<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ --> <title>Graphics/Rendering/OpenGL/GL/LineSegments.hs</title> <link type='text/css' rel='stylesheet' href='hscolour.css' /> </head> <body> <pre><a name="line-1"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-2"></a><span class='hs-comment'>-- |</span> <a name="line-3"></a><span class='hs-comment'>-- Module : Graphics.Rendering.OpenGL.GL.LineSegments</span> <a name="line-4"></a><span class='hs-comment'>-- Copyright : (c) Sven Panne 2002-2009</span> <a name="line-5"></a><span class='hs-comment'>-- License : BSD-style (see the file libraries/OpenGL/LICENSE)</span> <a name="line-6"></a><span class='hs-comment'>-- </span> <a name="line-7"></a><span class='hs-comment'>-- Maintainer : sven.panne@aedion.de</span> <a name="line-8"></a><span class='hs-comment'>-- Stability : stable</span> <a name="line-9"></a><span class='hs-comment'>-- Portability : portable</span> <a name="line-10"></a><span class='hs-comment'>--</span> <a name="line-11"></a><span class='hs-comment'>-- This module corresponds to section 3.4 (Line Segments) of the OpenGL 2.1</span> <a name="line-12"></a><span class='hs-comment'>-- specs.</span> <a name="line-13"></a><span class='hs-comment'>--</span> <a name="line-14"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-15"></a> <a name="line-16"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>LineSegments</span> <span class='hs-layout'>(</span> <a name="line-17"></a> <span class='hs-comment'>-- * Line Rasterization</span> <a name="line-18"></a> <span class='hs-varid'>lineWidth</span><span class='hs-layout'>,</span> <a name="line-19"></a> <a name="line-20"></a> <span class='hs-comment'>-- * Line Stipple</span> <a name="line-21"></a> <span class='hs-varid'>lineStipple</span><span class='hs-layout'>,</span> <a name="line-22"></a> <a name="line-23"></a> <span class='hs-comment'>-- * Line Antialiasing</span> <a name="line-24"></a> <span class='hs-varid'>lineSmooth</span><span class='hs-layout'>,</span> <a name="line-25"></a> <a name="line-26"></a> <span class='hs-comment'>-- * Implementation-Dependent Limits</span> <a name="line-27"></a> <span class='hs-varid'>aliasedLineWidthRange</span><span class='hs-layout'>,</span> <span class='hs-varid'>smoothLineWidthRange</span><span class='hs-layout'>,</span> <span class='hs-varid'>smoothLineWidthGranularity</span> <a name="line-28"></a><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-29"></a> <a name="line-30"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span> <span class='hs-layout'>(</span> <span class='hs-varid'>liftM2</span> <span class='hs-layout'>)</span> <a name="line-31"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>Capability</span> <span class='hs-layout'>(</span> <a name="line-32"></a> <span class='hs-conid'>EnableCap</span><span class='hs-layout'>(</span><span class='hs-conid'>CapLineSmooth</span><span class='hs-layout'>,</span><span class='hs-conid'>CapLineStipple</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>makeCapability</span><span class='hs-layout'>,</span> <span class='hs-varid'>makeStateVarMaybe</span> <span class='hs-layout'>)</span> <a name="line-33"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>BasicTypes</span> <span class='hs-layout'>(</span> <a name="line-34"></a> <span class='hs-conid'>GLint</span><span class='hs-layout'>,</span> <span class='hs-conid'>GLushort</span><span class='hs-layout'>,</span> <span class='hs-conid'>GLfloat</span><span class='hs-layout'>,</span> <span class='hs-conid'>Capability</span> <span class='hs-layout'>)</span> <a name="line-35"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>QueryUtils</span> <span class='hs-layout'>(</span> <a name="line-36"></a> <span class='hs-conid'>GetPName</span><span class='hs-layout'>(</span><span class='hs-conid'>GetLineWidth</span><span class='hs-layout'>,</span><span class='hs-conid'>GetAliasedLineWidthRange</span><span class='hs-layout'>,</span><span