement)|SCREEN}} Big13&
+{{Cl|SCREEN}} Big13&
 {{Cl|_DEST}} Scr13&
 image1& = {{Cl|_LOADIMAGE}}("Howie.BMP", 256)
@@ Line 61: / Line 61: @@
 {{Cl|_PUTIMAGE}} (160, 20), image2&, Scr13&
 {{Cl|_COPYPALETTE}} image1&, Scr13&
 {{Cl|COLOR}} 151: {{Cl|LOCATE}} 2, 4: PRINTS "Screen 13 Height Reduction to 83%"
 {{Cl|LOCATE}} 22, 22: PRINTS {{Cl|CHR$}}(24) + " 4 X 3 Proportion"  'use {{Cl|concatenation}}
 {{Cl|LOCATE}} 24, 21: PRINTS {{Cl|CHR$}}(27) + " Stretched at 100%" 'instead of a {{Cl|semicolon}}!
@@ Line 73: / Line 73: @@
 col% = ({{Cl|POS}}(0) - 1) * {{Cl|_PRINTWIDTH}}("W") 'finds current page text or font column width
 {{Cl|_PRINTSTRING}} (col%, row%), Text$
-{{Cl|END SUB}} '' ''
+{{Cl|END SUB}}
 {{CodeEnd}}
-{{small|Code by Ted Weissgerber}}
+{{Small|Code by Ted Weissgerber}}
 : ''Explanation:'' The procedure above creates a larger version of a SCREEN 13 window by stretching it with [[_PUTIMAGE]]. It cannot stretch PRINTed text so [[_PRINTSTRING]] must be used instead. [[LOCATE]] sets the PRINT cursor position for [[CSRLIN]] and [[POS]](0) to read. The SUB then converts the coordinates to graphical ones. Then '''change''' [[PRINT]] to PRINTS using the IDE '''Search Menu'''.
 <center>[https://www.dropbox.com/s/tcdik1ajegbeiz4/HOWIE.zip?dl=0 Download of Example 2 Bitmap images]</center>
@@ Line 81: / Line 81: @@
 ''Example 3:'' Rotating a text string around a graphic object.
-{{CodeStart}} '' ''
+{{CodeStart}}
-{{Cl|SCREEN (statement)|SCREEN}} 12 '' ''
+{{Cl|SCREEN}} 12
 {{Cl|DIM}} row {{Cl|AS}} {{Cl|INTEGER}}, cnt {{Cl|AS}} {{Cl|INTEGER}}, cstart {{Cl|AS}} {{Cl|SINGLE}}, cend {{Cl|AS}} {{Cl|SINGLE}}
 {{Cl|DIM}} xrot {{Cl|AS}} {{Cl|INTEGER}}, yrot {{Cl|AS}} {{Cl|INTEGER}}, scale {{Cl|AS}} {{Cl|INTEGER}}
 ' {{Cl|_FULLSCREEN}}                       'full screen optional
 cstart = 0: cend = 8 * {{Cl|ATN}}(1)
 xrot = 6: yrot = 60: scale = 4
 row = 1
 {{Cl|CIRCLE}} (320, 240), 15, 9: {{Cl|PAINT}} {{Cl|STEP}}(0, 0), 9
@@ Line 95: / Line 95: @@
      y = 200 + (scale * 40 - (row * yrot)) * {{Cl|SIN}}(i)
      cnt = cnt + 1
      {{Cl|COLOR}} 7: {{Cl|_PRINTSTRING}} (x, y), "HELLO WORLD!", 0  'display
      {{Cl|IF}} cnt = {{Cl|LEN}}(text$) * 8 {{Cl|THEN}} cnt = 0: {{Cl|EXIT DO}}
      {{Cl|_DISPLAY}}
      {{Cl|COLOR}} 0: {{Cl|_PRINTSTRING}} (x, y), "HELLO WORLD!", 0  'erase
      {{Cl|_DELAY}} 0.02
    {{Cl|NEXT}}
 {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27) 'escape key exit
 {{Cl|COLOR}} 15
-{{Cl|END}} '' ''
+{{Cl|END}}
 {{CodeEnd}}
-{{small|Adapted from code by Unseen Machine}}
+{{Small|Adapted from code by Unseen Machine}}
 {{PageSeeAlso}}
 * [[_NEWIMAGE]], [[_PRINTWIDTH]], [[_PRINTMODE]]
-* [[_CONTROLCHR]] {{text|(turns [[ASCII]] control characters OFF or ON)}}
+* [[_CONTROLCHR]]
 * [[_FONT]], [[_LOADFONT]], [[_FONTHEIGHT]], [[_FONTWIDTH]]
 * [[_SCREENIMAGE]], [[_SCREENPRINT]]