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elerea-examples 1.0.0 → 1.0.1

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@@ -1,5 +1,5 @@ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title></title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><meta name="generator" content="pandoc" /><link rel="stylesheet" href="hscolour.css" type="text/css" media="all" />-</head><body><h1 id="elerea-breakout-example">Elerea Breakout example</h1><p>Breakout is one of the simplest test applications that brings up some problems with non-trivial solutions. In particular, there is a circular dependency between the position and the velocity of the ball. The position is the integral of the velocity, while velocity can have instantaneous changes due to collisions, which is a function of the position of the ball and the current state of the field. The field is dynamic, and it also forms a mutual dependency loop with the ball position. On top of these, part of the field (at least if we regard the paddle as part of it) depends on user input, and its effects start propagating in the game state as soon as the ball reaches the level of the paddle.</p><p>Elerea lets us express all these circular dependencies in a natural way, by simply referring to the respective signals by their names. User input is also seen as a signal from inside the reactive part, while the imperative framework is given a sink fuction to update it as needed. Type safety is ensured all the way.</p><img src="Breakout.png" alt="Elerea Breakout in action" /><p>You can also have the program output the signal structure in <a href="http://www.graphviz.org/">Graphviz</a> dot format with the <code>--dump-dot</code> switch after the game is over. For instance, if Graphviz is installed, you can get an SVG rendition of the graph using the following command:</p><p><code>elerea-breakout --dump-dot | dot -Tsvg -o breakout.svg</code></p><p>Below follows the full source of the example.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE RecursiveDo #-}</span>+</head><body><div id="elerea-breakout-example"><h1>Elerea Breakout example</h1><p>Breakout is one of the simplest test applications that brings up some problems with non-trivial solutions. In particular, there is a circular dependency between the position and the velocity of the ball. The position is the integral of the velocity, while velocity can have instantaneous changes due to collisions, which is a function of the position of the ball and the current state of the field. The field is dynamic, and it also forms a mutual dependency loop with the ball position. On top of these, part of the field (at least if we regard the paddle as part of it) depends on user input, and its effects start propagating in the game state as soon as the ball reaches the level of the paddle.</p><p>Elerea lets us express all these circular dependencies in a natural way, by simply referring to the respective signals by their names. User input is also seen as a signal from inside the reactive part, while the imperative framework is given a sink fuction to update it as needed. Type safety is ensured all the way.</p><img src="Breakout.png" alt="Elerea Breakout in action" /><p>You can also have the program output the signal structure in <a href="http://www.graphviz.org/">Graphviz</a> dot format with the <code>--dump-dot</code> switch after the game is over. For instance, if Graphviz is installed, you can get an SVG rendition of the graph using the following command:</p><p><code>elerea-breakout --dump-dot | dot -Tsvg -o breakout.svg</code></p><p>Below follows the full source of the example.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE RecursiveDo #-}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Main</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> @@ -19,7 +19,7 @@ </pre> <pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Vector</span>-</pre><h2 id="global-constants">Global constants</h2><p>The dimensions of the ball, which behaves as a rectangle in collision detection, but is drawn as an ellipse.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>ballW</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.04</span>+</pre><div id="global-constants"><h2>Global constants</h2><p>The dimensions of the ball, which behaves as a rectangle in collision detection, but is drawn as an ellipse.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>ballW</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.04</span> <span class='hs-varop'>&gt;</span> <span class='hs-varid'>ballH</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.04</span> </pre><p>The initial position and velocity of the ball.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>ballPos0</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-comment'>-</span><span class='hs-num'>0.4</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span> <span class='hs-varid'>ballVel0</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-comment'>-</span><span class='hs-num'>0.4</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-num'>0.35</span><span class='hs-layout'>)</span>@@ -30,14 +30,14 @@ <span class='hs-varop'>&gt;</span> <span class='hs-varid'>fieldH</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.5</span> </pre><p>The dimensions of each brick.