[Piglit] [PATCH] Test that there are 8 clip planes/distances in GLSL 1.30.

Ian Romanick idr at freedesktop.org
Mon Sep 19 10:49:52 PDT 2011


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On 09/13/2011 02:54 PM, Paul Berry wrote:
> The clipping tests previously in Piglit only tested the first 6 
> clipping planes, since prior to GLSL 1.30, a conforming
> implementation was allowed to only support 6 clipping planes.
> However, in GLSL 1.30, the minimum value of gl_MaxClipDistances and
> gl_MaxClipPlanes was increased to 8.
> 
> This patch adds tests to verify that if the implementation reports
> a GLSL version of at least 1.30, gl_MaxClipDistances and 
> gl_MaxClipPlanes are both at least 8.  It also modifies 
> vs-clip-distance-all-planes-enabled.shader_test to exercise all 8 
> clipping planes.
> 
> The previous implementation of 
> vs-clip-distance-all-planes-enabled.shader_test used to also
> verify, as a side effect, that gl_ClipDistance could be implicitly
> sized.  The new version does not (it requires gl_ClipDistance to be
> explicitly sized, since it indexes into it using a loop variable).
> So I've added a new test,
> vs-clip-distance-implicitly-sized.shader_test, to verify this.
> 
> Tested using the nVidia proprietary Linux driver.

I made some comments about max-clip-distances.shader_test (which also
apply to max-clip-planes.shader_test) below.

The changes to shader_runner and the other tests look fine.  You can
consider them

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

if you want to split them out and push them sooner rather than later.

> --- tests/shaders/shader_runner.c                      |    2 + 
> .../clipping/max-clip-distances.shader_test        |   54
> ++++++++++++++ .../execution/clipping/max-clip-planes.shader_test |
> 54 ++++++++++++++ 
> ...vs-clip-distance-all-planes-enabled.shader_test |   76
> ++++++++++---------- 
> .../vs-clip-distance-implicitly-sized.shader_test  |   67
> +++++++++++++++++ tests/util/glew.h
> |    2 + 6 files changed, 218 insertions(+), 37 deletions(-) create
> mode 100644
> tests/spec/glsl-1.30/execution/clipping/max-clip-distances.shader_test
>
> 
create mode 100644
tests/spec/glsl-1.30/execution/clipping/max-clip-planes.shader_test
> create mode 100644
> tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-implicitly-sized.shader_test
>
>  diff --git a/tests/shaders/shader_runner.c
> b/tests/shaders/shader_runner.c index cde5ae3..a46ea4d 100644 ---
> a/tests/shaders/shader_runner.c +++
> b/tests/shaders/shader_runner.c @@ -819,6 +819,8 @@ struct
> enable_table { { "GL_CLIP_PLANE3", GL_CLIP_PLANE3 }, {
> "GL_CLIP_PLANE4", GL_CLIP_PLANE4 }, { "GL_CLIP_PLANE5",
> GL_CLIP_PLANE5 }, +	{ "GL_CLIP_PLANE6", GL_CLIP_PLANE6 }, +	{
> "GL_CLIP_PLANE7", GL_CLIP_PLANE7 }, { NULL, 0 } };
> 
> diff --git
> a/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.shader_test
> b/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.shader_test
>
> 
new file mode 100644
> index 0000000..d593fbf --- /dev/null +++
> b/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.shader_test
>
> 
@@ -0,0 +1,54 @@
> +# [description] +# Verify correct behavior of
> gl_MaxClipDistances. +# +# From section the GLSL 1.30 spec, section
> 7.4 (Built-In Constants): +# +#   "The following built-in constants
> are provided to vertex and +#   fragment shaders. The actual values
> used are implementation +#   dependent, but must be at least the
> value shown. +# +#   ... +# +#   const int gl_MaxClipDistances =
> 8;" +# +# This test verifies that gl_MaxClipDistances has the same
> value in +# both the vertex and fragment shader, and that this
> value is at least +# 8. + +[require] +GLSL >= 1.30 + +[vertex
> shader] +#version 130 + +out float maxClipDistances; + +void
> main() +{ +	gl_Position = gl_Vertex; + +	maxClipDistances =
> gl_MaxClipDistances; +} + +[fragment shader] +#version 130 + +in
> float maxClipDistances; + +void main() +{ +	if (maxClipDistances !=
> gl_MaxClipDistances) {

This is valid, but probably not what we actually want.  Shouldn't we
pass maxClipDistances as an int?  It means that the 'flat'
interpolation qualifier will have to be used, and that may cause the
test to fail on Mesa now even though we set gl_MaxClipDistances correctly.

