[Piglit] [PATCH 2/2] ext_framebuffer_multisample: Add a test for alpha to coverage with no draw buffer zero write
Anuj Phogat
anuj.phogat at gmail.com
Wed Nov 2 21:36:20 UTC 2016
In a situation when there are multiple render targets with alpha to
coverage enabled, if fragment shader doesn't write to draw buffer
zero, alpha value used for coverage will be undefined. Such case
should not cause a GPU hang.
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
Not everything in allocate_data_arrays() is useful for this test
case. But additional allocations don't hurt as we're freeing all
of them later in free_data_arrays(). Using these functions is
simply convenient to write multiple draw buffers tests.
---
.../ext_framebuffer_multisample/CMakeLists.gl.txt | 2 +
...alpha-to-coverage-no-draw-buffer-zero-write.cpp | 134 +++++++++++++++++++++
2 files changed, 136 insertions(+)
create mode 100644 tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero-write.cpp
diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index 944a93e..6841267 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -11,6 +11,8 @@ link_libraries (
piglit_add_executable (ext_framebuffer_multisample-accuracy common.cpp accuracy.cpp)
piglit_add_executable (ext_framebuffer_multisample-alpha-to-coverage-no-draw-buffer-zero common.cpp
draw-buffers-common.cpp alpha-to-coverage-no-draw-buffer-zero.cpp)
+piglit_add_executable (ext_framebuffer_multisample-alpha-to-coverage-no-draw-buffer-zero-write common.cpp
+ draw-buffers-common.cpp alpha-to-coverage-no-draw-buffer-zero-write.cpp)
piglit_add_executable (ext_framebuffer_multisample-alpha-to-coverage-dual-src-blend common.cpp
draw-buffers-common.cpp alpha-to-coverage-dual-src-blend.cpp)
piglit_add_executable (ext_framebuffer_multisample-alpha-to-one-dual-src-blend common.cpp
diff --git a/tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero-write.cpp b/tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero-write.cpp
new file mode 100644
index 0000000..a6150bd
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero-write.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright © 2016 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.
+ */
+
+#include "draw-buffers-common.h"
+
+/**
+ * \file alpha-to-coverage-no-draw-buffer-zero-write.cpp
+ *
+ * Verify sample alpha to coverage with multiple draw buffers when nothing
+ * is written to draw buffer zero.
+ *
+ * When nothing is written to draw buffer zero, GL_SAMPLE_ALPHA_TO_COVERAGE
+ * usage shouldn't hang the system. The alpha value used to determine
+ * coverage will be undefined which will result in to pixels with undefined
+ * colors. So, pixels can't be probed for color in this test.
+ *
+ * From OpenGL 2.1 specification:
+ * "If a fragment shader writes to neither gl FragColor nor gl FragData,
+ * the values of the fragment colors following shader execution are
+ * undefined, and may differ for each fragment color."
+ *
+ * It is a significant edge case for i965 driver.
+ */
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+ config.supports_gl_compat_version = 21;
+
+ config.window_width = 512;
+ config.window_height = 768;
+ config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+void
+print_usage_and_exit(char *prog_name)
+{
+ printf("Usage: %s <num_samples>\n", prog_name);
+ piglit_report_result(PIGLIT_FAIL);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+ int samples;
+ /* At present fragment shader supports only fixed number of
+ * attachments (3)
+ */
+ int num_attachments = 3;
+
+ if (argc < 2)
+ print_usage_and_exit(argv[0]);
+ {
+ char *endptr = NULL;
+ samples = strtol(argv[1], &endptr, 0);
+ if (endptr != argv[1] + strlen(argv[1]))
+ print_usage_and_exit(argv[0]);
+ }
+
+ piglit_require_extension("GL_ARB_framebuffer_object");
+ piglit_require_extension("GL_ARB_vertex_array_object");
+ piglit_require_extension("GL_EXT_framebuffer_multisample");
+
+ int pattern_width = piglit_width / 2;
+ int pattern_height = piglit_height / num_attachments;
+
+ piglit_ortho_projection(pattern_width,
+ pattern_height,
+ GL_TRUE);
+
+ /* Skip the test if samples > GL_MAX_SAMPLES */
+ GLint max_samples;
+ glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+
+ if (samples < 1 || samples > max_samples)
+ piglit_report_result(PIGLIT_SKIP);
+
+ ms_fbo_and_draw_buffers_setup(samples,
+ pattern_width,
+ pattern_height,
+ num_attachments,
+ GL_COLOR_BUFFER_BIT,
+ GL_RGBA /* color_buffer_zero_format */);
+ shader_compile(true /* sample_alpha_to_coverage */,
+ false /* dual_src_blend */,
+ false /* frag_out_zero_write */);
+}
+
+enum piglit_result
+piglit_display()
+{
+ bool pass = true;
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
+ glClearColor(0.0, 0.0, 0.0, 1.0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ allocate_data_arrays();
+
+ draw_test_image(true /* sample_alpha_to_coverage */,
+ false /* sample_alpha_to_one */);
+
+ pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
+
+ /* Free the memory allocated for data arrays */
+ free_data_arrays();
+
+ if (!piglit_automatic)
+ piglit_present_results();
+
+ /* The fragment colors are undefined in this test. So, we can't probe
+ * the pixels. If test executes to completion without error, return
+ * PIGLIT_PASS.
+ */
+ return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
--
2.5.5
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