Programming AmigaOS 4: Drawing Graphics - Revision history

Costel Mincea: Text replacement - "" to ""

2025-01-26T19:09:45Z

Text replacement - "<syntaxhighlight>" to "<syntaxhighlight lang="C" line>"

← Older revision		Revision as of 19:09, 26 January 2025
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	After all this theory now a practical side as well. As long as the text is simply displayed on the screen, IGraphics->Move() and IGraphics->Text will suffice. As the case may be also an IDiskfont->OpenDiskFont() and IGraphics->SetFont() for opening and using the font. All well-known ones function. Should however the single characters be rotated, clinched or use a different character spacing, things get a little more interesting. All this can be simply realised with the new functions of diskfont.library. One requirement, however, is that it is a scalable font. It will not function with the "old" bitmap fonts. Before we can get going, we first have to open the FontEngine. The available Engines are presented below.		After all this theory now a practical side as well. As long as the text is simply displayed on the screen, IGraphics->Move() and IGraphics->Text will suffice. As the case may be also an IDiskfont->OpenDiskFont() and IGraphics->SetFont() for opening and using the font. All well-known ones function. Should however the single characters be rotated, clinched or use a different character spacing, things get a little more interesting. All this can be simply realised with the new functions of diskfont.library. One requirement, however, is that it is a scalable font. It will not function with the "old" bitmap fonts. Before we can get going, we first have to open the FontEngine. The available Engines are presented below.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	struct EGlyphEngine EEngine;		struct EGlyphEngine EEngine;

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	And at the end of the program we of course have to close the FontEngine again.		And at the end of the program we of course have to close the FontEngine again.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	IDiskfont->ECloseEngine(&EEngine);		IDiskfont->ECloseEngine(&EEngine);
	}		}
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	The different actions and the desired characters are set using IDiskfont->ESetInfo(). Everything is OK when the returncode is 0.		The different actions and the desired characters are set using IDiskfont->ESetInfo(). Everything is OK when the returncode is 0.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	if(!(error = IDiskfont->ESetInfo(EEngine,		if(!(error = IDiskfont->ESetInfo(EEngine,
	OT_PointHeight, 20, /* Zeichenhˆhe in Pixel */		OT_PointHeight, 20, /* Zeichenhˆhe in Pixel */
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	This completes the preparation of the data and it can also be read using IDiskfont->EObtainInfo(). The data can be transferred to the screen as well with IGraphics->BliBitMapXXX.		This completes the preparation of the data and it can also be read using IDiskfont->EObtainInfo(). The data can be transferred to the screen as well with IGraphics->BliBitMapXXX.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	struct GlyphMap glyph;		struct GlyphMap glyph;
	if(!(error = IDiskfont->EObtainInfo(EEngine,		if(!(error = IDiskfont->EObtainInfo(EEngine,
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	As this short excerpt already shows the BitMap data of the character is available in the GlyphMap structure and can be directly blitted to the window.. Using IDiskFont->EReleaseInfo() the loaded resources are released at the end. The complete source code with all dependencies can be found under "FontViewer.c". This also uses ReAction-gadgets which we will cover in a future edition.		As this short excerpt already shows the BitMap data of the character is available in the GlyphMap structure and can be directly blitted to the window.. Using IDiskFont->EReleaseInfo() the loaded resources are released at the end. The complete source code with all dependencies can be found under "FontViewer.c". This also uses ReAction-gadgets which we will cover in a future edition.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	/* Michael Christoph		/* Michael Christoph
	* FontViewer.c		* FontViewer.c

