arb-glsl workgroupUpdate

Bill Licea-Kane

ATI Research, Inc.

arb-glsl workgroupOpenGL Shading Language• OpenGL Shading Language• OpenGL ES Shading Language

– EVOLVING TOGETHER IN PARALLEL

arb-glsl workgroupOpenGL Shading Language

#version 120• Can link shaders with mixed versions• Special Variables• Qualifiers• Minor changes (some backward incompatible)

– Names– Function Signatures– Arrays– Matrices

• ARB_texture_shader_lod

arb-glsl workgroupOpenGL Shading Language• built-in fragment special variables

– Based on OpenGL ES 2.0– Values are undefined if GL_POINT_SPRITE disabled

gl_PointCoord;

• qualifier

vec4 centroid varying Texcoord;

arb-glsl workgroupOpenGL Shading Language

arb-glsl workgroupOpenGL Shading Language

• Names – slight changes from #version 110– C++ like– Names hide names of all types

• Functions, Variables, Structures– Can declare names within a scope

• Exception – local functions declarations disallowed• Exception – can not redeclare within a scope

– Built-in functions in “outermost scope”• A local name hides *ALL* outer names

arb-glsl workgroupOpenGL Shading Language

• Example

#version 120

// ...

vec4 texture2D( sampler2D s, vec4 P )

{

return vec4( 1.0, 0.0, 1.0, 1.0 );

}

// ...

vec4 texture2D = texture2D( tex0, P.st );

arb-glsl workgroupOpenGL Shading Language• Signature matching• First try to find an exact match• Else try limited implicit constructors:

– int float– ivec2 vec2– ivec3 vec3– ivec4 vec4

• If multiple implicit matches, error

arb-glsl workgroupOpenGL Shading Language• Arrays

– Now first class– ==, !=, = (but must have explicit size)– Array constructors

float[7]( 0.0,1.0,2.0,3.0,4.0,5.0,6.0 )float[]( 0.0,1.0,2.0,3.0,4.0,5.0,6.0 )

float a[] = float[]( 0.0, 1.0, 2.0 );

arb-glsl workgroupOpenGL Shading Language• Matrices

– non-square permitted

mat2x3 // 2 columns by 3 rows

outerProduct()

transpose()– Additional constructors

arb-glsl workgroupOpenGL Shading Language• built-in functions

– Based on ATI_shader_texture_lod

texture2DLod( sampler2D s, vec2 P,

float Lod );

texture2DGradARB( sampler2D s, vec2 P,

vec2 dPdx, vec2 dPdy );

texture2DProjGradARB( sampler2D s, vec2 P,

vec2 dPdx, vec2 dPdy );

arb-glsl workgroupPixel grids and area operators