Rasters - Revision history

Polluks: typo

2012-01-03T14:13:56Z

typo

← Older revision		Revision as of 14:13, 3 January 2012
Line 27:		Line 27:


	==~~Exemples~~ of Raster effect in Games==		==Examples of Raster effect in Games==
	*Some GX4000 games are CPC games which include Rasters effect to add colours.		*Some GX4000 games are CPC games which include Rasters effect to add colours.
	**Crazy Car 2 : extra colours layer in the sky.		**Crazy Car 2 : extra colours layer in the sky.
Line 37:		Line 37:
	Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.		Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.

	==~~Exemples~~ of Raster Effect in ~~Demo~~==		==Examples of Raster Effect in Demos==

	==Links==		==Links==

CPCLER: /* Exemples of Raster effect in Games */

2009-10-14T15:47:51Z

Exemples of Raster effect in Games

← Older revision		Revision as of 15:47, 14 October 2009
Line 33:		Line 33:
	**Switchblade : also a good Red layer.		**Switchblade : also a good Red layer.

	*[Striker in the Crypts of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).		*[[Striker in the Crypts of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).
	This games looks a lot like Switchblade indeed...It is a mod of the Switchblade engine.		This games looks a lot like Switchblade indeed...It is a mod of the Switchblade engine.
	Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.		Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.

CPCLER at 15:47, 14 October 2009

2009-10-14T15:47:38Z

← Older revision		Revision as of 15:47, 14 October 2009
Line 33:		Line 33:
	**Switchblade : also a good Red layer.		**Switchblade : also a good Red layer.

	*[[Striker ~~In The~~ Crypts Of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).		*[Striker in the Crypts of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).
	This games looks a lot like Switchblade indeed...It is a mod of the Switchblade engine.		This games looks a lot like Switchblade indeed...It is a mod of the Switchblade engine.
	Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.		Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.

MacDeath: /* Links */

2009-10-14T13:38:23Z

Links

← Older revision		Revision as of 13:38, 14 October 2009
Line 42:		Line 42:

	*[http://en.wikipedia.org/wiki/Raster Wikipedia link to Raster concepts]		*[http://en.wikipedia.org/wiki/Raster Wikipedia link to Raster concepts]
			*[http://en.wikipedia.org/wiki/Raster_interrupt Wikipedia on Raster-interrupt]

	==CPCWiki Links==		==CPCWiki Links==

MacDeath: /* Exemples of Raster effect in Games */

2009-10-14T13:37:35Z

Exemples of Raster effect in Games

← Older revision		Revision as of 13:37, 14 October 2009
Line 34:		Line 34:

	*[[Striker In The Crypts Of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).		*[[Striker In The Crypts Of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).
	This games looks a lot like Switchblade indeed...It ~~may be~~ a mod of the Switchblade engine.		This games looks a lot like Switchblade indeed...It is a mod of the Switchblade engine.
	Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.		Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.

Arnoldemu at 13:33, 14 October 2009

2009-10-14T13:33:40Z

← Older revision		Revision as of 13:33, 14 October 2009
Line 9:		Line 9:

	It is also a good technic to display very coloured layers.		It is also a good technic to display very coloured layers.

			==Raster==

			Here I will refer to the traditional raster, where the colour for one pen is changed once each line. The final result is usually a horizontal bar of colour that covers the whole width of the screen.

			==Split Rasters==

			Split rasters are made by changing the colour for one pen more than once on each line. The final result is usually more than one horizontal bar of colour side by side covering the whole width of the screen.

			==Raster scroll==

			This is a form of split raster, but where the position of the first raster is offset each frame. The effect is that the entire split raster moves in the horizontal. If you then move the bars accross the screen then you can make the bars scroll. Ultimately, this can be used to form letters and a horizontal scrolling message.

			==Diagonal rasters==

			This is a form of traditional raster, but instead of timing to ensure that colours are always changed at the same time on each successive line, the timing is altered so that the colours occur at successively earlier positions on succeeding lines. The effect can be done by ensuring each line does not take 64 cycles, but instead 63 or less cycles depending on the effect wanted.


	==Exemples of Raster effect in Games==		==Exemples of Raster effect in Games==

MacDeath at 13:13, 14 October 2009

2009-10-14T13:13:41Z

← Older revision		Revision as of 13:13, 14 October 2009
Line 7:		Line 7:

	But changing the colours can be used to have different areas of the screen in different colours, e.g. for a status panel and a game area.		But changing the colours can be used to have different areas of the screen in different colours, e.g. for a status panel and a game area.

			It is also a good technic to display very coloured layers.

			==Exemples of Raster effect in Games==
			*Some GX4000 games are CPC games which include Rasters effect to add colours.
			**Crazy Car 2 : extra colours layer in the sky.
			**Fire and Forget 2 : Idem.
			**Switchblade : also a good Red layer.