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>brickW</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.05</span> <span class='hs-varop'>&gt;</span> <span class='hs-varid'>brickH</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.03</span>-</pre><p>The data structure describing the state of each brick. A brick can either be alive or dying. Dying bricks also keep track of their fadeout level.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>BrickState</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Live</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Dying</span> <span class='hs-varop'>!</span><span class='hs-conid'>Double</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span><span class='hs-conid'>Show</span><span class='hs-layout'>)</span>+</pre><p>The data structure describing the state of each brick. A brick can either be alive or dying. Dying bricks also keep track of their fadeout level.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>BrickState</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Live</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Dying</span> <span class='hs-varop'>!</span><span class='hs-conid'>GLfloat</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span><span class='hs-conid'>Show</span><span class='hs-layout'>)</span> </pre><p>The starting positions of the bricks.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>brickPos0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>distributeBricks</span> <span class='hs-layout'>(</span><span class='hs-comment'>-</span><span class='hs-num'>0.7</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-comment'>-</span><span class='hs-num'>0.1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-num'>0.7</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-num'>0.4</span><span class='hs-layout'>)</span> <span class='hs-num'>18</span> <span class='hs-num'>10</span> <span class='hs-varop'>&gt;</span>     <span class='hs-keyword'>where</span> <span class='hs-varid'>distributeBricks</span> <span class='hs-varid'>xmin</span> <span class='hs-varid'>ymin</span> <span class='hs-varid'>xmax</span> <span class='hs-varid'>ymax</span> <span class='hs-varid'>xn</span> <span class='hs-varid'>yn</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>xmin</span><span class='hs-varop'>+</span><span class='hs-varid'>xstep</span><span class='hs-varop'>*</span><span class='hs-varid'>x</span><span class='hs-layout'>,</span><span class='hs-varid'>ymin</span><span class='hs-varop'>+</span><span class='hs-varid'>ystep</span><span class='hs-varop'>*</span><span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varop'>&gt;</span>                                                         <span class='hs-varid'>x</span> <span class='hs-keyglyph'>&larr;</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-varid'>xn</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>&larr;</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-varid'>yn</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>&gt;</span>               <span class='hs-keyword'>where</span> <span class='hs-varid'>xstep</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>xmax</span><span class='hs-comment'>-</span><span class='hs-varid'>xmin</span><span class='hs-comment'>-</span><span class='hs-varid'>xn</span><span class='hs-varop'>*</span><span class='hs-varid'>brickW</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-layout'>(</span><span class='hs-varid'>xn</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span><span class='hs-varop'>+</span><span class='hs-varid'>brickW</span> <span class='hs-varop'>&gt;</span>                     <span class='hs-varid'>ystep</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>ymax</span><span class='hs-comment'>-</span><span class='hs-varid'>ymin</span><span class='hs-comment'>-</span><span class='hs-varid'>yn</span><span class='hs-varop'>*</span><span class='hs-varid'>brickH</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-layout'>(</span><span class='hs-varid'>yn</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span><span class='hs-varop'>+</span><span class='hs-varid'>brickH</span> </pre><p>The rate at which a brick fades out. The reciprocal of this value gives the fadeout time in seconds.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>brickFade</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0.5</span>-</pre><h2 id="game-logic">Game logic</h2><p>The entry point performs some lightweight initialisation, and defines the two user-driven signals: window size and mouse position. The <code>external</code> function creates the signal and the corresponding sink at the same time.</p><p>When all is done <code>driveNetwork</code> is invoked. It is not a library function, but part of the tiny <code>Utils</code> module .</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>main</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>+</pre></div><div id="game-logic"><h2>Game logic</h2><p>The entry point performs some lightweight initialisation, and defines the two user-driven signals: window size and mouse position. The <code>external</code> function creates the signal and the corresponding sink at the same time.</p><p>When all is done <code>driveNetwork</code> is invoked. It is not a library function, but part of the tiny <code>Utils</code> module .