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		<title>Restarting display to change multisampling has effect on vsync</title>
		<link>http://www.allegro.cc/forums/view/611431</link>
		<description>Allegro.cc Forum Thread</description>
		<webMaster>matthew@allegro.cc (Matthew Leverton)</webMaster>
		<lastBuildDate>Tue, 13 Nov 2012 07:43:42 +0000</lastBuildDate>
	</channel>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Hello,<br />I have the option to change multisampling configuration in the game.</p><p>I didn&#39;t want to be like those &quot;lame&quot; games that said: &quot;You have to restart the game if you want to change this option&quot;</p><p>So when the user changes the multisampling option, I destroy all bitmaps, fonts and display and create it again:</p><p>Shut down:
</p><div class="source-code snippet"><div class="inner"><pre>  <a href="http://www.allegro.cc/manual/al_destroy_font"><span class="a">al_destroy_font</span></a><span class="k2">(</span>this-&gt;font<span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_destroy_font"><span class="a">al_destroy_font</span></a><span class="k2">(</span>this-&gt;itemCountFont<span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_shutdown_font_addon"><span class="a">al_shutdown_font_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_shutdown_ttf_addon"><span class="a">al_shutdown_ttf_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_shutdown_primitives_addon"><span class="a">al_shutdown_primitives_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_shutdown_image_addon"><span class="a">al_shutdown_image_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
  <a href="http://www.allegro.cc/manual/al_destroy_display"><span class="a">al_destroy_display</span></a><span class="k2">(</span>this-&gt;display<span class="k2">)</span><span class="k2">;</span>
</pre></div></div><p>

and create it again:</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>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_init"><span class="a">al_init</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number">  2</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to initialize allegro!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number">  3</span>  <a href="http://www.allegro.cc/manual/al_set_new_display_flags"><span class="a">al_set_new_display_flags</span></a><span class="k2">(</span>ALLEGRO_RESIZABLE<span class="k2">)</span><span class="k2">;</span>
<span class="number">  4</span>  <a href="http://www.allegro.cc/manual/al_set_new_display_option"><span class="a">al_set_new_display_option</span></a><span class="k2">(</span>ALLEGRO_VSYNC, <span class="n">1</span>, ALLEGRO_SUGGEST<span class="k2">)</span><span class="k2">;</span>
<span class="number">  5</span>  <span class="k1">if</span> <span class="k2">(</span>global-&gt;graphicsSettings-&gt;getMultisamplingLevel<span class="k2">(</span><span class="k2">)</span> <span class="k3">!</span><span class="k3">=</span> <span class="n">0</span><span class="k2">)</span>
<span class="number">  6</span>  <span class="k2">{</span>
<span class="number">  7</span>    <a href="http://www.allegro.cc/manual/al_set_new_bitmap_flags"><span class="a">al_set_new_bitmap_flags</span></a><span class="k2">(</span>ALLEGRO_MIN_LINEAR <span class="k3">|</span> ALLEGRO_MAG_LINEAR <span class="k3">|</span> ALLEGRO_VIDEO_BITMAP<span class="k2">)</span><span class="k2">;</span>
<span class="number">  8</span>    <a href="http://www.allegro.cc/manual/al_set_new_display_option"><span class="a">al_set_new_display_option</span></a><span class="k2">(</span>ALLEGRO_SAMPLE_BUFFERS, <span class="n">1</span>, ALLEGRO_SUGGEST<span class="k2">)</span><span class="k2">;</span>
<span class="number">  9</span>    <a href="http://www.allegro.cc/manual/al_set_new_display_option"><span class="a">al_set_new_display_option</span></a><span class="k2">(</span>ALLEGRO_SAMPLES, global-&gt;graphicsSettings-&gt;getMultisamplingLevel<span class="k2">(</span><span class="k2">)</span>, ALLEGRO_SUGGEST<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 10</span>  <span class="k2">}</span>
<span class="number"> 11</span>  <span class="k1">else</span>
<span class="number"> 12</span>  <span class="k2">{</span>
<span class="number"> 13</span>    <a href="http://www.allegro.cc/manual/al_set_new_bitmap_flags"><span class="a">al_set_new_bitmap_flags</span></a><span class="k2">(</span>ALLEGRO_VIDEO_BITMAP<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 14</span>    <a href="http://www.allegro.cc/manual/al_set_new_display_option"><span class="a">al_set_new_display_option</span></a><span class="k2">(</span>ALLEGRO_SAMPLE_BUFFERS, <span class="n">0</span>, ALLEGRO_SUGGEST<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 15</span>    <a href="http://www.allegro.cc/manual/al_set_new_display_option"><span class="a">al_set_new_display_option</span></a><span class="k2">(</span>ALLEGRO_SAMPLES, <span class="n">0</span>, ALLEGRO_SUGGEST<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 16</span>  <span class="k2">}</span>
<span class="number"> 17</span>
<span class="number"> 18</span>  <a href="http://www.allegro.cc/manual/al_set_new_window_position"><span class="a">al_set_new_window_position</span></a><span class="k2">(</span>global-&gt;properties.get<span class="k3">&lt;</span>int&gt;<span class="k2">(</span><span class="s">"screen.x"</span>, <span class="n">100</span><span class="k2">)</span>,
<span class="number"> 19</span>                             global-&gt;properties.get<span class="k3">&lt;</span>int&gt;<span class="k2">(</span><span class="s">"screen.y"</span>, <span class="n">100</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 20</span>
<span class="number"> 21</span>  this-&gt;display <span class="k3">=</span> <a href="http://www.allegro.cc/manual/al_create_display"><span class="a">al_create_display</span></a><span class="k2">(</span>global-&gt;properties.get<span class="k3">&lt;</span>int&gt;<span class="k2">(</span><span class="s">"screen.width"</span>, <span class="n">800</span><span class="k2">)</span>,
