The High Level Shader Language or High Level Shading Language (HLSL) is a proprietary shading language developed by Microsoft for use with the Microsoft Direct3D API. It is analogous to the GLSL shading language used with the OpenGL standard. It is the same as the Nvidia Cg shading language, as it was developed alongside it.
HLSL programs come in three forms, vertex shaders, geometry shaders, and pixel (or fragment) shaders. A vertex shader is executed for each vertex that is submitted by the application, and is primarily responsible for transforming the vertex from object space to view space, generating texture coordinates, and calculating lighting coefficients such as the vertex's tangent, binormal and normal vectors. When a group of vertices (normally 3, to form a triangle) come through the vertex shader, their output position is interpolated to form pixels within its area; this process is known as rasterisation. Each of these pixels comes through the pixel shader, whereby the resultant screen colour is calculated.
Optionally, an application using a Direct3D 10 interface and Direct3D 10 hardware may also specify a geometry shader. This shader takes as its input the three vertices of a triangle and uses this data to generate (or tessellate) additional triangles, which are each then sent to the rasterizer.
Famous quotes containing the words high, level and/or language:
“Gifts of one loved me,—
‘T was high time they came;
When he ceased to love me,
Time they stopped for shame.”
—Ralph Waldo Emerson (1803–1882)
“Your mock saint who stands in a niche is not a woman if she have not suffered, still less a woman if she have not sinned. Fall at the feet of your idol as you wish, but drag her down to your level after that—the only level she should ever reach, that of your heart.”
—Emmuska, Baroness Orczy (1865–1947)
“I suggested to them also the great desirability of a general knowledge on the Island of the English language. They are under an English speaking government and are a part of the territory of an English speaking nation.... While I appreciated the desirability of maintaining their grasp on the Spanish language, the beauty of that language and the richness of its literature, that as a practical matter for them it was quite necessary to have a good comprehension of English.”
—Calvin Coolidge (1872–1933)