Media Software Design

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Media Software Design

DIG 3134Fall 2012

Lecture 15: Graphics

J. Michael MoshellUniversity of Central Florida

Original image* by Moshell et al .

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PHP GraphicsThe Coordinate System (for our example)

x 800

y

600

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PHP GraphicsMotivation: the RSL Pickup Graph


PHP GraphicsThe Coordinate System (for our example)

x 0 800y 0 600

600 0 yup = 600-y (so y=600 – yup)


PHP Graphics: The GD Libraryhttp://php.net/manual/en/ref.image.phpBasic example:$Imagewidth=800;$Imageheight=600;$image=imagecreate($Imagewidth, $Imageheight);$colorWhite=imagecolorallocate($image, 255, 255, 255);$colorGreen=imagecolorallocate($image, 0, 200, 0);

// x1 y1 x2 y2imageline($image, 300, 200, 300,550, $coloGreen); imagepng($image,'graphout.png');imagedestroy($image);print '<img src="graphout.png?lastmod=1">';




Do this to forcethe browser not to cache

the png file.If it is cached, you

won't see changes ... frustrating.




Do this to forcethe browser not to cache

the png file.If it is cached, you

won't see changes ... frustrating.NOTE: This sometimes

sorta works

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markbeam.com

Project 4: Cowpies

Examine the cowpie1 prototype.

BehaviorCode

Examine the Requirements for Project 4

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Project 4: Cowpies

Requirements BEGIN with a database task:** remember previous moves and replay them.

So we will BEGIN (next week) with a tutorial database examplecalled "address book" to build up your database skills, andalso give you some code to steal / merge with cowpie1.php.

Let's look at one more graphical issue.

Can we write our .png DIRECTLY to browser?


PHP Graphics: The GD LibraryCan we write the

image DIRECTLY tothe browser, instead ofinto a file? Docs saywe can, so we try it.



// x1 y1 x2 y2imageline($image, 300, 200, 300,550, $coloGreen); imagepng($image);imagedestroy($image);print '<img src="graphout.png?lastmod=1">';

Can we write theimage DIRECTLY tothe browser, instead ofinto a file? Docs saywe can, so we try it.

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GD direct to screen: ??

What's this?Any ideas?

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What's this?Any ideas?

View Source

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Once you've announced to the browser that HTML iscoming, it expects HTML.

So what if we tried a different header?

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So what if we tried a different header?PHP has a header function. We modify cowpie1.php:

function htmlheader(){

print "<html><body><form method='post'>";}//main program$angle=$_POST['angle']; $velocity=$_POST['velocity'];if (!$angle)

htmlheader(); //need HTML first time for formelse

header('Content-type: image/png');

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Result: yes, it "works" ... but now it's not an HTML formany more, so there are no inputs (controls). It's not interactive.

So ... we're better off embedding png in html.

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FOR THURSDAY:The usual shoot-out model:GET your Group's BEST GAME ready to play!

If you need help with Project 3, come SEE ME.

Media Software Design

Documents

gd libraryhttp

gd direct

gd librarycan

forcethe browser

phpbasic example

tothe browser

x1 y1 x2 y2imageline

cologreen imagepng