class='hs-conid'>GetSmoothLineWidthRange</span><span class='hs-layout'>,</span> <a name="line-37"></a> <span class='hs-conid'>GetSmoothLineWidthGranularity</span><span class='hs-layout'>,</span><span class='hs-conid'>GetLineStippleRepeat</span><span class='hs-layout'>,</span> <a name="line-38"></a> <span class='hs-conid'>GetLineStipplePattern</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <a name="line-39"></a> <span class='hs-varid'>getInteger1</span><span class='hs-layout'>,</span> <span class='hs-varid'>getFloat1</span><span class='hs-layout'>,</span> <span class='hs-varid'>getFloat2</span> <span class='hs-layout'>)</span> <a name="line-40"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Graphics</span><span class='hs-varop'>.</span><span class='hs-conid'>Rendering</span><span class='hs-varop'>.</span><span class='hs-conid'>OpenGL</span><span class='hs-varop'>.</span><span class='hs-conid'>GL</span><span class='hs-varop'>.</span><span class='hs-conid'>StateVar</span> <span class='hs-layout'>(</span> <a name="line-41"></a> <span class='hs-conid'>GettableStateVar</span><span class='hs-layout'>,</span> <span class='hs-varid'>makeGettableStateVar</span><span class='hs-layout'>,</span> <span class='hs-conid'>StateVar</span><span class='hs-layout'>,</span> <span class='hs-varid'>makeStateVar</span> <span class='hs-layout'>)</span> <a name="line-42"></a> <a name="line-43"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-44"></a> <a name="line-45"></a><span class='hs-comment'>-- | 'lineWidth' contains the rasterized width of both aliased and antialiased</span> <a name="line-46"></a><span class='hs-comment'>-- lines. The initial value is 1. Using a line width other than 1 has different</span> <a name="line-47"></a><span class='hs-comment'>-- effects, depending on whether line antialiasing is enabled (see</span> <a name="line-48"></a><span class='hs-comment'>-- 'lineSmooth'). Line antialiasing is initially disabled.</span> <a name="line-49"></a><span class='hs-comment'>--</span> <a name="line-50"></a><span class='hs-comment'>-- If line antialiasing is disabled, the actual width is determined by rounding</span> <a name="line-51"></a><span class='hs-comment'>-- the supplied width to the nearest integer. (If the rounding results in the</span> <a name="line-52"></a><span class='hs-comment'>-- value 0, it is as if the line width were 1.) If /delta x/ >= /delta y/, /i/</span> <a name="line-53"></a><span class='hs-comment'>-- pixels are filled in each column that is rasterized, where /i/ is the</span> <a name="line-54"></a><span class='hs-comment'>-- rounded value of 'lineWidth'. Otherwise, /i/ pixels are filled in each row</span> <a name="line-55"></a><span class='hs-comment'>-- that is rasterized.</span> <a name="line-56"></a><span class='hs-comment'>--</span> <a name="line-57"></a><span class='hs-comment'>-- If antialiasing is enabled, line rasterization produces a fragment for each</span> <a name="line-58"></a><span class='hs-comment'>-- pixel square that intersects the region lying within the rectangle having</span> <a name="line-59"></a><span class='hs-comment'>-- width equal to the current line width, length equal to the actual length of</span> <a name="line-60"></a><span class='hs-comment'>-- the line, and centered on the mathematical line segment. The coverage value</span> <a name="line-61"></a><span class='hs-comment'>-- for each fragment is the window coordinate area of the intersection of the</span> <a name="line-62"></a><span class='hs-comment'>-- rectangular region with the corresponding pixel square. This value is saved</span> <a name="line-63"></a><span class='hs-comment'>-- and used in the final rasterization step.</span> <a name="line-64"></a><span class='hs-comment'>--</span> <a name="line-65"></a><span class='hs-comment'>-- Not all widths can be supported when line antialiasing is enabled. If an</span> <a name="line-66"></a><span class='hs-comment'>-- unsupported width is requested, the nearest supported width is used. Only</span> <a name="line-67"></a><span class='hs-comment'>-- width 1 is guaranteed to be supported; others depend on the implementation.