<span class="number"> 22</span>                                    global-&gt;properties.get<span class="k3">&lt;</span>int&gt;<span class="k2">(</span><span class="s">"screen.height"</span>, <span class="n">600</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 23</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span>this-&gt;display<span class="k2">)</span>
<span class="number"> 24</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to create display!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 25</span>
<span class="number"> 26</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_init_image_addon"><span class="a">al_init_image_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 27</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Failed to initialize al_init_image_addon!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 28</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_install_keyboard"><span class="a">al_install_keyboard</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 29</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to initialize the keyboard!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 30</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_install_mouse"><span class="a">al_install_mouse</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 31</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to initialize the mouse!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 32</span>  <a href="http://www.allegro.cc/manual/al_init_font_addon"><span class="a">al_init_font_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 33</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_init_ttf_addon"><span class="a">al_init_ttf_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 34</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to initialize the ttf addon!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 35</span>  this-&gt;font <span class="k3">=</span> <a href="http://www.allegro.cc/manual/al_load_ttf_font"><span class="a">al_load_ttf_font</span></a><span class="k2">(</span><span class="k2">(</span>global-&gt;resourcePath <span class="k3">/</span> <span class="s">"cm_ss_2012.ttf"</span><span class="k2">)</span>.string<span class="k2">(</span><span class="k2">)</span>.c_str<span class="k2">(</span><span class="k2">)</span>, <span class="n">22</span>, ALLEGRO_TTF_RENDER_BORDER<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 36</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span>Display::font<span class="k2">)</span>
<span class="number"> 37</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Could not load 'cm_ss_2012.ttf'."</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 38</span>  al_set_ttf_border<span class="k2">(</span>this-&gt;font, <span class="n">1</span>, <a href="http://www.allegro.cc/manual/al_map_rgb"><span class="a">al_map_rgb</span></a><span class="k2">(</span><span class="n">0</span>, <span class="n">0</span>, <span class="n">100</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 39</span>  Display::itemCountFont <span class="k3">=</span> <a href="http://www.allegro.cc/manual/al_load_ttf_font"><span class="a">al_load_ttf_font</span></a><span class="k2">(</span><span class="k2">(</span>global-&gt;resourcePath <span class="k3">/</span> <span class="s">"cm_ss_2012.ttf"</span><span class="k2">)</span>.string<span class="k2">(</span><span class="k2">)</span>.c_str<span class="k2">(</span><span class="k2">)</span>, <span class="n">16</span>, ALLEGRO_TTF_RENDER_BORDER<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 40</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span>Display::itemCountFont<span class="k2">)</span>
<span class="number"> 41</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Could not load 'cm_ss_2012.ttf'."</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 42</span>  al_set_ttf_border_color<span class="k2">(</span>this-&gt;itemCountFont, <a href="http://www.allegro.cc/manual/al_map_rgb"><span class="a">al_map_rgb</span></a><span class="k2">(</span><span class="n">60</span>, <span class="n">60</span>, <span class="n">60</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 43</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_init_primitives_addon"><span class="a">al_init_primitives_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 44</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"failed to load primitives addon!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 45</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_install_audio"><span class="a">al_install_audio</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 46</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Failed to install audio!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 47</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_init_acodec_addon"><span class="a">al_init_acodec_addon</span></a><span class="k2">(</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 48</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Failed to initialize audio codecs!"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 49</span>  <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span><a href="http://www.allegro.cc/manual/al_reserve_samples"><span class="a">al_reserve_samples</span></a><span class="k2">(</span><span class="n">50</span><span class="k2">)</span><span class="k2">)</span>
<span class="number"> 50</span>    <span class="k1">throw</span> std::runtime_error<span class="k2">(</span><span class="s">"Failed to reserve samples!"</span><span class="k2">)</span><span class="k2">;</span>
</div></div><p>

(I hope that calling something even when it wasn&#39;t shut down, like al_init, or al_install_audio isn&#39;t problem)</p><p>Anyway, when I change the multisampling option and restart graphics this way, everything works, just the VSYNC works on 1/2 of normal speed (30 fps instead of 60)</p><p>Any idea why is this happening?</p><p>PS. I&#39;m making sure that the reason isn&#39;t performance, the game spends 10% of available time in the game loop rest in waiting for vsync.
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (kovarex)</author>
		<pubDate>Tue, 13 Nov 2012 07:43:42 +0000</pubDate>
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