[Piglit] [PATCH] gs: Test EndPrimitive() functionality.

Kenneth Graunke kenneth at whitecape.org
Fri Aug 23 12:17:44 PDT 2013


On 08/11/2013 10:32 PM, Paul Berry wrote:
> ---
>   tests/all.tests                                    |   9 +
>   tests/spec/glsl-1.50/execution/CMakeLists.txt      |   1 +
>   .../glsl-1.50/execution/geometry/CMakeLists.gl.txt |  13 +
>   .../glsl-1.50/execution/geometry/CMakeLists.txt    |   1 +
>   .../glsl-1.50/execution/geometry/end-primitive.c   | 393 +++++++++++++++++++++
>   5 files changed, 417 insertions(+)
>   create mode 100644 tests/spec/glsl-1.50/execution/geometry/CMakeLists.gl.txt
>   create mode 100644 tests/spec/glsl-1.50/execution/geometry/CMakeLists.txt
>   create mode 100644 tests/spec/glsl-1.50/execution/geometry/end-primitive.c
>
> diff --git a/tests/all.tests b/tests/all.tests
> index a914a2a..bebb69a 100644
> --- a/tests/all.tests
> +++ b/tests/all.tests
> @@ -910,6 +910,15 @@ for draw in ['', 'indexed']:
>                               ('arb_geometry_shader4-ignore-adjacent-vertices '
>                                'core {0} {1}').format(draw, prim))
>
> +# 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,
> +# respectively), so test around there.  Also test 0, which means the
> +# maximum number of geometry shader output vertices supported by the
> +# hardware.
> +for i in [31, 32, 33, 34, 127, 128, 129, 130, 0]:
> +    add_concurrent_test(spec['glsl-1.50'],
> +                        'glsl-1.50-geometry-end-primitive {0}'.format(i))
> +
>   # Group spec/glsl-es-3.00
>   spec['glsl-es-3.00'] = Group()
>   import_glsl_parser_tests(spec['glsl-es-3.00'],
> diff --git a/tests/spec/glsl-1.50/execution/CMakeLists.txt b/tests/spec/glsl-1.50/execution/CMakeLists.txt
> index 144a306..c0c4f05 100644
> --- a/tests/spec/glsl-1.50/execution/CMakeLists.txt
> +++ b/tests/spec/glsl-1.50/execution/CMakeLists.txt
> @@ -1 +1,2 @@
>   piglit_include_target_api()
> +add_subdirectory (geometry)
> diff --git a/tests/spec/glsl-1.50/execution/geometry/CMakeLists.gl.txt b/tests/spec/glsl-1.50/execution/geometry/CMakeLists.gl.txt
> new file mode 100644
> index 0000000..d4becb7
> --- /dev/null
> +++ b/tests/spec/glsl-1.50/execution/geometry/CMakeLists.gl.txt
> @@ -0,0 +1,13 @@
> +include_directories(
> +${GLEXT_INCLUDE_DIR}
> +${OPENGL_INCLUDE_PATH}
> +${piglit_SOURCE_DIR}/tests/util
> +)
> +
> +link_libraries (
> +piglitutil_${piglit_target_api}
> +${OPENGL_gl_LIBRARY}
> +${OPENGL_glu_LIBRARY}
> +)
> +
> +piglit_add_executable (glsl-1.50-geometry-end-primitive end-primitive.c)
> diff --git a/tests/spec/glsl-1.50/execution/geometry/CMakeLists.txt b/tests/spec/glsl-1.50/execution/geometry/CMakeLists.txt
> new file mode 100644
> index 0000000..144a306
> --- /dev/null
> +++ b/tests/spec/glsl-1.50/execution/geometry/CMakeLists.txt
> @@ -0,0 +1 @@
> +piglit_include_target_api()
> diff --git a/tests/spec/glsl-1.50/execution/geometry/end-primitive.c b/tests/spec/glsl-1.50/execution/geometry/end-primitive.c
> new file mode 100644
> index 0000000..9400229
> --- /dev/null
> +++ b/tests/spec/glsl-1.50/execution/geometry/end-primitive.c
> @@ -0,0 +1,393 @@
> +/*
> + * 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.
> + */
> +
> +/**
> + * \file end-primitive.c
> + *
> + * Verify functionality of the geometry shader EndPrimitive() function.
> + *
> + * This test checks that EndPrimitive() works properly for the
> + * combination of output primitive type and max vertex count speficied
> + * on the command line.
> + *
> + * The test operates by sending three POINT primitives down the
> + * pipeline.  The geometry shader converts each POINT primitive into a
> + * triangle_strip containing the requested number of vertices.
> + * EndPrimitive() is called after every third vertex, so the resulting
> + * image consists of discrete triangles.  The triangles are arranged
> + * into a spiral pattern so that the maximum geometry shader output
> + * vertex count can be accommodated without making the triangles too
> + * small.
> + *
> + * Each of the 3 geometry shader invocations calls EndPrimitive() at
> + * different times (the first invocation calls it prior to vertices 0,
> + * 3, 6, 9, etc., the second invocation prior to vertices 1, 4, 7, 10,
> + * etc., and the third invocation prior to vertices 2, 5, 8, 11,
> + * etc.).  The colors of the triangles are red for the first geometry
> + * shader invocation, green for the second, and blue for the third.
> + * So the resulting image should show the entire triangle strip with
> + * colors sequencing in red, green, blue order.
> + *
> + * Colors are communicated from the geometry shader to the fragment
> + * shader by adjusting the value of gl_Position.z.  This allows us to
> + * avoid taking up an extra varying slot to communicate color (which
> + * might reduce the number of vertices we can test, due to
> + * GL_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS).
> + *
> + * The test image is drawn twice, once in the manner described above
> + * (the test pattern), and once without using geometry shaders (the
> + * reference pattern).  The test and reference pattern are then
> + * compared.

