[Piglit] [PATCH 1/1] Add a small test for gl_Fog.scale when fog start and end are equal.

[Ian Romanick]

With the couple minor nits below fixed,

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

On 08/24/2013 02:23 PM, Henri Verbeet wrote:
> Signed-off-by: Henri Verbeet <hverbeet at gmail.com>
> ---
>  tests/all.tests                  |    1 +
>  tests/shaders/CMakeLists.gl.txt  |    1 +
>  tests/shaders/glsl-fs-fogscale.c |   86 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 88 insertions(+)
>  create mode 100644 tests/shaders/glsl-fs-fogscale.c
> 
> diff --git a/tests/all.tests b/tests/all.tests
> index 128de58..e395865 100644
> --- a/tests/all.tests
> +++ b/tests/all.tests
> @@ -261,6 +261,7 @@ add_plain_test(shaders, 'glsl-fs-discard-02')
>  add_plain_test(shaders, 'glsl-fs-exp2')
>  add_plain_test(shaders, 'glsl-fs-flat-color')
>  add_plain_test(shaders, 'glsl-fs-fogcolor-statechange')
> +add_plain_test(shaders, 'glsl-fs-fogscale')
>  add_plain_test(shaders, 'glsl-fs-fragcoord')
>  add_plain_test(shaders, 'glsl-fs-fragcoord-zw-ortho')
>  add_plain_test(shaders, 'glsl-fs-fragcoord-zw-perspective')
> diff --git a/tests/shaders/CMakeLists.gl.txt b/tests/shaders/CMakeLists.gl.txt
> index 5de5b95..ccd228a 100644
> --- a/tests/shaders/CMakeLists.gl.txt
> +++ b/tests/shaders/CMakeLists.gl.txt
> @@ -72,6 +72,7 @@ piglit_add_executable (glsl-fs-color-matrix glsl-fs-color-matrix.c)
>  piglit_add_executable (glsl-fs-exp2 glsl-fs-exp2.c)
>  piglit_add_executable (glsl-fs-flat-color glsl-fs-flat-color.c)
>  piglit_add_executable (glsl-fs-fogcolor-statechange glsl-fs-fogcolor-statechange.c)
> +piglit_add_executable (glsl-fs-fogscale glsl-fs-fogscale.c)
>  piglit_add_executable (glsl-fs-fragcoord glsl-fs-fragcoord.c)
>  piglit_add_executable (glsl-fs-fragcoord-zw-ortho glsl-fs-fragcoord-zw-ortho.c)
>  piglit_add_executable (glsl-fs-fragcoord-zw-perspective glsl-fs-fragcoord-zw-perspective.c)
> diff --git a/tests/shaders/glsl-fs-fogscale.c b/tests/shaders/glsl-fs-fogscale.c
> new file mode 100644
> index 0000000..cb4bdf5
> --- /dev/null
> +++ b/tests/shaders/glsl-fs-fogscale.c
> @@ -0,0 +1,86 @@
> +/*
> + * Copyright © 2013 Henri Verbeet <hverbeet at gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +/** @file glsl-fs-fogscale.c
> + *
> + * Tests that gl_Fog.scale is equivalent to
> + * "1.0 / (gl_Fog.end - gl_Fog.start)" when fog start and end are equal.

I'd beef this comment up with something to the effect, "The expectation
is that 1/0 will produce a value similar to +INF.  This takes into
account that GPUs may not have a representation for INF."

> + */
> +
> +#include "piglit-util-gl-common.h"
> +
> +PIGLIT_GL_TEST_CONFIG_BEGIN
> +
> +	config.supports_gl_compat_version = 10;

Make this 20 and delete the piglit_require_gl_version below.

> +
> +	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +	static const float green[] = {0.0f, 1.0f, 0.0f, 1.0f};
> +	static const float red[] = {1.0f, 0.0f, 0.0f, 1.0f};
> +	GLboolean pass = GL_TRUE;

bool

> +
> +	glClearColor(0.0, 0.0, 1.0, 0.0);
> +	glClear(GL_COLOR_BUFFER_BIT);
> +
> +	piglit_draw_rect(-1, -1, 2, 2);
> +	pass &= piglit_probe_rect_rgba(0, 0,
> +				       piglit_width / 2, piglit_height,
> +				       green);

You should use

    pass = foo() && pass;

because of the C short-circuit evaluation rules.

> +	pass &= piglit_probe_rect_rgba(piglit_width / 2, 0,
> +				       piglit_width / 2, piglit_height,
> +				       red);
> +
> +	piglit_present_results();
> +
> +	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +	static const char vs_source[] =
> +		"void main()\n"
> +		"{\n"
> +		"	gl_Position = gl_Vertex;\n"
> +		"	gl_FogFragCoord = gl_Position.x;\n"
> +		"}\n";
> +	static const char fs_source[] =
> +		"void main()\n"
> +		"{\n"
> +		"	gl_FragColor = vec4(gl_FogFragCoord * gl_Fog.scale * vec2(1.0, -1.0), 0.0, 1.0);\n"
> +		"}\n";
> +	GLuint prog;
> +
> +	piglit_require_gl_version(20);
> +
> +	prog = piglit_build_simple_program(vs_source, fs_source);
> +
> +	glFogf(GL_FOG_START, 0.0f);
> +	glFogf(GL_FOG_END, 0.0f);
> +	glUseProgram(prog);
> +}
>