Also, this test is really checking that gl_MaxClipDistances is set the
same in the VS and FS.  I'm not sure how useful that is.  It seems
like we want to query GL_MAX_CLIP_DISTANCES from the API and pass that
as a uniform.  Maybe that's an additional test?

> +		// Red: gl_MaxClipDistances values don't match +		gl_FragColor =
> vec4(1.0, 0.0, 0.0, 1.0); +	} else if (gl_MaxClipDistances < 8) { +
> // Yellow: gl_MaxClipDistances is too small +		gl_FragColor =
> vec4(1.0, 1.0, 0.0, 1.0); +	} else { +		// Green: ok +
> gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); +	} +} + +[test] +draw
> rect -1 -1 2 2 +probe all rgba 0.0 1.0 0.0 1.0 diff --git
> a/tests/spec/glsl-1.30/execution/clipping/max-clip-planes.shader_test
> b/tests/spec/glsl-1.30/execution/clipping/max-clip-planes.shader_test
>
> 
new file mode 100644
> index 0000000..2d7c987 --- /dev/null +++
> b/tests/spec/glsl-1.30/execution/clipping/max-clip-planes.shader_test
>
> 
@@ -0,0 +1,54 @@
> +# [description] +# Verify correct behavior of gl_MaxClipPlanes. 
> +# +# From section the GLSL 1.30 spec, section 7.4 (Built-In
> Constants): +# +#   "The following built-in constants are provided
> to vertex and +#   fragment shaders. The actual values used are
> implementation +#   dependent, but must be at least the value
> shown. +# +#   ... +# +#   const int gl_MaxClipPlanes = 8; //
> deprecated" +# +# This test verifies that gl_MaxClipPlanes has the
> same value in +# both the vertex and fragment shader, and that this
> value is at least +# 8. + +[require] +GLSL >= 1.30 + +[vertex
> shader] +#version 130 + +out float maxClipPlanes; + +void main() 
> +{ +	gl_Position = gl_Vertex; + +	maxClipPlanes =
> gl_MaxClipPlanes; +} + +[fragment shader] +#version 130 + +in float
> maxClipPlanes; + +void main() +{ +	if (maxClipPlanes !=
> gl_MaxClipPlanes) { +		// Red: gl_MaxClipPlanes values don't match 
> +		gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); +	} else if
> (gl_MaxClipPlanes < 8) { +		// Yellow: gl_MaxClipPlanes is too
> small +		gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0); +	} else { +		//
> Green: ok +		gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); +	} +} + 
> +[test] +draw rect -1 -1 2 2 +probe all rgba 0.0 1.0 0.0 1.0 diff
> --git
> a/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-all-planes-enabled.shader_test
> b/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-all-planes-enabled.shader_test
>
> 
index db294d5..88f37ec 100644
> ---
> a/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-all-planes-enabled.shader_test
>
> 
+++
b/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-all-planes-enabled.shader_test
> @@ -1,39 +1,35 @@ # [description] -# Use all 6 gl_ClipDistance
> values to clip a rectangle to a hexagon shape. +# Use all 8
> gl_ClipDistance values to clip a rectangle to an octagon shape. # 
> -# This also serves as a test that gl_ClipDistance may be
> implicitly -# sized, as specified in section 7.1 (Vertex Shader
> Special Variables) -# of the GLSL 1.30 spec: -# -#   The
> gl_ClipDistance array is predeclared as unsized and must be -#
> sized by the shader either redeclaring it with a size or indexing 
> -#   it only with integral constant expressions. This needs to size
> the -#   array to include all the clip planes that are enabled via
> the -#   OpenGL API; if the size does not include all enabled