</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>main</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varop'>&gt;</span>   <span class='hs-comment'>-- Creating a window without a depth buffer</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>initialize</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>openWindow</span> <span class='hs-layout'>(</span><span class='hs-conid'>Size</span> <span class='hs-num'>640</span> <span class='hs-num'>480</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>DisplayRGBBits</span> <span class='hs-num'>8</span> <span class='hs-num'>8</span> <span class='hs-num'>8</span><span class='hs-layout'>,</span> <span class='hs-conid'>DisplayAlphaBits</span> <span class='hs-num'>8</span><span class='hs-keyglyph'>]</span> <span class='hs-conid'>Window</span>@@ -148,7 +148,7 @@ <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>flush</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>swapBuffers</span>-</pre><h2 id="backend">Backend</h2><p>The <code>readInput</code> function has two responsibilities: it provides input for the <code>mousePosition</code> peripheral signal through its associated sink, and also feeds the time difference between two states into the system, deciding when to exit altogether (by returning <code>Nothing</code> instead of the current <code>dt</code> value wrapped in <code>Just</code>).</p><p>The <code>threadDelay</code> call at the beginning is just a trick to give the scheduler a breath. It will cause a wait equal to a scheduler tick, which is 20ms by default. The program can run perfectly without it, but it eats up all the free CPU to produce an unnecessarily high frame rate.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>readInput</span> <span class='hs-varid'>mousePos</span> <span class='hs-varid'>closed</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>+</pre></div><div id="backend"><h2>Backend</h2><p>The <code>readInput</code> function has two responsibilities: it provides input for the <code>mousePosition</code> peripheral signal through its associated sink, and also feeds the time difference between two states into the system, deciding when to exit altogether (by returning <code>Nothing</code> instead of the current <code>dt</code> value wrapped in <code>Just</code>).</p><p>The <code>threadDelay</code> call at the beginning is just a trick to give the scheduler a breath. It will cause a wait equal to a scheduler tick, which is 20ms by default. The program can run perfectly without it, but it eats up all the free CPU to produce an unnecessarily high frame rate.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>readInput</span> <span class='hs-varid'>mousePos</span> <span class='hs-varid'>closed</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>threadDelay</span> <span class='hs-num'>0</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>t</span> <span class='hs-keyglyph'>&larr;</span> <span class='hs-varid'>get</span> <span class='hs-conid'>GLFW</span><span class='hs-varop'>.</span><span class='hs-varid'>time</span> <span class='hs-varop'>&gt;</span>   <span class='hs-conid'>GLFW</span><span class='hs-varop'>.</span><span class='hs-varid'>time</span> <span class='hs-varop'>$=</span> <span class='hs-num'>0</span>@@ -172,7 +172,7 @@ <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>scale</span> <span class='hs-num'>1</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>w</span><span class='hs-varop'>/</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>h</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-num'>1</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GLfloat</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>matrixMode</span> <span class='hs-varop'>$=</span> <span class='hs-conid'>Modelview</span> <span class='hs-num'>0</span>-</pre><h1 id="utils-module">Utils module</h1><p>This module contains some functions that might make it into the core library eventually.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span> <span class='hs-keyword'>where</span>+</pre></div></div><div id="utils-module"><h1>Utils module</h1><p>This module contains some functions that might make it into the core library eventually.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span>@@ -187,14 +187,15 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span> </pre><p>A scalar integral function for <code>Fractional</code> instances.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>integral</span> <span class='hs-varid'>v0</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transfer</span> <span class='hs-varid'>v0</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>dt</span> <span class='hs-varid'>v</span> <span class='hs-varid'>v0</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v0</span><span class='hs-varop'>+</span><span class='hs-varid'>v</span><span class='hs-varop'>*</span><span class='hs-varid'>realToFrac</span> <span class='hs-varid'>dt</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span> </pre><p>An integral function for two-dimensional vectors defined in the <code>Vector</code> module.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>integralVec</span> <span class='hs-varid'>v0</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transfer</span> <span class='hs-varid'>v0</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>dt</span> <span class='hs-varid'>v</span> <span class='hs-varid'>v0</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v0</span><span class='hs-varop'>^+^</span><span class='hs-layout'>(</span><span class='hs-varid'>v</span><span class='hs-varop'>^*.