[Piglit] [PATCH] Test that fragment shader writes to render targets are properly ordered.
Paul Berry
stereotype441 at gmail.com
Tue Jul 24 15:14:00 PDT 2012
Some hardware platforms (e.g. i965 gen6+) are capable of processing
the fragments corresponding to multiple primitives in parallel, even
if those primitives overlap on the screen. This test verifies that in
such situations, the fragment shader outputs are written to the
framebuffer in the correct order.
---
tests/spec/glsl-1.30/execution/CMakeLists.gl.txt | 1 +
.../glsl-1.30/execution/fs-execution-ordering.c | 178 ++++++++++++++++++++
2 files changed, 179 insertions(+), 0 deletions(-)
create mode 100644 tests/spec/glsl-1.30/execution/fs-execution-ordering.c
diff --git a/tests/spec/glsl-1.30/execution/CMakeLists.gl.txt b/tests/spec/glsl-1.30/execution/CMakeLists.gl.txt
index a582c3f..6737bb1 100644
--- a/tests/spec/glsl-1.30/execution/CMakeLists.gl.txt
+++ b/tests/spec/glsl-1.30/execution/CMakeLists.gl.txt
@@ -19,3 +19,4 @@ ENDIF (NOT MSVC)
piglit_add_executable (vertexid-beginend vertexid-beginend.c)
piglit_add_executable (vertexid-drawarrays vertexid-drawarrays.c)
piglit_add_executable (vertexid-drawelements vertexid-drawelements.c)
+piglit_add_executable (fs-execution-ordering fs-execution-ordering.c)
diff --git a/tests/spec/glsl-1.30/execution/fs-execution-ordering.c b/tests/spec/glsl-1.30/execution/fs-execution-ordering.c
new file mode 100644
index 0000000..ccb0b77
--- /dev/null
+++ b/tests/spec/glsl-1.30/execution/fs-execution-ordering.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright © 2012 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.
+ */
+
+/**
+ * fs-execution-ordering.c
+ *
+ * Confirm that fragment shader outputs are written to the color
+ * buffer in the correct order, even if some fragments take
+ * dramatically longer to execute than others.
+ *
+ * Since this test is looking for race conditions, it repeats 100
+ * times, drawing different primitives sizes, to increase the chances
+ * of a race condition occurring.
+ */
+
+#include "piglit-util-gl-common.h"
+
+#define SHIFT_COUNT 64
+
+PIGLIT_GL_TEST_MAIN(
+ 100 /* window_width */,
+ 100 /* window_height */,
+ GLUT_DOUBLE | GLUT_RGB | GLUT_ALPHA)
+
+#define SMALL_COMPOSITE 4
+#define LARGE_PRIME 7919
+
+GLint prog;
+GLuint vbo_handle;
+
+static const char *vstext =
+ "#version 130\n"
+ "in uint num;\n"
+ "in vec4 pos;\n"
+ "flat out uint number_to_classify;\n"
+ "\n"
+ "void main()\n"
+ "{\n"
+ " gl_Position = pos;\n"
+ " number_to_classify = num;\n"
+ "}\n";
+
+/* This fragment shader implements a simple primality test using trial
+ * division. It outputs a color of red if its input is prime, and
+ * green if its input is composite.
+ *
+ * Note: no special effort has been made to use a very fast algorithm,
+ * since the purpose of the shader is to have dramatically different
+ * execution times based on the input parameter.