> planes, -#   results are undefined. The size can be at most -#
> gl_MaxClipDistances. The number of varying components (see -#
> gl_MaxVaryingComponents) consumed by gl_ClipDistance will match -#
> the size of the array, no matter how many planes are enabled. The 
> -#   shader must also set all values in gl_ClipDistance that have
> been -#   enabled via the OpenGL API, or results are undefined.
> Values -#   written into gl_ClipDistance for planes that are not
> enabled have -#   no effect. +# The octagon is centered at (0.5,
> 0.5), and has a small radius +# (distance from center to
> perpendicular edge) of 0.4.
> 
> [require] GLSL >= 1.30
> 
> [vertex shader] #version 130 + +out float gl_ClipDistance[8]; + 
> void main(void) { gl_Position = gl_ModelViewProjectionMatrix *
> gl_Vertex;
> 
> -	gl_ClipDistance[0] = gl_Vertex.y - 0.25; -	gl_ClipDistance[1] =
> gl_Vertex.y - gl_Vertex.x + 0.4; -	gl_ClipDistance[2] = 1.4 -
> gl_Vertex.x - gl_Vertex.y; -	gl_ClipDistance[3] = 0.75 -
> gl_Vertex.y; -	gl_ClipDistance[4] = gl_Vertex.x - gl_Vertex.y +
> 0.4; -	gl_ClipDistance[5] = gl_Vertex.x + gl_Vertex.y - 0.6; +	//
> Compute 2D cordinates relative to a center point of (0.5, +	//
> 0.5). +	vec2 coord = gl_Vertex.xy - vec2(0.5, 0.5); + +	for (int i
> = 0; i < 8; ++i) { +		// Compute a unit vector in the direction
> i*45deg from +		// the x axis. +		float angle =
> i*(3.141592653589793/4); +		vec2 u = vec2(cos(angle), sin(angle)); 
> + +		// Reject points whose 2D coordinate, projected onto +		//
> that unit vector, is greater than 0.4. +		gl_ClipDistance[i] = 0.4
> - dot(u, coord); +	} }
> 
> [fragment shader] @@ -51,20 +47,26 @@ enable GL_CLIP_PLANE2 enable
> GL_CLIP_PLANE3 enable GL_CLIP_PLANE4 enable GL_CLIP_PLANE5 -draw
> rect 0.1 0.1 0.8 0.8 +enable GL_CLIP_PLANE6 +enable GL_CLIP_PLANE7 
> +draw rect 0.0 0.0 1.0 1.0
> 
> # Test points inside each hexagon edge -relative probe rgba (0.3,
> 0.4) (1.0, 1.0, 1.0, 1.0) -relative probe rgba (0.5, 0.3) (1.0,
> 1.0, 1.0, 1.0) -relative probe rgba (0.7, 0.4) (1.0, 1.0, 1.0,
> 1.0) -relative probe rgba (0.7, 0.6) (1.0, 1.0, 1.0, 1.0) -relative
> probe rgba (0.5, 0.7) (1.0, 1.0, 1.0, 1.0) -relative probe rgba
> (0.3, 0.6) (1.0, 1.0, 1.0, 1.0) +relative probe rgba (0.850, 0.500)
> (1.0, 1.0, 1.0, 1.0) +relative probe rgba (0.747, 0.747) (1.0, 1.0,
> 1.0, 1.0) +relative probe rgba (0.500, 0.850) (1.0, 1.0, 1.0, 1.0) 
> +relative probe rgba (0.253, 0.747) (1.0, 1.0, 1.0, 1.0) +relative
> probe rgba (0.150, 0.500) (1.0, 1.0, 1.0, 1.0) +relative probe rgba
> (0.253, 0.253) (1.0, 1.0, 1.0, 1.0) +relative probe rgba (0.500,
> 0.150) (1.0, 1.0, 1.0, 1.0) +relative probe rgba (0.747, 0.253)
> (1.0, 1.0, 1.0, 1.0)
> 
> # Test points outside each hexagon edge -relative probe rgba (0.2,
> 0.3) (0.0, 0.0, 0.0, 0.0) -relative probe rgba (0.5, 0.2) (0.0,
> 0.0, 0.0, 0.0) -relative probe rgba (0.8, 0.3) (0.0, 0.0, 0.0,
> 0.0) -relative probe rgba (0.8, 0.7) (0.0, 0.0, 0.0, 0.0) -relative
> probe rgba (0.5, 0.8) (0.0, 0.0, 0.0, 0.0) -relative probe rgba
> (0.2, 0.7) (0.0, 0.0, 0.0, 0.0) +relative probe rgba (0.950, 0.500)
> (0.0, 0.0, 0.0, 0.0) +relative probe rgba (0.818, 0.818) (0.0, 0.0,
> 0.0, 0.0) +relative probe rgba (0.500, 0.950) (0.0, 0.0, 0.0, 0.0) 
> +relative probe rgba (0.182, 0.818) (0.0, 0.0, 0.0, 0.0) +relative
> probe rgba (0.050, 0.500) (0.0, 0.0, 0.0, 0.0) +relative probe rgba
