[Piglit] [PATCH] Test that nothing is drawn if GS emits too few vertices to create a primitive

Paul Berry stereotype441 at gmail.com
Tue Sep 3 08:37:35 PDT 2013


On 29 August 2013 11:56, Nicholas Mack <nichmack at gmail.com> wrote:

> ---
>  tests/all.tests                               |   1 +
>  tests/spec/glsl-1.50/CMakeLists.gl.txt        |  13 +++
>  tests/spec/glsl-1.50/CMakeLists.txt           |   1 +
>  tests/spec/glsl-1.50/gs-emits-too-few-verts.c | 153
> ++++++++++++++++++++++++++
>  4 files changed, 168 insertions(+)
>  create mode 100644 tests/spec/glsl-1.50/CMakeLists.gl.txt
>  create mode 100644 tests/spec/glsl-1.50/gs-emits-too-few-verts.c
>
> diff --git a/tests/all.tests b/tests/all.tests
> index 7ab841e..efea193 100644
> --- a/tests/all.tests
> +++ b/tests/all.tests
> @@ -937,6 +937,7 @@ for draw in ['', 'indexed']:
>          add_concurrent_test(spec['glsl-1.50'],
>
>  ('arb_geometry_shader4-ignore-adjacent-vertices '
>                               'core {0} {1}').format(draw, prim))
> +spec['glsl-1.50']['gs-emits-too-few-verts'] =
> concurrent_test('gs-emits-too-few-verts')
>
>  # max_vertices of 32 and 128 are important transition points for
>  # mesa/i965 (they are the number of bits in a float and a vec4,
> diff --git a/tests/spec/glsl-1.50/CMakeLists.gl.txt
> b/tests/spec/glsl-1.50/CMakeLists.gl.txt
> new file mode 100644
> index 0000000..7609b98
> --- /dev/null
> +++ b/tests/spec/glsl-1.50/CMakeLists.gl.txt
> @@ -0,0 +1,13 @@
> +include_directories(
> +       ${GLEXT_INCLUDE_DIR}
> +       ${OPENGL_INCLUDE_PATH}
> +)
> +
> +link_libraries (
> +       piglitutil_${piglit_target_api}
> +       ${OPENGL_gl_LIBRARY}
> +       ${OPENGL_glu_LIBRARY}
> +)
> +
> +piglit_add_executable (gs-emits-too-few-verts gs-emits-too-few-verts.c)
> +# vim: ft=cmake:
> diff --git a/tests/spec/glsl-1.50/CMakeLists.txt
> b/tests/spec/glsl-1.50/CMakeLists.txt
> index bb76f08..e4126fc 100644
> --- a/tests/spec/glsl-1.50/CMakeLists.txt
> +++ b/tests/spec/glsl-1.50/CMakeLists.txt
> @@ -1 +1,2 @@
>  add_subdirectory (execution)
> +piglit_include_target_api()
> diff --git a/tests/spec/glsl-1.50/gs-emits-too-few-verts.c
> b/tests/spec/glsl-1.50/gs-emits-too-few-verts.c
> new file mode 100644
> index 0000000..411e697
> --- /dev/null
> +++ b/tests/spec/glsl-1.50/gs-emits-too-few-verts.c
> @@ -0,0 +1,153 @@
> +/**
> + * Copyright © 2013 Intel Corporation
> + *
> + * 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.
> + */
> +
> +/**
> + * From the GLSL 3.2 spec, section 2.12.2 (Geometry Shader Output
> Primitives):
> + *
> + * "If the number of vertices emitted by the geometry shader is not
> sufficient
> + *  to produce a single primitive, nothing is drawn."
> + */
> +
> +#include "piglit-util-gl-common.h"
> +
> +PIGLIT_GL_TEST_CONFIG_BEGIN
> +
> +       config.supports_gl_compat_version = 32;
> +        config.supports_gl_core_version = 32;
> +
> +       config.window_visual = PIGLIT_GL_VISUAL_RGB |
> PIGLIT_GL_VISUAL_DOUBLE;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +static const char *vstext =
> +       "#version 150\n"
> +       "in vec3 vertex;\n"
> +       "out vec3 pos;\n"
> +       "void main() {\n"
> +       "       gl_Position = vec4(vertex, 1.);\n"
> +       "       pos = vertex;\n"
> +       "}\n";
> +
> +static const char *gstext =
> +       "#version 150\n"
> +       "layout(triangles) in;\n"
> +       "layout(triangles, max_vertices = 3) out;\n"
> +       "in vec3 pos[];\n"
> +       "void main() {\n"
> +       "       for(int i = 0; i < pos.length()-1; i++) {\n"
>

Since this test isn't trying to validate that pos.length() behaves
correctly, I would just replace "pos.length()-1" with "2".  That'll make it
more obvious what the test is trying to do.