Steven Solie: /* Everything standardised */

2016-09-24T20:18:38Z

Everything standardised

@@ Line 737: / Line 737: @@
 We can thank the "European Computer Manufacturer's Association" (ECMA) for worldwide standardisation of the character sets under ISO-8859 and thus giving AmigaOS 4 a chance to display the correct characters on the screen by loading the correct font for it.
- ISO 8859-2    Central and Eastern European languages (Latin-2, Croatian, Polish, Slovakian, Czech, Hungarian and others)
+| ISO 8859-1 || Western European languages (Latin-1, German, English, French, Danish, Spanish and others)
- ISO 8859-4    Scandinavian/Baltic languages(Latin-4, Estonian, Latvian, Lithuanian)
+| ISO 8859-2 || Central and Eastern European languages (Latin-2, Croatian, Polish, Slovakian, Czech, Hungarian and others)
- ISO 8859-6    Latin/Arabic (Arabic script)
+| ISO 8859-3 || South European languages (Latin-3, Turkish)
- ISO 8859-10   Lappish/Nordic/Eskimo languages (Latin-6)
+| ISO 8859-5 || Latin/Cyrillic (Cyrillic script)
- ISO 8859-13   Baltic languages (Latin-7)
+| ISO 8859-6 || Latin/Arabic (Arabic script)
- ISO 8859-15   Western European languages (Latin-9 with Euro-symbol)
+| ISO 8859-7 || Latin/Greek (New-Greek script)
 = Authors =

Steven Solie: /* Everything standardised */

2016-09-24T20:15:14Z

Everything standardised

← Older revision		Revision as of 20:15, 24 September 2016
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	We can thank the "European Computer Manufacturer's Association" (ECMA) for worldwide standardisation of the character sets under ISO-8859 and thus giving AmigaOS 4 a chance to display the correct characters on the screen by loading the correct font for it.		We can thank the "European Computer Manufacturer's Association" (ECMA) for worldwide standardisation of the character sets under ISO-8859 and thus giving AmigaOS 4 a chance to display the correct characters on the screen by loading the correct font for it.

	ISO 8859-1 Western European languages (Latin-1, German, English,		ISO 8859-1 Western European languages (Latin-1, German, English, French, Danish, Spanish and others)
	~~French~~, ~~Danish~~, ~~Spanish~~ and others)		ISO 8859-2 Central and Eastern European languages (Latin-2, Croatian, Polish, Slovakian, Czech, Hungarian and others)
	ISO 8859-2 Central and Eastern European languages (Latin-2, Croatian,
	Polish, Slovakian, Czech, Hungarian and others)
	ISO 8859-3 South European languages (Latin-3, Turkish)		ISO 8859-3 South European languages (Latin-3, Turkish)
	ISO 8859-4 Scandinavian/Baltic languages(Latin-4, Estonian,		ISO 8859-4 Scandinavian/Baltic languages(Latin-4, Estonian, Latvian, Lithuanian)
	Latvian, Lithuanian)
	ISO 8859-5 Latin/Cyrillic (Cyrillic script)		ISO 8859-5 Latin/Cyrillic (Cyrillic script)
	ISO 8859-6 Latin/Arabic (Arabic script)		ISO 8859-6 Latin/Arabic (Arabic script)

Steven Solie: /* Transparent */

2016-09-24T20:13:47Z

Transparent

← Older revision		Revision as of 20:13, 24 September 2016
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	[[File:AF107_FontViewer_grab.png\|frame\|center]]		[[File:AF107_FontViewer_grab.png\|frame\|center]]

	= Transparent =

	You can already look forward to the next edition, in which we will deal a bit more with the graphics, even when you don't see anything with transparency. This means the new options of the Cairo-library, with which you can, for example, realise borderless windows, or make the content underneath the window (partly) transparent.

	= New functions in the diskfont.library V50 =		= New functions in the diskfont.library V50 =

Steven Solie: /* Direct layout */

2016-09-24T20:11:16Z

Direct layout

Show changes

Steven Solie: /* Transparent */

2016-09-02T02:55:48Z

Transparent

← Older revision		Revision as of 02:55, 2 September 2016
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	You can already look forward to the next edition, in which we will deal a bit more with the graphics, even when you don't see anything with transparency. This means the new options of the Cairo-library, with which you can, for example, realise borderless windows, or make the content underneath the window (partly) transparent.		You can already look forward to the next edition, in which we will deal a bit more with the graphics, even when you don't see anything with transparency. This means the new options of the Cairo-library, with which you can, for example, realise borderless windows, or make the content underneath the window (partly) transparent.

		⚫	= New functions in the diskfont.library V50 =
	-----------------------------------------------------------------------------
⚫	~~[*** Kasten]~~ New functions in the diskfont.library V50:

	[***first the declaration, underneath one or two lines of the prototype]
	Opening and closing a scalable font		Opening and closing a scalable font
	struct OutlineFont OpenOutlineFont(STRPTR fileName, struct List list, ULONG flags);		struct OutlineFont OpenOutlineFont(STRPTR fileName, struct List list, ULONG flags);
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	VOID FreeTTextAttr(struct TTextAttr *tta);		VOID FreeTTextAttr(struct TTextAttr *tta);

		⚫	= New functions in graphics.library V51 =
	-----------------------------------------------------------------------------
⚫	~~[*** Kasten]~~ New functions in graphics.library V51:

	Composing two bitmaps together:		Composing two bitmaps together:
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	int32 BltBitMapTags(uint32 tag, ...)		int32 BltBitMapTags(uint32 tag, ...)