</span> <a name="line-68"></a><span class='hs-comment'>-- Likewise, there is a range for aliased line widths as well. To query the</span> <a name="line-69"></a><span class='hs-comment'>-- range of supported widths of antialiased lines and the size difference</span> <a name="line-70"></a><span class='hs-comment'>-- between supported widths within the range, query 'smoothLineWidthRange' and</span> <a name="line-71"></a><span class='hs-comment'>-- 'smoothLineWidthGranularity', respectively. For aliased lines, query the</span> <a name="line-72"></a><span class='hs-comment'>-- supported range with 'aliasedLineWidthRange'.</span> <a name="line-73"></a><span class='hs-comment'>--</span> <a name="line-74"></a><span class='hs-comment'>-- The line width specified when 'lineWidth' is set is always returned when it</span> <a name="line-75"></a><span class='hs-comment'>-- is queried. Clamping and rounding for aliased and antialiased lines have no</span> <a name="line-76"></a><span class='hs-comment'>-- effect on the specified value.</span> <a name="line-77"></a><span class='hs-comment'>--</span> <a name="line-78"></a><span class='hs-comment'>-- A non-antialiased line width may be clamped to an implementation-dependent</span> <a name="line-79"></a><span class='hs-comment'>-- maximum. Query 'aliasedLineWidthRange' to determine the maximum width.</span> <a name="line-80"></a><span class='hs-comment'>--</span> <a name="line-81"></a><span class='hs-comment'>-- An 'Graphics.Rendering.OpenGL.GLU.Errors.InvalidValue' is generated if</span> <a name="line-82"></a><span class='hs-comment'>-- 'lineWidth' is set to a value less than or equal to zero.</span> <a name="line-83"></a><span class='hs-comment'>--</span> <a name="line-84"></a><span class='hs-comment'>-- An 'Graphics.Rendering.OpenGL.GLU.Errors.InvalidOperation' is generated if</span> <a name="line-85"></a><span class='hs-comment'>-- 'lineWidth' is set during</span> <a name="line-86"></a><span class='hs-comment'>-- 'Graphics.Rendering.OpenGL.GL.BeginEnd.renderPrimitive'.</span> <a name="line-87"></a> <a name="line-88"></a><a name="lineWidth"></a><span class='hs-definition'>lineWidth</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>StateVar</span> <span class='hs-conid'>GLfloat</span> <a name="line-89"></a><span class='hs-definition'>lineWidth</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>makeStateVar</span> <span class='hs-layout'>(</span><span class='hs-varid'>getFloat1</span> <span class='hs-varid'>id</span> <span class='hs-conid'>GetLineWidth</span><span class='hs-layout'>)</span> <span class='hs-varid'>glLineWidth</span> <a name="line-90"></a> <a name="line-91"></a><span class='hs-keyword'>foreign</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>CALLCONV</span> <span class='hs-keyword'>unsafe</span> <span class='hs-str'>"glLineWidth"</span> <span class='hs-varid'>glLineWidth</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GLfloat</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <a name="line-92"></a> <a name="line-93"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-94"></a> <a name="line-95"></a><span class='hs-comment'>-- | Line stippling masks out certain fragments produced by rasterization; those</span> <a name="line-96"></a><span class='hs-comment'>-- fragments will not be drawn. The masking is achieved by using three</span> <a name="line-97"></a><span class='hs-comment'>-- parameters: the repeat count (1st element of the 'lineStipple' pair, clamped</span> <a name="line-98"></a><span class='hs-comment'>-- to the range [ 1 .. 256 ]), the 16-bit line stipple pattern (2nd element),</span> <a name="line-99"></a><span class='hs-comment'>-- and an integer stipple counter /s/.