Brilliant.  I like it.

> + * The image is drawn with a blend equation of GL_MAX, so that if any
> + * call to EndPrimitive() fails to work, the result will be visible,
> + * even if a subsequent geometry shader invocation draws over the same
> + * part of the image.
> + */
> +
> +
> +#include "piglit-util-gl-common.h"
> +
> +#define PATTERN_SIZE 256
> +
> +PIGLIT_GL_TEST_CONFIG_BEGIN
> +
> +	config.supports_gl_compat_version = 32;
> +	config.supports_gl_core_version = 32;
> +	config.window_width = 2*PATTERN_SIZE;
> +	config.window_height = PATTERN_SIZE;
> +	config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +static GLuint prog_ref, prog_test, fb;
> +static int num_vertices;
> +
> +/**
> + * Function to compute the spiral pattern.  The distance between
> + * adjacent vertices returned by this function is approximately
> + * constant, so the resulting triangles will be approximately equal in
> + * size.
> + */
> +static const char *spiral_text =
> +	"#version 150\n"
> +	"\n"
> +	"uniform int num_vertices;\n"
> +	"\n"
> +	"vec2 spiral(int vertex_id)\n"
> +	"{\n"
> +	"  float pi = acos(-1.0);\n"
> +	"  float radial_spacing = 1.5;\n"
> +	"  float spiral_spacing = 0.5;\n"
> +	"  float a = 4.0*pi*spiral_spacing/radial_spacing;\n"
> +	"  float b = radial_spacing/(2*pi);\n"
> +	"  float theta = sqrt(a*float(vertex_id + 1));\n"
> +	"  float r = b*theta;\n"
> +	"  if (vertex_id % 2 == 1) r += 1.0;\n"
> +	"  float max_r = b*sqrt(a*float(num_vertices)) + 1.0;\n"
> +	"  r /= max_r;\n"
> +	"  return r*vec2(cos(theta), sin(theta));\n"
> +	"}\n";

I didn't review this code, but I trust that it works.