</span><span class='hs-varid'>realToFrac</span> <span class='hs-varid'>dt</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>-</pre><h1 id="vector-module">Vector module</h1><p>This module contains a class for two-dimensional vectors, a strict datatype to instantiate it, and another instance for signals of the same type.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-}</span>+</pre></div><div id="vector-module"><h1>Vector module</h1><p>This module contains a class for two-dimensional vectors, a strict datatype to instantiate it, and another instance for signals of the same type. We use CFloat as the coordinate type, because GLfloat is its synonym.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Vector</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>FRP</span><span class='hs-varop'>.</span><span class='hs-conid'>Elerea</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>C</span><span class='hs-varop'>.</span><span class='hs-conid'>Types</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>Vec</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>{</span> <span class='hs-varid'>getX</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Float</span><span class='hs-layout'>,</span> <span class='hs-varid'>getY</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Float</span> <span class='hs-layout'>}</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>Vec</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>{</span> <span class='hs-varid'>getX</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>CFloat</span><span class='hs-layout'>,</span> <span class='hs-varid'>getY</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>CFloat</span> <span class='hs-layout'>}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>infixl</span> <span class='hs-num'>7</span> <span class='hs-varop'>^*.</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>infixl</span> <span class='hs-num'>7</span> <span class='hs-varop'>.*^</span>@@ -212,7 +213,7 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>dot</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>c</span> <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>cross</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>c</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-conid'>Vec</span> <span class='hs-conid'>Float</span> <span class='hs-keyword'>where</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-conid'>Vec</span> <span class='hs-conid'>CFloat</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>^+^</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span><span class='hs-varop'>+</span><span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y1</span><span class='hs-varop'>+</span><span class='hs-varid'>y2</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>^-^</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span><span class='hs-comment'>-</span><span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y1</span><span class='hs-comment'>-</span><span class='hs-varid'>y2</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-varop'>^*.</span> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-varop'>*</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-varop'>*</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span>@@ -221,7 +222,7 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>`dot`</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x1</span><span class='hs-varop'>*</span><span class='hs-varid'>y1</span><span class='hs-varop'>+</span><span class='hs-varid'>x2</span><span class='hs-varop'>*</span><span class='hs-varid'>y2</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>`cross`</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x1</span><span class='hs-varop'>*</span><span class='hs-varid'>y2</span><span class='hs-comment'>-</span><span class='hs-varid'>x2</span><span class='hs-varop'>*</span><span class='hs-varid'>y1</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Vec</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Float</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Vec</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>CFloat</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^+^</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^+^</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^-^</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^-^</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^*.</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^*.</span><span class='hs-layout'>)</span>@@ -230,4 +231,4 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>dot</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-varid'>dot</span> <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>cross</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-varid'>cross</span> </pre>-</body></html>+</div></body></html>
doc/Chase.html view