+ */
+static const char *fstext =
+ "#version 130\n"
+ "flat in uint number_to_classify;\n"
+ "\n"
+ "void main()\n"
+ "{\n"
+ " bool factor_found = false;\n"
+ " for (uint i = 2u; i < number_to_classify; ++i) {\n"
+ " if (number_to_classify % i == 0u)\n"
+ " factor_found = true;\n"
+ " }\n"
+ " gl_FragColor = factor_found ?\n"
+ " vec4(0.0, 1.0, 0.0, 1.0) :\n"
+ " vec4(1.0, 0.0, 0.0, 1.0);\n"
+ "}\n";
+
+void
+piglit_init(int argc, char **argv)
+{
+ GLuint vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vstext);
+ GLuint fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fstext);
+ prog = piglit_link_simple_program(vs, fs);
+ glGenBuffers(1, &vbo_handle);
+
+ if (!piglit_check_gl_error(GL_NO_ERROR))
+ piglit_report_result(PIGLIT_FAIL);
+}
+
+bool
+do_test(unsigned size)
+{
+ float expected_color[4] = { 0.0, 1.0, 0.0, 1.0 };
+
+ /* Set up the necessary vertex array to draw two squares, each
+ * size x size pixels. The first square is drawn using a
+ * large prime number for the "num" parameter, so it will be
+ * drawn in red and take a long time to compute. The second
+ * square is drawn using a small composite number for the
+ * "num" parameter, so it will be drawn in green and take a
+ * short time to compute.
+ *
+ * Even though the second square takes a short time to
+ * compute, it should be written to the color buffer after the
+ * first square, so the result should be a green square.
+ */
+ GLfloat xmin = -1.0;
+ GLfloat ymin = -1.0;
+ GLfloat xmax = 2.0 * size / piglit_width - 1.0;
+ GLfloat ymax = 2.0 * size / piglit_height - 1.0;
+ struct vertex_attributes {
+ GLfloat pos[2];
+ GLuint num;
+ } vertex_data[] = {
+ { { xmin, ymin }, LARGE_PRIME },
+ { { xmin, ymax }, LARGE_PRIME },
+ { { xmax, ymax }, LARGE_PRIME },
+ { { xmin, ymin }, LARGE_PRIME },
+ { { xmax, ymax }, LARGE_PRIME },
+ { { xmax, ymin }, LARGE_PRIME },
+ { { xmin, ymin }, SMALL_COMPOSITE },
+ { { xmax, ymax }, SMALL_COMPOSITE },
+ { { xmax, ymin }, SMALL_COMPOSITE },
+ { { xmin, ymin }, SMALL_COMPOSITE },
+ { { xmin, ymax }, SMALL_COMPOSITE },
+ { { xmax, ymax }, SMALL_COMPOSITE },
+ };
+
+ size_t stride = sizeof(vertex_data[0]);
+ GLint pos_index = glGetAttribLocation(prog, "pos");
+ GLint num_index = glGetAttribLocation(prog, "num");
+ glBindBuffer(GL_ARRAY_BUFFER, vbo_handle);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), &vertex_data,
+ GL_STATIC_DRAW);
+ glVertexAttribPointer(pos_index, 2, GL_FLOAT, GL_FALSE, stride,
+ (void *) offsetof(struct vertex_attributes,
+ pos));
+ glVertexAttribIPointer(num_index, 1, GL_UNSIGNED_INT, stride,
+ (void *) offsetof(struct vertex_attributes,
+ num));
+ glEnableVertexAttribArray(pos_index);
+ glEnableVertexAttribArray(num_index);
+
+ /* Draw the squares and check their color. */
+ glDrawArrays(GL_TRIANGLES, 0, ARRAY_SIZE(vertex_data));
+ return piglit_probe_rect_rgba(0, 0, size, size, expected_color);
+}
+
+enum piglit_result
+piglit_display(void)
+{
+ enum piglit_result result = PIGLIT_PASS;
+ unsigned size;
+
+ glUseProgram(prog);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ for (size = 1; size <= 100; ++size) {
+ if (!do_test(size)) {
+ printf("Failed at rect size %dx%d\n", size, size);
+ result = PIGLIT_FAIL;
+ break;
+ }
+ }
+
+ piglit_present_results();
+
+ return result;
+}
--
1.7.7.6
More information about the Piglit
mailing list