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author | Corbin Simpson <[email protected]> | 2009-12-23 23:36:06 -0800 |
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committer | Corbin Simpson <[email protected]> | 2009-12-23 23:36:06 -0800 |
commit | 54ddf642dfaea3532b60c8239cb6a83950762e43 (patch) | |
tree | 412d4ead52637b7cbc584041bfe71622f3e308f3 /src/gallium/docs/build/html/tgsi.html | |
parent | 5bcd26c1725c5782875d329eb5f5637d4a95dd1f (diff) |
docs: Add all semantics to TGSI doc, regen.
Diffstat (limited to 'src/gallium/docs/build/html/tgsi.html')
-rw-r--r-- | src/gallium/docs/build/html/tgsi.html | 87 |
1 files changed, 79 insertions, 8 deletions
diff --git a/src/gallium/docs/build/html/tgsi.html b/src/gallium/docs/build/html/tgsi.html index 0dac00f25e0..7954e1de40e 100644 --- a/src/gallium/docs/build/html/tgsi.html +++ b/src/gallium/docs/build/html/tgsi.html @@ -861,13 +861,76 @@ is 0.</p> <p>The meanings of the individual semantic names are explained in the following sections.</p> </blockquote> -<div class="section" id="face"> -<h4>FACE<a class="headerlink" href="#face" title="Permalink to this headline">¶</a></h4> -<blockquote> -<p>Valid only in a fragment shader INPUT declaration.</p> -<p>FACE.x is negative when the primitive is back facing. FACE.x is positive -when the primitive is front facing.</p> -</blockquote> +<div class="section" id="tgsi-semantic-position"> +<h4>TGSI_SEMANTIC_POSITION<a class="headerlink" href="#tgsi-semantic-position" title="Permalink to this headline">¶</a></h4> +<p>Position, sometimes known as HPOS or WPOS for historical reasons, is the +location of the vertex in space, in <tt class="docutils literal"><span class="pre">(x,</span> <span class="pre">y,</span> <span class="pre">z,</span> <span class="pre">w)</span></tt> format. <tt class="docutils literal"><span class="pre">x</span></tt>, <tt class="docutils literal"><span class="pre">y</span></tt>, and <tt class="docutils literal"><span class="pre">z</span></tt> +are the Cartesian coordinates, and <tt class="docutils literal"><span class="pre">w</span></tt> is the homogenous coordinate and used +for the perspective divide, if enabled.</p> +<p>As a vertex shader output, position should be scaled to the viewport. When +used in fragment shaders, position will —</p> +<p>XXX — wait a minute. Should position be in [0,1] for x and y?</p> +<p>XXX additionally, is there a way to configure the perspective divide? it’s +accelerated on most chipsets AFAIK...</p> +<p>Position, if not specified, usually defaults to <tt class="docutils literal"><span class="pre">(0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">1)</span></tt>, and can +be partially specified as <tt class="docutils literal"><span class="pre">(x,</span> <span class="pre">y,</span> <span class="pre">0,</span> <span class="pre">1)</span></tt> or <tt class="docutils literal"><span class="pre">(x,</span> <span class="pre">y,</span> <span class="pre">z,</span> <span class="pre">1)</span></tt>.</p> +<p>XXX usually? can we solidify that?</p> +</div> +<div class="section" id="tgsi-semantic-color"> +<h4>TGSI_SEMANTIC_COLOR<a class="headerlink" href="#tgsi-semantic-color" title="Permalink to this headline">¶</a></h4> +<p>Colors are used to, well, color the primitives. Colors are always in +<tt class="docutils literal"><span class="pre">(r,</span> <span class="pre">g,</span> <span class="pre">b,</span> <span class="pre">a)</span></tt> format.</p> +<p>If alpha is not specified, it defaults to 1.</p> +</div> +<div class="section" id="tgsi-semantic-bcolor"> +<h4>TGSI_SEMANTIC_BCOLOR<a class="headerlink" href="#tgsi-semantic-bcolor" title="Permalink to this headline">¶</a></h4> +<p>Back-facing colors are only used for back-facing polygons, and are only valid +in vertex shader outputs. After rasterization, all polygons are front-facing +and COLOR and BCOLOR end up occupying the same slots in the fragment, so +all BCOLORs effectively become regular COLORs in the fragment shader.</p> +</div> +<div class="section" id="tgsi-semantic-fog"> +<h4>TGSI_SEMANTIC_FOG<a class="headerlink" href="#tgsi-semantic-fog" title="Permalink to this headline">¶</a></h4> +<p>The fog coordinate historically has been used to replace the depth coordinate +for generation of fog in dedicated fog blocks. Gallium, however, does not use +dedicated fog acceleration, placing it entirely in the fragment shader +instead.