@@ -1,5 +1,5 @@ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title></title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><meta name="generator" content="pandoc" /><link rel="stylesheet" href="hscolour.css" type="text/css" media="all" />-</head><body><h1 id="elerea-chase-example">Elerea Chase example</h1><p>This is a minimal example to show how to define signals that can be mutually recursive and can optionally depend on user input too. The grey square accelerates towards the red square at a rate proportional to their relative position, and it can be given a momentary impulse with the left mouse button.</p><p>For a slightly more complex example check out <code>Breakout.lhs</code>.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE RecursiveDo #-}</span>+</head><body><div id="elerea-chase-example"><h1>Elerea Chase example</h1><p>This is a minimal example to show how to define signals that can be mutually recursive and can optionally depend on user input too. The grey square accelerates towards the red square at a rate proportional to their relative position, and it can be given a momentary impulse with the left mouse button.</p><p>For a slightly more complex example check out <code>Breakout.lhs</code>.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE RecursiveDo #-}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Main</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> @@ -83,7 +83,7 @@ <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>scale</span> <span class='hs-num'>1</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>w</span><span class='hs-varop'>/</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>h</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-num'>1</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GLfloat</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>   <span class='hs-varop'>&gt;</span>   <span class='hs-varid'>matrixMode</span> <span class='hs-varop'>$=</span> <span class='hs-conid'>Modelview</span> <span class='hs-num'>0</span>-</pre><h1 id="utils-module">Utils module</h1><p>This module contains some functions that might make it into the core library eventually.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span> <span class='hs-keyword'>where</span>+</pre></div><div id="utils-module"><h1>Utils module</h1><p>This module contains some functions that might make it into the core library eventually.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span>@@ -98,14 +98,15 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span> </pre><p>A scalar integral function for <code>Fractional</code> instances.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>integral</span> <span class='hs-varid'>v0</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transfer</span> <span class='hs-varid'>v0</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>dt</span> <span class='hs-varid'>v</span> <span class='hs-varid'>v0</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v0</span><span class='hs-varop'>+</span><span class='hs-varid'>v</span><span class='hs-varop'>*</span><span class='hs-varid'>realToFrac</span> <span class='hs-varid'>dt</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span> </pre><p>An integral function for two-dimensional vectors defined in the <code>Vector</code> module.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-varid'>integralVec</span> <span class='hs-varid'>v0</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transfer</span> <span class='hs-varid'>v0</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>dt</span> <span class='hs-varid'>v</span> <span class='hs-varid'>v0</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v0</span><span class='hs-varop'>^+^</span><span class='hs-layout'>(</span><span class='hs-varid'>v</span><span class='hs-varop'>^*.</span><span class='hs-varid'>realToFrac</span> <span class='hs-varid'>dt</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>-</pre><h1 id="vector-module">Vector module</h1><p>This module contains a class for two-dimensional vectors, a strict datatype to instantiate it, and another instance for signals of the same type.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-}</span>+</pre></div><div id="vector-module"><h1>Vector module</h1><p>This module contains a class for two-dimensional vectors, a strict datatype to instantiate it, and another instance for signals of the same type. We use CFloat as the coordinate type, because GLfloat is its synonym.</p><pre><span class='hs-varop'>&gt;</span> <span class='hs-comment'>{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Common</span><span class='hs-varop'>.</span><span class='hs-conid'>Vector</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>FRP</span><span class='hs-varop'>.</span><span class='hs-conid'>Elerea</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>C</span><span class='hs-varop'>.</span><span class='hs-conid'>Types</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>Vec</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>{</span> <span class='hs-varid'>getX</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Float</span><span class='hs-layout'>,</span> <span class='hs-varid'>getY</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Float</span> <span class='hs-layout'>}</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>data</span> <span class='hs-conid'>Vec</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>{</span> <span class='hs-varid'>getX</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>CFloat</span><span class='hs-layout'>,</span> <span class='hs-varid'>getY</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>CFloat</span> <span class='hs-layout'>}</span> <span class='hs-varop'>&gt;</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>infixl</span> <span class='hs-num'>7</span> <span class='hs-varop'>^*.