{"id":656,"date":"2013-11-23T17:41:16","date_gmt":"2013-11-23T16:41:16","guid":{"rendered":"http:\/\/labalec.fr\/erwan\/?p=656"},"modified":"2013-11-23T18:02:08","modified_gmt":"2013-11-23T17:02:08","slug":"vb-net-and-xna-article-12-pixel-collision-on-rotated-shapes","status":"publish","type":"post","link":"https:\/\/labalec.fr\/erwan\/?p=656","title":{"rendered":"VB.Net and XNA : Article 12 – Pixel collision on rotated shapes"},"content":{"rendered":"

We have seen in previous article 8<\/a> how to perform pixel collision.
\nAltough it worked perfectly, it only worked on non rotated shapes.<\/p>\n

But in some cases, your shape will rotate (like a car in a racing game – see article \u00ab\u00a0A racing car game\u00a0\u00bb<\/a>).<\/p>\n

To perform pixel collision for a rotated shape, here below the steps :<\/p>\n

-you first need to draw a rotated rectangle around your shape
\n-you then need to draw a bounding rectanle around that rotated rectangle (also called AABB : Axis Aligned Bounding Box)
\n-finally you can check whether 2 AABB intersects, and if so, if in the intersected region, we have 2 non transparent pixels (colliding) or not<\/p>\n

The source code : XNA_DEMO_18<\/a>
\nNote : the project contains a class named primitives2d which is used only to draw lines\/rectangles around my objects.<\/p>\n

Lets illustrate this with some screenshots.<\/p>\n

Lets rotate our rectangle along with my rocket<\/strong>
\n\"pixel2\"<\/a><\/p>\n

Lets define our bounding box<\/strong>
\n\"pixel3\"<\/a><\/p>\n

Despite bounding boxes intersecting, we dont detect collision yet<\/strong>
\n\"pixel4\"<\/a><\/p>\n

Here we go ! In the intersection region, there are 2 non transparent pixels<\/strong>
\n\"pixel5\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

We have seen in previous article 8 how to perform pixel collision. Altough it worked perfectly, it only worked on non rotated shapes. But in some cases, your shape will rotate (like a car in a racing game – see article \u00ab\u00a0A racing car game\u00a0\u00bb). To perform pixel collision for a rotated shape, here below […]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34,35],"tags":[],"class_list":["post-656","post","type-post","status-publish","format-standard","hentry","category-dotnet","category-xna","category-34-id","category-35-id","post-seq-1","post-parity-odd","meta-position-corners","fix"],"_links":{"self":[{"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/posts\/656","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=656"}],"version-history":[{"count":9,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/posts\/656\/revisions"}],"predecessor-version":[{"id":671,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=\/wp\/v2\/posts\/656\/revisions\/671"}],"wp:attachment":[{"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/labalec.fr\/erwan\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}