> +       "               gl_Position = vec4(pos[i], 1.);\n"
> +       "               EmitVertex();\n"
> +       "       }\n"
> +       "}\n";
> +
> +static const char *fstext =
> +       "#version 150\n"
> +       "out vec4 color;\n"
> +       "void main() {\n"
> +       "       color = vec4(1., 0., 0., 1.);\n"
> +       "}\n";
> +
> +static GLuint vao;
> +static GLuint vertBuff;
> +static GLuint indexBuf;
> +
> +static GLfloat vertices[] = {
> +       -1.0, 1.0, 0.0,
> +        1.0, 1.0, 0.0,
> +        1.0,-1.0, 0.0,
> +       -1.0,-1.0, 0.0
> +};
> +static GLsizei vertSize = sizeof(vertices);
> +
> +static GLuint indices[] = {
> +       0, 1, 2, 0, 2, 3
> +};
> +static GLsizei indSize = sizeof(indices);
> +
> +static GLuint prog;
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +       GLuint vs = 0, gs = 0, fs = 0;
> +       GLuint vertIndex;
> +
> +       prog = glCreateProgram();
> +       vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vstext);
> +       gs = piglit_compile_shader_text(GL_GEOMETRY_SHADER, gstext);
> +       fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fstext);
> +       glAttachShader(prog, vs);
> +       glAttachShader(prog, gs);
> +       glAttachShader(prog, fs);
> +
> +       glLinkProgram(prog);
> +       if(!piglit_link_check_status(prog)){
> +               glDeleteProgram(prog);
> +               piglit_report_result(PIGLIT_FAIL);
> +       }
> +
> +       glUseProgram(prog);
> +
> +       glGenBuffers(1, &vertBuff);
> +       glBindBuffer(GL_ARRAY_BUFFER, vertBuff);
> +       glBufferData(GL_ARRAY_BUFFER, vertSize, vertices, GL_STATIC_DRAW);
> +
> +       glGenBuffers(1, &indexBuf);
> +       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuf);
> +       glBufferData(GL_ELEMENT_ARRAY_BUFFER, indSize,
> +                       indices, GL_STATIC_DRAW);
> +
> +       glGenVertexArrays(1, &vao);
> +       glBindVertexArray(vao);
> +
> +       vertIndex = glGetAttribLocation(prog, "vertex");
> +
> +       glBindBuffer(GL_ARRAY_BUFFER, vertBuff);
> +       glEnableVertexAttribArray(vertIndex);
> +       glVertexAttribPointer(vertIndex, 3, GL_FLOAT, GL_FALSE, 0, 0);
> +}
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +       bool pass = true;
> +       float grey[] = {.4, .4, .4};
> +
> +       glClearColor(.4, .4, .4, 1.);
> +       glClear(GL_COLOR_BUFFER_BIT);
> +
> +       glBindVertexArray(vao);
> +       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuf);
> +
> +       glDrawElements(GL_TRIANGLES, ARRAY_SIZE(indices),
> +                       GL_UNSIGNED_INT, NULL);
> +       pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
> +
> +       /* Geom shader only emits 2 verts per tri, so it should not draw
> any */
> +       pass = piglit_probe_rect_rgb(0, 0, piglit_width, piglit_height,
> grey)
> +               && pass;
>

I'd propose an additional check: surround the draw call with a query of
GL_PRIMITIVES_GENERATED, and make sure the query returns a value of 0.
That way we can have confidence that the implementation didn't try to do
something silly like a draw a degenerate triangle.

+
> +       piglit_present_results();
> +
> +       return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
> --
> 1.8.3.1
>
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