> +/**
> + * Vertex shader for drawing the test pattern.  The incoming vertex ID
> + * is passed down into the geometry shader, so that it can tell which
> + * invocation it is.
> + */
> +static const char *vs_test_text =
> +	"#version 150\n"
> +	"\n"
> +	"out int end_prim_offset;\n"
> +	"\n"
> +	"void main()\n"
> +	"{\n"
> +	"  end_prim_offset = gl_VertexID;\n"
> +	"}\n";
> +
> +/**
> + * Geometry shader for drawing the test pattern.
> + */
> +static const char *gs_test_text =
> +	"#version 150\n"
> +	"\n"
> +	"vec2 spiral(int vertex_id);\n"
> +	"uniform int num_vertices;\n"
> +	"in int end_prim_offset[];\n"
> +	"\n"
> +	"void main()\n"
> +	"{\n"
> +	"  int i = 0;\n"
> +	"  while (true) {\n"
> +	"    if (i % 3 == end_prim_offset[0])\n"
> +	"      EndPrimitive();\n"
> +	"    if (i == num_vertices)\n"
> +	"      break;\n"
> +	"    gl_Position = vec4(spiral(i++), end_prim_offset[0]/4.0, 1.0);\n"
> +	"    EmitVertex();\n"
> +	"  }\n"
> +	"}\n";
> +
> +/**
> + * Printf template for the geometry shader layout.  %d will be filled
> + * in with the number of vertices requested on the command line.
> + */
> +static const char *gs_layout_template =
> +	"#version 150\n"
> +	"\n"
> +	"layout(points) in;\n"
> +	"layout(triangle_strip, max_vertices = %d) out;\n";
> +
> +/**
> + * Fragment shader for drawing both the test and reference patterns.
> + */
> +static const char *fs_text =
> +	"#version 150\n"
> +	"\n"
> +	"void main()\n"
> +	"{\n"
> +	"  int end_prim_offset = int(round((gl_FragCoord.z - 0.5) * 8.0));\n"
> +	"  const vec4 colors[3] = vec4[3](\n"
> +	"    vec4(1.0, 0.0, 0.0, 1.0),\n"
> +	"    vec4(0.0, 1.0, 0.0, 1.0),\n"
> +	"    vec4(0.0, 0.0, 1.0, 1.0));\n"
> +	"  gl_FragColor = colors[end_prim_offset];\n"
> +	"}\n";
> +
> +/**
> + * Vertex shader for drawing the reference pattern.  gl_VertexID takes
> + * the place of the variable i in the geometry shader.
> + */
> +static const char *vs_ref_text =
> +	"#version 150\n"
> +	"\n"
> +	"vec2 spiral(int vertex_id);\n"
> +	"uniform int end_prim_offset;\n"
> +	"\n"
> +	"void main()\n"
> +	"{\n"
> +	"  gl_Position = vec4(spiral(gl_VertexID), end_prim_offset/4.0,\n"
> +	"                     1.0);\n"
> +	"}\n";
> +
> +
> +static void
> +print_usage_and_exit(const char *prog_name)
> +{
> +	printf("Usage: %s <vertex_count>\n"
> +	       "  where <vertex_count> is the number of vertices to test, or\n"
> +	       "  0 to test the maximum possible number of vertices.\n",
> +	       prog_name);
> +	piglit_report_result(PIGLIT_FAIL);
> +}
> +
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +	GLuint vs_spiral, gs_spiral, vs_ref_main, vs_test_main, gs_test_main,
> +		gs_layout, fs_main, vao, element_buf, rb;
> +	GLint max_gs_out_vertices, max_gs_out_components;
> +	int max_testable_vertices;
> +	char *text, *endptr;
> +
> +	/* parse args */
> +	if (argc != 2)
> +		print_usage_and_exit(argv[0]);
> +	endptr = NULL;
> +	num_vertices = strtol(argv[1], &endptr, 0);
> +	if (endptr != argv[1] + strlen(argv[1]))
> +		print_usage_and_exit(argv[0]);
> +
> +	/* Figure out the maximum number of vertices we can test. */
> +	glGetIntegerv(GL_MAX_GEOMETRY_OUTPUT_VERTICES, &max_gs_out_vertices);
> +	glGetIntegerv(GL_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS,
> +		      &max_gs_out_components);
> +	if (!piglit_check_gl_error(GL_NO_ERROR))
> +		piglit_report_result(PIGLIT_FAIL);
