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		<title>[A5] Problem with alpha blending.</title>
		<link>http://www.allegro.cc/forums/view/606568</link>
		<description>Allegro.cc Forum Thread</description>
		<webMaster>matthew@allegro.cc (Matthew Leverton)</webMaster>
		<lastBuildDate>Tue, 01 Mar 2011 21:10:32 +0000</lastBuildDate>
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		<description><![CDATA[<div class="mockup v2"><p>Hi, I am using Allegro 5.0.0 (The latest release) and I am having problems with alpha blending. I used to use allegro 4.9.22 and the code I was using is below.</p><div class="source-code"><div class="toolbar"><span class="button numbers"><b>#</b></span><span class="button select">Select</span><span class="button expand">Expand</span></div><div class="inner"><span class="number"> 1</span><a href="http://www.allegro.cc/manual/al_set_blender"><span class="a">al_set_blender</span></a><span class="k2">(</span>ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span>, <span class="n">0</span>.<span class="n">3</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 2</span><a href="http://www.allegro.cc/manual/al_draw_bitmap_region"><span class="a">al_draw_bitmap_region</span></a><span class="k2">(</span>gfx.player<span class="k2">[</span>player.gfxID<span class="k2">]</span>, start_x, start_y, width, height, dest_x, dest_y, facing_flip<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 3</span><a href="http://www.allegro.cc/manual/al_set_blender"><span class="a">al_set_blender</span></a><span class="k2">(</span>ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
</div></div><p>

Can anyone help with getting this to work under the latest release as I have been trying for 3 days now and can&#39;t get it right.</p><p>Thanks in advanced.
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		</description>
		<author>no-reply@allegro.cc (Desmond Taylor)</author>
		<pubDate>Tue, 01 Mar 2011 20:24:32 +0000</pubDate>
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		<description><![CDATA[<div class="mockup v2"><p>If you look at the documentation for al_set_blender (e.g. by clicking on it inside the code you posted), you&#39;ll notice that it only takes three parameters not four.</p><p>What exact problems are you having?</p><p>Post the shortest possible compilable code sample which reproduces the problem and attach the bitmap you&#39;re trying to draw.
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		<author>no-reply@allegro.cc (Dennis)</author>
		<pubDate>Tue, 01 Mar 2011 20:30:52 +0000</pubDate>
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		<description><![CDATA[<div class="mockup v2"><div class="quote_container"><div class="title"><a href="http://www.allegro.cc/forums/thread/606568/905843#target">Dennis</a> said:</div><div class="quote"><p>If you look at the documentation for al_set_blender (e.g. by clicking on it inside the code you posted), you&#39;ll notice that it only takes three parameters not four.</p><p>What exact problems are you having?</p><p>Post the shortest possible compilable code sample which reproduces the problem and attach the bitmap you&#39;re trying to draw.</p></div></div><p>

I have looked at the documentation and I have tried messing with the values but get really bad effects.</p><p>I can&#39;t post the Bitmap as it is in a PE file, however I will post a screen shot of what I am trying to get. The screen shot is what I get when using the code in my first post.</p><p><span class="remote-thumbnail"><span class="json">{"name":"603527","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/1\/b\/1bb5944471725de4ebe0306ad22d82c0.png","w":640,"h":480,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/1\/b\/1bb5944471725de4ebe0306ad22d82c0"}</span><img src="http://www.allegro.cc//djungxnpq2nug.cloudfront.net/image/cache/1/b/1bb5944471725de4ebe0306ad22d82c0-240.jpg" alt="603527" width="240" height="180" /></span>
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		<author>no-reply@allegro.cc (Desmond Taylor)</author>
		<pubDate>Tue, 01 Mar 2011 20:47:38 +0000</pubDate>
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		<description><![CDATA[<div class="mockup v2"><div class="source-code snippet"><div class="inner"><pre><a href="http://www.allegro.cc/manual/al_set_blender"><span class="a">al_set_blender</span></a><span class="k2">(</span>ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span>, <span class="n">0</span>.<span class="n">3</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<a href="http://www.allegro.cc/manual/al_draw_bitmap_region"><span class="a">al_draw_bitmap_region</span></a><span class="k2">(</span>gfx.player<span class="k2">[</span>player.gfxID<span class="k2">]</span>, start_x, start_y, width, height, dest_x, dest_y, facing_flip<span class="k2">)</span><span class="k2">;</span>
</pre></div></div><p>