</span> <span class='hs-varop'>&gt;</span> <span class='hs-keyword'>infixl</span> <span class='hs-num'>7</span> <span class='hs-varop'>.*^</span>@@ -123,7 +124,7 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>dot</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>c</span> <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>cross</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>&rarr;</span> <span class='hs-varid'>c</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-conid'>Vec</span> <span class='hs-conid'>Float</span> <span class='hs-keyword'>where</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-conid'>Vec</span> <span class='hs-conid'>CFloat</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>^+^</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span><span class='hs-varop'>+</span><span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y1</span><span class='hs-varop'>+</span><span class='hs-varid'>y2</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>^-^</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span><span class='hs-comment'>-</span><span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y1</span><span class='hs-comment'>-</span><span class='hs-varid'>y2</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-varop'>^*.</span> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>V</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-varop'>*</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-varop'>*</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span>@@ -132,7 +133,7 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>`dot`</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x1</span><span class='hs-varop'>*</span><span class='hs-varid'>y1</span><span class='hs-varop'>+</span><span class='hs-varid'>x2</span><span class='hs-varop'>*</span><span class='hs-varid'>y2</span> <span class='hs-varop'>&gt;</span>     <span class='hs-conid'>V</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'>`cross`</span> <span class='hs-conid'>V</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x1</span><span class='hs-varop'>*</span><span class='hs-varid'>y2</span><span class='hs-comment'>-</span><span class='hs-varid'>x2</span><span class='hs-varop'>*</span><span class='hs-varid'>y1</span> <span class='hs-varop'>&gt;</span>-<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Vec</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Float</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>+<span class='hs-varop'>&gt;</span> <span class='hs-keyword'>instance</span> <span class='hs-conid'>Vector2D</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>Vec</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-conid'>CFloat</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^+^</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^+^</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^-^</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^-^</span><span class='hs-layout'>)</span> <span class='hs-varop'>&gt;</span>     <span class='hs-layout'>(</span><span class='hs-varop'>^*.</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-layout'>(</span><span class='hs-varop'>^*.</span><span class='hs-layout'>)</span>@@ -141,4 +142,4 @@ <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>dot</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-varid'>dot</span> <span class='hs-varop'>&gt;</span>     <span class='hs-varid'>cross</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>liftA2</span> <span class='hs-varid'>cross</span> </pre>-</body></html>+</div></body></html>
elerea-examples.cabal view
@@ -1,5 +1,5 @@ Name:                elerea-examples-Version:             1.0.0+Version:             1.0.1 Cabal-Version:       >= 1.2 Synopsis:            Example applications for Elerea Category:            reactivity, FRP
src/Breakout.lhs view
@@ -86,7 +86,7 @@ either be alive or dying.  Dying bricks also keep track of their fadeout level. -> data BrickState = Live | Dying !Double deriving (Eq,Show)+> data BrickState = Live | Dying !GLfloat deriving (Eq,Show)  The starting positions of the bricks.
src/Common/Vector.lhs view
@@ -3,7 +3,8 @@  This module contains a class for two-dimensional vectors, a strict datatype to instantiate it, and another instance for signals of the-same type.+same type.  We use CFloat as the coordinate type, because GLfloat is+its synonym.  > {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-} >@@ -11,8 +12,9 @@ > > import Control.Applicative > import FRP.Elerea+> import Foreign.C.Types >-> data Vec = V { getX :: !Float, getY :: !Float }+> data Vec = V { getX :: !CFloat, getY :: !CFloat } > > infixl 7 ^*. > infixl 7 .*^@@ -30,7 +32,7 @@ >     dot :: v -> v -> c >     cross :: v -> v -> c >-> instance Vector2D Vec Float where+> instance Vector2D Vec CFloat where >     V x1 y1 ^+^ V x2 y2 = V (x1+x2) (y1+y2) >     V x1 y1 ^-^ V x2 y2 = V (x1-x2) (y1-y2) >     V x y ^*. t = V (x*t) (y*t)@@ -39,7 +41,7 @@ >     V x1 y1 `dot` V x2 y2 = x1*y1+x2*y2 >     V x1 y1 `cross` V x2 y2 = x1*y2-x2*y1 >-> instance Vector2D (Signal Vec) (Signal Float) where+> instance Vector2D (Signal Vec) (Signal CFloat) where >     (^+^) = liftA2 (^+^) >     (^-^) = liftA2 (^-^) >     (^*.) = liftA2 (^*.)