> +	max_testable_vertices = MIN2(max_gs_out_vertices,
> +				     max_gs_out_components / 4);
> +
> +	/* If num_vertices == 0, test the maximum possible number of
> +	 * vertices.  Otherwise ensure that the requested number is
> +	 * supported by the implementation.
> +	 */
> +	if (num_vertices == 0)
> +		num_vertices = max_testable_vertices;
> +	else if (num_vertices > max_testable_vertices) {
> +		printf("Can't test more than %d vertices\n",
> +		       max_testable_vertices);
> +		piglit_report_result(PIGLIT_SKIP);
> +	}
> +
> +	/* Compile shaders */
> +	vs_spiral = piglit_compile_shader_text(GL_VERTEX_SHADER, spiral_text);
> +	gs_spiral = piglit_compile_shader_text(GL_GEOMETRY_SHADER,
> +					       spiral_text);
> +	vs_ref_main = piglit_compile_shader_text(GL_VERTEX_SHADER,
> +						 vs_ref_text);
> +	vs_test_main = piglit_compile_shader_text(GL_VERTEX_SHADER,
> +						  vs_test_text);
> +	gs_test_main = piglit_compile_shader_text(GL_GEOMETRY_SHADER,
> +						  gs_test_text);
> +	asprintf(&text, gs_layout_template, num_vertices);
> +	gs_layout = piglit_compile_shader_text(GL_GEOMETRY_SHADER, text);
> +	free(text);
> +	fs_main = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fs_text);
> +
> +	prog_ref = glCreateProgram();
> +	glAttachShader(prog_ref, vs_ref_main);
> +	glAttachShader(prog_ref, vs_spiral);
> +	glAttachShader(prog_ref, fs_main);
> +	glLinkProgram(prog_ref);
> +	if (!piglit_link_check_status(prog_ref))
> +		piglit_report_result(PIGLIT_FAIL);
> +
> +	prog_test = glCreateProgram();
> +	glAttachShader(prog_test, vs_test_main);
> +	glAttachShader(prog_test, gs_test_main);
> +	glAttachShader(prog_test, gs_spiral);
> +	glAttachShader(prog_test, gs_layout);
> +	glAttachShader(prog_test, fs_main);
> +	glLinkProgram(prog_test);
> +	if (!piglit_link_check_status(prog_test))
> +		piglit_report_result(PIGLIT_FAIL);
> +
> +	glDeleteShader(vs_spiral);
> +	glDeleteShader(gs_spiral);
> +	glDeleteShader(vs_ref_main);
> +	glDeleteShader(vs_test_main);
> +	glDeleteShader(gs_test_main);
> +	glDeleteShader(gs_layout);
> +	glDeleteShader(fs_main);
> +
> +	/* Various other GL objects needed by the test */
> +	glGenVertexArrays(1, &vao);
> +	glBindVertexArray(vao);
> +	glGenBuffers(1, &element_buf);
> +	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, element_buf);
> +	glGenFramebuffers(1, &fb);
> +	glBindFramebuffer(GL_FRAMEBUFFER, fb);
> +	glGenRenderbuffers(1, &rb);
> +	glBindRenderbuffer(GL_RENDERBUFFER, rb);
> +	glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, PATTERN_SIZE,
> +			      PATTERN_SIZE);
> +	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
> +				  GL_RENDERBUFFER, rb);
> +
> +	if (!piglit_check_gl_error(GL_NO_ERROR))
> +		piglit_report_result(PIGLIT_FAIL);
> +}
> +
> +
> +/**
> + * Simulate the action of the 3 geometry shader invocations by making
> + * 3 glDrawElements() calls.  Primitive restart is used to simulate
> + * the action of EndPrimitive().
> + */
> +static void
> +draw_ref_pattern()
> +{
> +	int i, vertex_count, end_prim_offset;
> +
> +	glClear(GL_COLOR_BUFFER_BIT);
> +	glUseProgram(prog_ref);
> +	glUniform1i(glGetUniformLocation(prog_ref, "num_vertices"),
> +		    num_vertices);
> +	glEnable(GL_PRIMITIVE_RESTART);
> +	glPrimitiveRestartIndex(0xffffffff);
> +
> +	for (end_prim_offset = 0; end_prim_offset < 3; end_prim_offset++) {
> +		GLuint *index_buffer =
> +			malloc(2 * sizeof(GLuint) * num_vertices);

