Smalltalk80LanguageImplementation:Chapter 18 - Revision history

Onionmixer: 오타수정

2015-07-13T00:57:29Z

오타수정

← Older revision		Revision as of 00:57, 13 July 2015
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	The message drawFrom: startPoint to: stopPoint stores the destX and destY values. Starting from these stored values, the line-drawing loop, drawLoopX: xDelta Y: yDelta, shown next, accepts x and y delta values and calculates x and y step values to determine points along the line, and then calls copyBits in order to display the appropriate image at each point. The method used is the Bresenham plotting algorithm (IBM Systems Journal, Volume 4, Number 1, 1965). It chooses a principal direction and maintains a variable, p When p's sign changes, it is time		The message drawFrom: startPoint to: stopPoint stores the destX and destY values. Starting from these stored values, the line-drawing loop, drawLoopX: xDelta Y: yDelta, shown next, accepts x and y delta values and calculates x and y step values to determine points along the line, and then calls copyBits in order to display the appropriate image at each point. The method used is the Bresenham plotting algorithm (IBM Systems Journal, Volume 4, Number 1, 1965). It chooses a principal direction and maintains a variable, p When p's sign changes, it is time to move in the minor direction as well. This method is a natural unit to be implemented as a primitive method, since the computation is trivial and the setup in copyBits is almost all constant from one invocation to the next.


	to move in the minor direction as well. This method is a natural unit to be implemented as a primitive method, since the computation is trivial and the setup in copyBits is almost all constant from one invocation to the next.

Onionmixer: 정오표 수정

2014-05-09T09:35:25Z

정오표 수정

← Older revision		Revision as of 09:35, 9 May 2014
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	\|- style="vertical-align:top;"		\|- style="vertical-align:top;"
	\|<syntaxhighlight lang="smalltalk">		\|<syntaxhighlight lang="smalltalk">
	~~Biblt~~ class protocol		BitBlt class protocol
	instance creationg		instance creationg
	destForm: destination		destForm: destination
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	The ~~BitBit~~ protocol includes the messages drawFrom: startPoint to: stopPoint to draw a line whose end points are the arguments, startPoint and stopPoint.		The BitBlt protocol includes the messages drawFrom: startPoint to: stopPoint to draw a line whose end points are the arguments, startPoint and stopPoint.

	{\| style="border: 1px solid black;"		{\| style="border: 1px solid black;"
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	The message drawFrom: startPoint to: stopPoint stores the destX and destY values. Starting from these stored values, the line-drawing loop, drawLoopX: ~~xDeita~~ Y: ~~yDeita~~, shown next, accepts x and y delta values and calculates x and y step values to determine points along the line, and then calls copyBits in order to display the appropriate image at each point. The method used is the Bresenham plotting algorithm (IBM Systems Journal, Volume 4, Number 1, 1965). It chooses a principal direction and maintains a variable, p When p's sign changes, it is time		The message drawFrom: startPoint to: stopPoint stores the destX and destY values. Starting from these stored values, the line-drawing loop, drawLoopX: xDelta Y: yDelta, shown next, accepts x and y delta values and calculates x and y step values to determine points along the line, and then calls copyBits in order to display the appropriate image at each point. The method used is the Bresenham plotting algorithm (IBM Systems Journal, Volume 4, Number 1, 1965). It chooses a principal direction and maintains a variable, p When p's sign changes, it is time


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	Special cases can be provided for 2 if the operation is a simple store or a simple copy with no skew (horizontal bit offset) from source to destination. In this way, most macroscopic applications of ~~BitBit can~~ be made fast, even on processors of modest power.		Special cases can be provided for 2 if the operation is a simple store or a simple copy with no skew (horizontal bit offset) from source to destination. In this way, most macroscopic applications of BitBlt cab be made fast, even on processors of modest power.

Onionmixer: SMALLTALK80 Chapter 18 Graphics Kernel 페이지 추가

2014-04-24T06:18:58Z

SMALLTALK80 Chapter 18 Graphics Kernel 페이지 추가

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