		⚫	= Font engines =
	------------------------------------------------------------------------------

		⚫	If you wanted to support different fonts in your own program in the past there were different libraries with their own installation programs for that in the past. AmigaOS 4 unifies them all in the diskfont.library.
⚫	~~[*** Kasten]~~ Font engines
⚫	If you wanted to support different fonts in your own program in the past there were different libraries with their own installation programs for that in the past. ~~AmigaOS4~~ unifies them all in the diskfont.library.

			{\| class="wikitable"

	Library ~~Installationprogram~~ Supported Font ~~formats~~		! Library !! Installation Program !! Supported Font Formats
			\|-
	bullet.library Intellifont CompuGraphic		\| bullet.library \|\| Intellifont \|\| CompuGraphic
⚫	type1.library T1Manager PostScript type 1
			\|-
⚫	ttf.library TTFManager TrueType
		⚫	\| type1.library \|\| T1Manager \|\| PostScript type 1
⚫	ft2.library TypeManager ~~AmigaOS4~~: CG, PS, TT, and others
			\|-

		⚫	\| ttf.library \|\| TTFManager \|\| TrueType
	------------------------------------------------------------------------------
			\|-
		⚫	\| ft2.library \|\| TypeManager \|\| AmigaOS 4: CG, PS, TT and others
			\|}

	= Everything standardised =		= Everything standardised =

Steven Solie: /* Transparent */

2016-09-02T02:51:58Z

Transparent

← Older revision		Revision as of 02:51, 2 September 2016
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	------------------------------------------------------------------------------		------------------------------------------------------------------------------

	[*** ~~Kasten]everything~~ standardised		= Everything standardised =

	We can thank the "European Computer Manufacturer's Association" (ECMA) for worldwide standardisation of the character sets under ISO-8859 and thus giving ~~AmigaOS4~~ a chance to display the correct characters on the screen by loading the correct font for it.		We can thank the "European Computer Manufacturer's Association" (ECMA) for worldwide standardisation of the character sets under ISO-8859 and thus giving AmigaOS 4 a chance to display the correct characters on the screen by loading the correct font for it.

	ISO 8859-1 Western European languages (Latin-1, German, English,		ISO 8859-1 Western European languages (Latin-1, German, English,
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	ISO 8859-15 Western European languages (Latin-9 with Euro-symbol)		ISO 8859-15 Western European languages (Latin-9 with Euro-symbol)
	ISO 8859-16 Eastern European languages (Latin-10)		ISO 8859-16 Eastern European languages (Latin-10)

	---------------------------------------

	= Authors =		= Authors =

Steven Solie: /* Direct layout */

2016-09-02T02:50:14Z

Direct layout

← Older revision		Revision as of 02:50, 2 September 2016
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	}		}
	</syntaxhighlight>		</syntaxhighlight>

			[[File:AF107_FontViewer_grab.png\|frame\|center]]

	= Transparent =		= Transparent =

Steven Solie: /* Direct layout */

2016-09-02T02:49:22Z

Direct layout

Show changes

Steven Solie: /* Graphics library */

2016-09-02T02:46:48Z

Graphics library

← Older revision		Revision as of 02:46, 2 September 2016
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	Basically speaking the layers.library deals with the organisation of data, and intuition, on the other hand, takes care of the interaction with the user. In between is the graphics.library and it deals with the display of data on screen. AmigaOS 4.0 includes the Picasso driver system (albeit in PPC native form). AmigaOS 4.1 introduces a new graphics.library API which replaces the Picasso driver system. New options have resulted in the compositing that was introduced in AmigaOS 4.1. This allows the "real" transparent areas in windows and window decorations.		Basically speaking the layers.library deals with the organisation of data, and intuition, on the other hand, takes care of the interaction with the user. In between is the graphics.library and it deals with the display of data on screen. AmigaOS 4.0 includes the Picasso driver system (albeit in PPC native form). AmigaOS 4.1 introduces a new graphics.library API which replaces the Picasso driver system. New options have resulted in the compositing that was introduced in AmigaOS 4.1. This allows the "real" transparent areas in windows and window decorations.