Becomes:
</p><div class="source-code snippet"><div class="inner"><pre><a href="http://www.allegro.cc/manual/al_set_blender"><span class="a">al_set_blender</span></a><span class="k2">(</span>ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA<span class="k2">)</span><span class="k2">;</span>
<a href="http://www.allegro.cc/manual/al_draw_tinted_bitmap_region"><span class="a">al_draw_tinted_bitmap_region</span></a><span class="k2">(</span>gfx.player<span class="k2">[</span>player.gfxID<span class="k2">]</span>, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span>, <span class="n">0</span>.<span class="n">3</span><span class="k2">)</span>, start_x, start_y, width, height, dest_x, dest_y, facing_flip<span class="k2">)</span><span class="k2">;</span>
</pre></div></div><p>

Or, if using the default blender:
</p><div class="source-code snippet"><div class="inner"><pre><a href="http://www.allegro.cc/manual/al_draw_tinted_bitmap_region"><span class="a">al_draw_tinted_bitmap_region</span></a><span class="k2">(</span>gfx.player<span class="k2">[</span>player.gfxID<span class="k2">]</span>, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span> <span class="k3">*</span> <span class="n">0</span>.<span class="n">3</span>, <span class="n">1</span> <span class="k3">*</span> <span class="n">0</span>.<span class="n">3</span>, <span class="n">1</span> <span class="k3">*</span> <span class="n">0</span>.<span class="n">3</span>, <span class="n">0</span>.<span class="n">3</span><span class="k2">)</span>, start_x, start_y, width, height, dest_x, dest_y, facing_flip<span class="k2">)</span><span class="k2">;</span>
</pre></div></div><p>
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		</description>
		<author>no-reply@allegro.cc (Matthew Leverton)</author>
		<pubDate>Tue, 01 Mar 2011 21:05:30 +0000</pubDate>
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		<description><![CDATA[<div class="mockup v2"><p>Thank you so much. I understand how this works now <img src="http://www.allegro.cc/forums/smileys/smiley.gif" alt=":)" /></p><p>I used your code here.
</p><div class="source-code"><div class="toolbar"><span class="button numbers"><b>#</b></span><span class="button select">Select</span><span class="button expand">Expand</span></div><div class="inner"><span class="number"> 1</span><a href="http://www.allegro.cc/manual/al_set_blender"><span class="a">al_set_blender</span></a><span class="k2">(</span>ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 2</span><a href="http://www.allegro.cc/manual/al_draw_tinted_bitmap_region"><span class="a">al_draw_tinted_bitmap_region</span></a><span class="k2">(</span>gfx.player<span class="k2">[</span>player.gfxID<span class="k2">]</span>, <a href="http://www.allegro.cc/manual/al_map_rgba_f"><span class="a">al_map_rgba_f</span></a><span class="k2">(</span><span class="n">1</span>, <span class="n">1</span>, <span class="n">1</span>, <span class="n">0</span>.<span class="n">3</span><span class="k2">)</span>, start_x, start_y, width, height, dest_x, dest_y, facing_flip<span class="k2">)</span><span class="k2">;</span>
</div></div><p>

And it worked perfectly <img src="http://www.allegro.cc/forums/smileys/smiley.gif" alt=":)" /></p><p>Thanks again Guys <img src="http://www.allegro.cc/forums/smileys/smiley.gif" alt=":)" />
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		<author>no-reply@allegro.cc (Desmond Taylor)</author>
		<pubDate>Tue, 01 Mar 2011 21:10:32 +0000</pubDate>
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