This is overallocating, right?  Your index buffer would normally be [0, 
1, 2, 3, ..] except that you're inserting 0xffffffff every 3 vertices. 
Wouldn't (num_vertices + ceil(num_vertices/3.) ) * sizeof(GLuint) work?

Overallocating shouldn't hurt anything - it's safe and avoids irritating 
rounding problems - but it might be nice to have a comment saying that's 
what you're doing.

> +		i = vertex_count = 0;
> +		while (true) {
> +			if (i % 3 == end_prim_offset)
> +				index_buffer[vertex_count++] = 0xffffffff;
> +			if (i == num_vertices)
> +				break;
> +			index_buffer[vertex_count++] = i++;
> +		}

Wouldn't the following also work?

while (i < num_vertices) {
	if (i % 3 == end_prim_offset)
		index_buffer[vertex_count++] = 0xffffffff;
	index_buffer[vertex_count++] = i++;
}

You might not get the 0xffffffff at the very end, but since it's the end 
of your draw call anyway, I don't think it would matter.

Not a big deal either way.  As is, it matches your shader, and that's 
worth preserving...

> +		glUniform1i(glGetUniformLocation(prog_ref, "end_prim_offset"),
> +			    end_prim_offset);
> +		glBufferData(GL_ELEMENT_ARRAY_BUFFER,
> +			     sizeof(GLuint) * vertex_count, index_buffer,
> +			     GL_STATIC_DRAW);
> +		free(index_buffer);
> +		glDrawElements(GL_TRIANGLE_STRIP, vertex_count,
> +			       GL_UNSIGNED_INT, NULL);
> +	}
> +
> +	glDisable(GL_PRIMITIVE_RESTART);
> +}
> +
> +
> +static void
> +draw_test_pattern()
> +{
> +	glClear(GL_COLOR_BUFFER_BIT);
> +	glUseProgram(prog_test);
> +	glUniform1i(glGetUniformLocation(prog_test, "num_vertices"),
> +		    num_vertices);
> +	glDrawArrays(GL_POINTS, 0, 3);
> +}
> +
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +	bool pass = true;
> +
> +	glEnable(GL_BLEND);
> +	glBlendEquation(GL_MAX);
> +
> +	/* Left half of the window is the test pattern */
> +	glViewport(0, 0, PATTERN_SIZE, PATTERN_SIZE);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb);
> +	draw_test_pattern();
> +	glBindFramebuffer(GL_READ_FRAMEBUFFER, fb);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
> +	glBlitFramebuffer(0, 0, PATTERN_SIZE, PATTERN_SIZE,
> +			  0, 0, PATTERN_SIZE, PATTERN_SIZE,
> +			  GL_COLOR_BUFFER_BIT, GL_NEAREST);
> +
> +	/* Right half of the window is the reference image */
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb);
> +	draw_ref_pattern();
> +	glBindFramebuffer(GL_READ_FRAMEBUFFER, fb);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
> +	glBlitFramebuffer(0, 0, PATTERN_SIZE, PATTERN_SIZE,
> +			  PATTERN_SIZE, 0, 2*PATTERN_SIZE, PATTERN_SIZE,
> +			  GL_COLOR_BUFFER_BIT, GL_NEAREST);

You could probably just adjust the viewport rather than monkeying around 
with multiple framebuffers and blitting.  Should be simpler.

> +	if (!piglit_check_gl_error(GL_NO_ERROR))
> +		pass = false;
> +
> +	/* Compare window halves */
> +	glBindFramebuffer(GL_READ_FRAMEBUFFER, piglit_winsys_fbo);
> +	pass = piglit_probe_rect_halves_equal_rgba(0, 0, 2*PATTERN_SIZE,
> +						   PATTERN_SIZE) && pass;
> +
> +	piglit_present_results();
> +
> +	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
>

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>


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