> (0.182, 0.182) (0.0, 0.0, 0.0, 0.0) +relative probe rgba (0.500,
> 0.050) (0.0, 0.0, 0.0, 0.0) +relative probe rgba (0.818, 0.182)
> (0.0, 0.0, 0.0, 0.0) diff --git
> a/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-implicitly-sized.shader_test
> b/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-implicitly-sized.shader_test
>
> 
new file mode 100644
> index 0000000..5eee867 --- /dev/null +++
> b/tests/spec/glsl-1.30/execution/clipping/vs-clip-distance-implicitly-sized.shader_test
>
> 
@@ -0,0 +1,67 @@
> +# [description] +# This test verifies that gl_ClipDistance may be
> implicitly +# sized, as specified in section 7.1 (Vertex Shader
> Special Variables) +# of the GLSL 1.30 spec: +# +#   The
> gl_ClipDistance array is predeclared as unsized and must be +#
> sized by the shader either redeclaring it with a size or indexing 
> +#   it only with integral constant expressions. This needs to size
> the +#   array to include all the clip planes that are enabled via
> the +#   OpenGL API; if the size does not include all enabled
> planes, +#   results are undefined. The size can be at most +#
> gl_MaxClipDistances. The number of varying components (see +#
> gl_MaxVaryingComponents) consumed by gl_ClipDistance will match +#
> the size of the array, no matter how many planes are enabled. The 
> +#   shader must also set all values in gl_ClipDistance that have
> been +#   enabled via the OpenGL API, or results are undefined.
> Values +#   written into gl_ClipDistance for planes that are not
> enabled have +#   no effect. +# +# It does so by using 8 clip
> distances to progressively reject points +# with x coordinate less
> than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and +# 0.8.  (The end
> result of this should be to clip all values with x +# coordinate
> less than 0.8).  It then verifies proper clipping +# behavior by
> probing points with x coordinates 0.75 and 0.85. + +[require] +GLSL
> >= 1.30 + +[vertex shader] +#version 130 + +void main() +{ +
> gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; + +
> gl_ClipDistance[0] = gl_Vertex.x - 0.1; +	gl_ClipDistance[1] =
> gl_Vertex.x - 0.2; +	gl_ClipDistance[2] = gl_Vertex.x - 0.3; +
> gl_ClipDistance[3] = gl_Vertex.x - 0.4; +	gl_ClipDistance[4] =
> gl_Vertex.x - 0.5; +	gl_ClipDistance[5] = gl_Vertex.x - 0.6; +
> gl_ClipDistance[6] = gl_Vertex.x - 0.7; +	gl_ClipDistance[7] =
> gl_Vertex.x - 0.8; +} + +[fragment shader] +#version 130 + +void
> main() +{ +	gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0); +} + +[test] 
> +ortho 0 1 0 1 +enable GL_CLIP_PLANE0 +enable GL_CLIP_PLANE1 
> +enable GL_CLIP_PLANE2 +enable GL_CLIP_PLANE3 +enable
> GL_CLIP_PLANE4 +enable GL_CLIP_PLANE5 +enable GL_CLIP_PLANE6 
> +enable GL_CLIP_PLANE7 +draw rect 0.0 0.0 1.0 1.0 + +relative probe
> rgba (0.75, 0.5) (0.0, 0.0, 0.0, 0.0) +relative probe rgba (0.85,
> 0.5) (1.0, 1.0, 1.0, 1.0) diff --git a/tests/util/glew.h
> b/tests/util/glew.h index aec7ede..df4b90f 100644 ---
> a/tests/util/glew.h +++ b/tests/util/glew.h @@ -722,6 +722,8 @@
> typedef char GLchar; #define GL_CLIP_PLANE3 0x3003 #define
> GL_CLIP_PLANE4 0x3004 #define GL_CLIP_PLANE5 0x3005 +#define
> GL_CLIP_PLANE6 0x3006 +#define GL_CLIP_PLANE7 0x3007 #define
> GL_LIGHT0 0x4000 #define GL_COLOR_BUFFER_BIT 0x00004000 #define
> GL_LIGHT1 0x4001
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