</span> <a name="line-100"></a><span class='hs-comment'>--</span> <a name="line-101"></a><span class='hs-comment'>-- The counter /s/ is reset to 0 at before the first action during</span> <a name="line-102"></a><span class='hs-comment'>-- 'Graphics.Rendering.OpenGL.GL.BeginEnd.renderPrimitive' is called and before</span> <a name="line-103"></a><span class='hs-comment'>-- each line segment during</span> <a name="line-104"></a><span class='hs-comment'>-- 'Graphics.Rendering.OpenGL.GL.BeginEnd.renderPrimitive' is generated. It is</span> <a name="line-105"></a><span class='hs-comment'>-- incremented after each fragment of a unit width aliased line segment is</span> <a name="line-106"></a><span class='hs-comment'>-- generated or after each /i/ fragments of an /i/ width line segment are</span> <a name="line-107"></a><span class='hs-comment'>-- generated. The /i/ fragments associated with count /s/ are masked out if</span> <a name="line-108"></a><span class='hs-comment'>-- @'Data.Bits.testBit' /pattern/ (( /s/ \/ /factor/ ) /mod/ 16)@ is 'False',</span> <a name="line-109"></a><span class='hs-comment'>-- otherwise these fragments are sent to the frame buffer. Bit zero of the</span> <a name="line-110"></a><span class='hs-comment'>-- pattern is the least significant bit, i.e. it is used first.</span> <a name="line-111"></a><span class='hs-comment'>--</span> <a name="line-112"></a><span class='hs-comment'>-- Antialiased lines are treated as a sequence of rectangles of height 1 for</span> <a name="line-113"></a><span class='hs-comment'>-- purposes of stippling. Whether rectangle /s/ is rasterized or not depends on</span> <a name="line-114"></a><span class='hs-comment'>-- the fragment rule described for aliased lines, counting rectangles rather</span> <a name="line-115"></a><span class='hs-comment'>-- than groups of fragments.</span> <a name="line-116"></a><span class='hs-comment'>--</span> <a name="line-117"></a><span class='hs-comment'>-- The initial value of 'lineStipple' is 'Nothing', i.e. line stippling is</span> <a name="line-118"></a><span class='hs-comment'>-- disabled.</span> <a name="line-119"></a><span class='hs-comment'>--</span> <a name="line-120"></a><span class='hs-comment'>-- An 'Graphics.Rendering.OpenGL.GLU.Errors.InvalidOperation' is generated if</span> <a name="line-121"></a><span class='hs-comment'>-- 'lineStipple' is set during</span> <a name="line-122"></a><span class='hs-comment'>-- 'Graphics.Rendering.OpenGL.GL.BeginEnd.renderPrimitive'.</span> <a name="line-123"></a> <a name="line-124"></a><a name="lineStipple"></a><span class='hs-definition'>lineStipple</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>StateVar</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>GLint</span><span class='hs-layout'>,</span> <span class='hs-conid'>GLushort</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <a name="line-125"></a><span class='hs-definition'>lineStipple</span> <span class='hs-keyglyph'>=</span> <a name="line-126"></a> <span class='hs-varid'>makeStateVarMaybe</span> <a name="line-127"></a> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-conid'>CapLineStipple</span><span class='hs-layout'>)</span> <a name="line-128"></a> <span class='hs-layout'>(</span><span class='hs-varid'>liftM2</span> <span class='hs-conid'>(,)</span> <span class='hs-layout'>(</span><span class='hs-varid'>getInteger1</span> <span class='hs-varid'>id</span> <span class='hs-conid'>GetLineStippleRepeat</span><span class='hs-layout'>)</span> <a name="line-129"></a> <span class='hs-layout'>(</span><span class='hs-varid'>getInteger1</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-conid'>GetLineStipplePattern</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <a name="line-130"></a> <span class='hs-layout'>(</span><span class='hs-varid'>uncurry</span> <span class='hs-varid'>glLineStipple</span><span class='hs-layout'>)</span> <a name="line-131"></a> <a name="line-132"></a><span class='hs-keyword'>foreign</span> <span