	* Layers in background		= Layers in background =

	Normal applications do not need to access the functions of layers.library directly, that perform their task in the "background". Many of the higher OS functions of Intuition and Datatypes however do. They deal with the organisation of the screen area and for an optimal refresh, in case only the needed parts for drawing something are released. On the other side, it is also possible to define clip-ranges yourself and all draw functions outside that area are ignored. This makes it, for instance, possible to prevent text from flowing over the right hand side of the window (or any other area).		Normal applications do not need to access the functions of layers.library directly, that perform their task in the "background". Many of the higher OS functions of Intuition and Datatypes however do. They deal with the organisation of the screen area and for an optimal refresh, in case only the needed parts for drawing something are released. On the other side, it is also possible to define clip-ranges yourself and all draw functions outside that area are ignored. This makes it, for instance, possible to prevent text from flowing over the right hand side of the window (or any other area).
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	New are the functions ILayer->ShowLayer() and ILayers->HideLayer(), which have already demonstrated their practicality in the last part of our workshop when used with IIntuition->ShowWindow() and IIntuition->HideWindow(). The fill of a background areas is easier to automate as well. Those interested are referred to the functions ILayers->CreateBackFillHook() and ILayers->DeleteBackFillHook(), as well as ILayers->SetBackFillHookAttrs() and Ilayers->GetBackFillHookAttrs().		New are the functions ILayer->ShowLayer() and ILayers->HideLayer(), which have already demonstrated their practicality in the last part of our workshop when used with IIntuition->ShowWindow() and IIntuition->HideWindow(). The fill of a background areas is easier to automate as well. Those interested are referred to the functions ILayers->CreateBackFillHook() and ILayers->DeleteBackFillHook(), as well as ILayers->SetBackFillHookAttrs() and Ilayers->GetBackFillHookAttrs().

	* Fonts		= Fonts =

	It all gets much more interesting however when we get to fonts, which are also displayed on screen by graphics.library (With the IGraphics->Text() function). Just this once we will deal with the Workbench. The old IntelliFont Installation Program has been sent for retirement and replaced by FontManager. This program allows installing new fonts for the Amiga. This is necessary because of certain information posted in the .font files (for bitmap fonts) or for example .otag files (scaled fonts). The former well known Agfa Intelli-fonts are still supported by FontManager as well, even though there are hardly fonts available in this format. It gets more interesting with the TrueType fonts from the PC scene and the from the printer realm originating PostScript (Type1) fonts. This is not enough for FontManager. Other, rather unknown font formats, are supported as well, like for example OpenType fonts.		It all gets much more interesting however when we get to fonts, which are also displayed on screen by graphics.library (With the IGraphics->Text() function). Just this once we will deal with the Workbench. The old IntelliFont Installation Program has been sent for retirement and replaced by FontManager. This program allows installing new fonts for the Amiga. This is necessary because of certain information posted in the .font files (for bitmap fonts) or for example .otag files (scaled fonts). The former well known Agfa Intelli-fonts are still supported by FontManager as well, even though there are hardly fonts available in this format. It gets more interesting with the TrueType fonts from the PC scene and the from the printer realm originating PostScript (Type1) fonts. This is not enough for FontManager. Other, rather unknown font formats, are supported as well, like for example OpenType fonts.

	As soon as the fonts are initialised on the system with the Typemanager it doesn't make any difference from the programs point of view what the type of the font actually is. If it is set in the configuration they are even displayed anti-aliased, this means with smoothed sides. The setting for this is found in the "Font-Prefs" settings program.		As soon as the fonts are initialised on the system with the Typemanager it doesn't make any difference from the programs point of view what the type of the font actually is. If it is set in the configuration they are even displayed anti-aliased, this means with smoothed sides. The setting for this is found in the "Font-Prefs" settings program.

			[[File:AF107_prefs-font_eng.png\|frame\|center]]

	In case more information is needed about individual characters, all important functions for this are available from the bullet.library are now directly available in the diskfont.library. The font specific libraries (bullet, type1 or ttf) are not to be used anymore !		In case more information is needed about individual characters, all important functions for this are available from the bullet.library are now directly available in the diskfont.library. The font specific libraries (bullet, type1 or ttf) are not to be used anymore !