</p> +<p>The fog coordinate should be written in <tt class="docutils literal"><span class="pre">(f,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">1)</span></tt> format. Only the first +component matters when writing from the vertex shader; the driver will ensure +that the coordinate is in this format when used as a fragment shader input.</p> +</div> +<div class="section" id="tgsi-semantic-psize"> +<h4>TGSI_SEMANTIC_PSIZE<a class="headerlink" href="#tgsi-semantic-psize" title="Permalink to this headline">¶</a></h4> +<p>PSIZE, or point size, is used to specify point sizes per-vertex. It should +be in <tt class="docutils literal"><span class="pre">(p,</span> <span class="pre">n,</span> <span class="pre">x,</span> <span class="pre">f)</span></tt> format, where <tt class="docutils literal"><span class="pre">p</span></tt> is the point size, <tt class="docutils literal"><span class="pre">n</span></tt> is the minimum +size, <tt class="docutils literal"><span class="pre">x</span></tt> is the maximum size, and <tt class="docutils literal"><span class="pre">f</span></tt> is the fade threshold.</p> +<p>XXX this is arb_vp. is this what we actually do? should double-check...</p> +<p>When using this semantic, be sure to set the appropriate state in the +<a class="reference external" href="cso/rasterizer.html#rasterizer"><em>Rasterizer</em></a> first.</p> +</div> +<div class="section" id="tgsi-semantic-generic"> +<h4>TGSI_SEMANTIC_GENERIC<a class="headerlink" href="#tgsi-semantic-generic" title="Permalink to this headline">¶</a></h4> +<p>Generic semantics are nearly always used for texture coordinate attributes, +in <tt class="docutils literal"><span class="pre">(s,</span> <span class="pre">t,</span> <span class="pre">r,</span> <span class="pre">q)</span></tt> format. <tt class="docutils literal"><span class="pre">t</span></tt> and <tt class="docutils literal"><span class="pre">r</span></tt> may be unused for certain kinds +of lookups, and <tt class="docutils literal"><span class="pre">q</span></tt> is the level-of-detail bias for biased sampling.</p> +<p>These attributes are called “generic” because they may be used for anything +else, including parameters, texture generation information, or anything that +can be stored inside a four-component vector.</p> +</div> +<div class="section" id="tgsi-semantic-normal"> +<h4>TGSI_SEMANTIC_NORMAL<a class="headerlink" href="#tgsi-semantic-normal" title="Permalink to this headline">¶</a></h4> +<p>XXX no clue.</p> +</div> +<div class="section" id="tgsi-semantic-face"> +<h4>TGSI_SEMANTIC_FACE<a class="headerlink" href="#tgsi-semantic-face" title="Permalink to this headline">¶</a></h4> +<p>FACE is the facing bit, to store the facing information for the fragment +shader. <tt class="docutils literal"><span class="pre">(f,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">1)</span></tt> is the format. The first component will be positive +when the fragment is front-facing, and negative when the component is +back-facing.</p> +</div> +<div class="section" id="tgsi-semantic-edgeflag"> +<h4>TGSI_SEMANTIC_EDGEFLAG<a class="headerlink" href="#tgsi-semantic-edgeflag" title="Permalink to this headline">¶</a></h4> +<p>XXX no clue</p> </div> </div> </div> @@ -898,7 +961,15 @@ when the primitive is front facing.</p> </li> <li><a class="reference external" href="#other-tokens">Other tokens</a><ul> <li><a class="reference external" href="#declaration-semantic">Declaration Semantic</a><ul> -<li><a class="reference external" href="#face">FACE</a></li> +<li><a class="reference external" href="#tgsi-semantic-position">TGSI_SEMANTIC_POSITION</a></li> +<li><a class="reference external" href="#tgsi-semantic-color">TGSI_SEMANTIC_COLOR</a></li> +<li><a class="reference external" href="#tgsi-semantic-bcolor">TGSI_SEMANTIC_BCOLOR</a></li> +<li><a class="reference external" href="#tgsi-semantic-fog">TGSI_SEMANTIC_FOG</a></li> +<li><a class="reference external" href="#tgsi-semantic-psize">TGSI_SEMANTIC_PSIZE</a></li> +<li><a class="reference external" href="#tgsi-semantic-generic">TGSI_SEMANTIC_GENERIC</a></li> +<li><a class="reference external" href="#tgsi-semantic-normal">TGSI_SEMANTIC_NORMAL</a></li> +<li><a class="reference external" href="#tgsi-semantic-face">TGSI_SEMANTIC_FACE</a></li> +<li><a class="reference external" href="#tgsi-semantic-edgeflag">TGSI_SEMANTIC_EDGEFLAG</a></li> </ul> </li> </ul> |