class='hs-keyword'>import</span> <span class='hs-conid'>CALLCONV</span> <span class='hs-keyword'>unsafe</span> <span class='hs-str'>"glLineStipple"</span> <span class='hs-varid'>glLineStipple</span> <span class='hs-keyglyph'>::</span> <a name="line-133"></a> <span class='hs-conid'>GLint</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>GLushort</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <a name="line-134"></a> <a name="line-135"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-136"></a> <a name="line-137"></a><span class='hs-comment'>-- | Controls whether line antialiasing is enabled. The initial state is</span> <a name="line-138"></a><span class='hs-comment'>-- 'Graphics.Rendering.OpenGL.GL.BasicTypes.Disabled'.</span> <a name="line-139"></a> <a name="line-140"></a><a name="lineSmooth"></a><span class='hs-definition'>lineSmooth</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>StateVar</span> <span class='hs-conid'>Capability</span> <a name="line-141"></a><span class='hs-definition'>lineSmooth</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>makeCapability</span> <span class='hs-conid'>CapLineSmooth</span> <a name="line-142"></a> <a name="line-143"></a><span class='hs-comment'>--------------------------------------------------------------------------------</span> <a name="line-144"></a> <a name="line-145"></a><span class='hs-comment'>-- | The smallest and largest supported width of aliased lines.</span> <a name="line-146"></a> <a name="line-147"></a><a name="aliasedLineWidthRange"></a><span class='hs-definition'>aliasedLineWidthRange</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GettableStateVar</span> <span class='hs-layout'>(</span><span class='hs-conid'>GLfloat</span><span class='hs-layout'>,</span> <span class='hs-conid'>GLfloat</span><span class='hs-layout'>)</span> <a name="line-148"></a><span class='hs-definition'>aliasedLineWidthRange</span> <span class='hs-keyglyph'>=</span> <a name="line-149"></a> <span class='hs-varid'>makeGettableStateVar</span> <span class='hs-varop'>$</span> <span class='hs-varid'>getFloat2</span> <span class='hs-conid'>(,)</span> <span class='hs-conid'>GetAliasedLineWidthRange</span> <a name="line-150"></a> <a name="line-151"></a><span class='hs-comment'>-- | The smallest and largest supported width of antialiased lines.</span> <a name="line-152"></a> <a name="line-153"></a><a name="smoothLineWidthRange"></a><span class='hs-definition'>smoothLineWidthRange</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GettableStateVar</span> <span class='hs-layout'>(</span><span class='hs-conid'>GLfloat</span><span class='hs-layout'>,</span> <span class='hs-conid'>GLfloat</span><span class='hs-layout'>)</span> <a name="line-154"></a><span class='hs-definition'>smoothLineWidthRange</span> <span class='hs-keyglyph'>=</span> <a name="line-155"></a> <span class='hs-varid'>makeGettableStateVar</span> <span class='hs-varop'>$</span> <span class='hs-varid'>getFloat2</span> <span class='hs-conid'>(,)</span> <span class='hs-conid'>GetSmoothLineWidthRange</span> <a name="line-156"></a> <a name="line-157"></a><span class='hs-comment'>-- | The antialiased line width granularity, i.e. the size difference between</span> <a name="line-158"></a><span class='hs-comment'>-- supported widths.</span> <a name="line-159"></a> <a name="line-160"></a><a name="smoothLineWidthGranularity"></a><span class='hs-definition'>smoothLineWidthGranularity</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>GettableStateVar</span> <span class='hs-conid'>GLfloat</span> <a name="line-161"></a><span class='hs-definition'>smoothLineWidthGranularity</span> <span class='hs-keyglyph'>=</span> <a name="line-162"></a> <span class='hs-varid'>makeGettableStateVar</span> <span class='hs-varop'>$</span> <span class='hs-varid'>getFloat1</span> <span class='hs-varid'>id</span> <span class='hs-conid'>GetSmoothLineWidthGranularity</span> </pre></body> </html>