	* Encoding Warning		= Encoding Warning =

	~~AmigaOS4~~ now supports different encoding tables as well. The ISO 8859-1 (latin 1) table was valid for Western Europe for a long time for example. It has been replaced by the 15x tables (Latin 9) with the introduction of the Euro. For Central Europe -2 is used, for Greece -7 etc.		AmigaOS 4 now supports different encoding tables as well. The ISO 8859-1 (latin 1) table was valid for Western Europe for a long time for example. It has been replaced by the 15x tables (Latin 9) with the introduction of the Euro. For Central Europe -2 is used, for Greece -7 etc.

	While the first 128 characters of the ASCII table are uniform worldwide, the upper 128 bytes (value 128-255) can be assigned differently		While the first 128 characters of the ASCII table are uniform worldwide, the upper 128 bytes (value 128-255) can be assigned differently
	This is the range where country specific special characters like "?? can be found. With ~~OS4~~ it is possible to set which encoding should be used in the Locale preferences. When a font is opened the associated encoding is automatically looked up. If no suitable font is found it will look for one without encoding information. If both of those should fail, opening the font fails. Fonts with the same name but different encoding are not used under any circumstances. This all happens automatically again. Programming wise there is nothing extra to code for.		This is the range where country specific special characters like "?? can be found. With AmigaOS 4 it is possible to set which encoding should be used in the Locale preferences. When a font is opened the associated encoding is automatically looked up. If no suitable font is found it will look for one without encoding information. If both of those should fail, opening the font fails. Fonts with the same name but different encoding are not used under any circumstances. This all happens automatically again. Programming wise there is nothing extra to code for.

			[[File:AF107_prefs-locale_eng.png\|frame\|center]]

	This does however have one drawback, because as a programmer you can not predict anymore what character hides within ASCII-Code 168 for example. Normally you would find the copyright symbol "?" there. This often used character should therefore be replaced by "(c)".		This does however have one drawback, because as a programmer you can not predict anymore what character hides within ASCII-Code 168 for example. Normally you would find the copyright symbol "?" there. This often used character should therefore be replaced by "(c)".
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	The encoding is of course valid as well for the catalog file. Here it is just a case of writing the right "codeset" Tag in the CatalogTranslation-File (.ct). The rest is again taken care of by the operating system.		The encoding is of course valid as well for the catalog file. Here it is just a case of writing the right "codeset" Tag in the CatalogTranslation-File (.ct). The rest is again taken care of by the operating system.

			There is an ongoing effort to switch to Unicode and use UTF-8 but it will be a while until those features are implemented fully.
	There have been discussions about the need for an implementation of Unicode in the past, but until today there is nothing to expect from it. In Unicode a character is represented by 16 Bit or two bytes, this results in a character reserve from 0 to 65535. All the possible special characters correspondingly have a set place (ID) and there is only one code table. For programmers this would however be a big switch, because then one character is not represented by one character but by two.

	* Direct layout		= Direct layout =

	After all this theory now a practical side as well. As long as the text is simply displayed on the screen, IGraphics->Move() and IGraphics->Text will suffice. As the case may be also an IDiskfont->OpenDiskFont() and IGraphics->SetFont() for opening and using the font. All well-known ones function. Should however the single characters be rotated, clinched or use a different character spacing, things get a little more interesting. All this can be simply realised with the new functions of diskfont.library. One requirement, however, is that it is a scalable font. It will not function with the "old" bitmap fonts. Before we can get going, we first have to open the FontEngine. The available Engines are presented below.		After all this theory now a practical side as well. As long as the text is simply displayed on the screen, IGraphics->Move() and IGraphics->Text will suffice. As the case may be also an IDiskfont->OpenDiskFont() and IGraphics->SetFont() for opening and using the font. All well-known ones function. Should however the single characters be rotated, clinched or use a different character spacing, things get a little more interesting. All this can be simply realised with the new functions of diskfont.library. One requirement, however, is that it is a scalable font. It will not function with the "old" bitmap fonts. Before we can get going, we first have to open the FontEngine. The available Engines are presented below.
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	---------------------------------------		---------------------------------------


	= Authors =		= Authors =