			*[[Striker In The Crypts Of Trogan]] : one of the rare games in Mode 1 with "massive" use of in-game rasters (not only in the [[HUD]] actually).
			This games looks a lot like Switchblade indeed...It may be a mod of the Switchblade engine.
			Yet there is a pseudo Colour attribute clash : when monster pass from one raster to another, they change colour.

			==Exemples of Raster Effect in Demo==

	==Links==		==Links==

Arnoldemu at 09:02, 14 October 2009

2009-10-14T09:02:45Z

← Older revision		Revision as of 09:02, 14 October 2009
Line 1:		Line 1:
	~~When programming, the raster~~ is ~~often referred~~ to as the act of modifying the ~~setting~~ of ~~inks between 2 scanlines, in interrupt mode~~.		"Raster" is a demo term which refers to the act of modifying the colours while the picture is being drawn by the display (TV or monitor). This is done to display more than the usual [[Video modes]] number of colours.

	~~This is a way to~~ display ~~more than~~ the ~~usual~~ [[~~Video modes~~]] ~~number~~ of ~~colours~~.		The display draws one line every 64microseconds, with the whole image drawn at a frequency of 50Hz.
			The [[CPU]] ([[Z80]]) runs at about 4 MHz. Most instructions are multiples of a microsecond and this makes timing for making rasters easy.

	The ~~time between the display of 2 Scanlines~~ by the ~~CRTC allow the CPU to order the Gate array to modify the setting~~ of ~~inks~~.		The traditional raster is made by changing the colour for one pen once each line creating a horizontal bar of colour.

	~~The screen is updated with a frequency of 50Hz...The [[CPU]] ([[Z80]]) runs at about 4 MHz.~~		But changing the colours can be used to have different areas of the screen in different colours, e.g. for a status panel and a game area.

	~~So It has enough cycles between 2 scanlines to order this.~~

	~~You~~ can ~~also use Split raster~~ to ~~"actually" display 2~~ different ~~screens~~, ~~sometimes with different Video Modes~~. ~~This also allows~~ a ~~Graphic heavy [[HUD]] with no interference with [[Scrolling]]~~.

	==Links==		==Links==

CPCLER: // Well spelling, no native but :-)

2009-10-14T08:27:46Z

// Well spelling, no native but :-)

← Older revision		Revision as of 08:27, 14 October 2009
Line 1:		Line 1:
	~~In programation~~, the raster is often referred as the act ~~to modify~~ the setting of inks between 2 scanlines, in interrupt mode.		When programming, the raster is often referred to as the act of modifying the setting of inks between 2 scanlines, in interrupt mode.

	This is a way to display more than the usual [[Video modes]] number of colours.		This is a way to display more than the usual [[Video modes]] number of colours.
Line 5:		Line 5:
	The time between the display of 2 Scanlines by the CRTC allow the CPU to order the Gate array to modify the setting of inks.		The time between the display of 2 Scanlines by the CRTC allow the CPU to order the Gate array to modify the setting of inks.

	The screen ~~display at~~ 50Hz...The [[CPU]] ([[Z80]]) runs at about 4 ~~MgHz~~.		The screen is updated with a frequency of 50Hz...The [[CPU]] ([[Z80]]) runs at about 4 MHz.

	So It has enough cycles between 2 scanlines to order this.		So It has enough cycles between 2 scanlines to order this.

	You can also use Split raster to "actually" display 2 different screens, sometimes with different Video Modes. This also allows a Graphic heavy [[HUD]] with no interference with [[Scrolling]].		You can also use Split raster to "actually" display 2 different screens, sometimes with different Video Modes. This also allows a Graphic heavy [[HUD]] with no interference with [[Scrolling]].




	==Links==		==Links==


	*[http://en.wikipedia.org/wiki/Raster Wikipedia link to Raster concepts]		*[http://en.wikipedia.org/wiki/Raster Wikipedia link to Raster concepts]
Line 27:		Line 23:

	*[[Synchronising with the CRTC and display]]		*[[Synchronising with the CRTC and display]]


	*[[Programming:Simple Raster Example 1]]		*[[Programming:Simple Raster Example 1]]

MacDeath at 21:42, 13 October 2009

2009-10-13T21:42:28Z

← Older revision		Revision as of 21:42, 13 October 2009
Line 1:		Line 1:
	In programation, the raster is often referred as the act to modify the setting of inks between 2 scanlines.		In programation, the raster is often referred as the act to modify the setting of inks between 2 scanlines, in interrupt mode.

	This is a way to display more than the usual [[Video modes]] number of colours.		This is a way to display more than the usual [[Video modes]] number of colours.
Line 9:		Line 9:
	So It has enough cycles between 2 scanlines to order this.		So It has enough cycles between 2 scanlines to order this.

	You can also use Split ~~rasterto~~ "actually" display 2 different screens, ~~sometoimes~~ with different Video Modes.		You can also use Split raster to "actually" display 2 different screens, sometimes with different Video Modes. This also allows a Graphic heavy [[HUD]] with no interference with [[Scrolling]].