[Piglit] [PATCH 03/12] msaa: Add test to verify sample-alpha-to-one with multiple draw buffers
Anuj Phogat
anuj.phogat at gmail.com
Mon Jul 16 15:50:52 PDT 2012
When rendering to multiple draw buffers, GL_SAMPLE_TO_ONE should modify
the alpha values sent to each draw buffer.
OpenGL 3.3 specification's section 4.1.3 is little unclear about the exact
behavior in above mentioned case. So, this test assumes the behavior shown
by NVIDIA's proprietary drivers.
Reviewed-by: Paul Berry<stereotype441 at gmail.com>
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
tests/all.tests | 6 +
.../ext_framebuffer_multisample/CMakeLists.gl.txt | 2 +
.../draw-buffers-alpha-to-one.cpp | 152 ++++++++++++++++++++
3 files changed, 160 insertions(+), 0 deletions(-)
create mode 100644 tests/spec/ext_framebuffer_multisample/draw-buffers-alpha-to-one.cpp
diff --git a/tests/all.tests b/tests/all.tests
index 5408e00..b8faaa3 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -1430,6 +1430,12 @@ for num_samples in MSAA_SAMPLE_COUNTS:
ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
for num_samples in MSAA_SAMPLE_COUNTS:
+ test_name = ' '.join(['draw-buffers-alpha-to-one', str(num_samples)])
+ executable = 'ext_framebuffer_multisample-{0} -auto'.format(
+ test_name)
+ ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
+
+for num_samples in MSAA_SAMPLE_COUNTS:
test_name = ' '.join(['bitmap', str(num_samples)])
executable = 'ext_framebuffer_multisample-{0} -auto'.format(
test_name)
diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index b2b7b51..716e4f3 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -16,6 +16,8 @@ piglit_add_executable (ext_framebuffer_multisample-blit-mismatched-sizes common.
piglit_add_executable (ext_framebuffer_multisample-blit-mismatched-formats common.cpp blit-mismatched-formats.cpp)
piglit_add_executable (ext_framebuffer_multisample-clear common.cpp clear.cpp)
piglit_add_executable (ext_framebuffer_multisample-clip-and-scissor-blit common.cpp clip-and-scissor-blit.cpp)
+piglit_add_executable (ext_framebuffer_multisample-draw-buffers-alpha-to-one common.cpp
+ draw-buffers-common.cpp draw-buffers-alpha-to-one.cpp)
piglit_add_executable (ext_framebuffer_multisample-dlist dlist.c)
piglit_add_executable (ext_framebuffer_multisample-enable-flag enable-flag.cpp common.cpp)
piglit_add_executable (ext_framebuffer_multisample-formats common.cpp formats.cpp)
diff --git a/tests/spec/ext_framebuffer_multisample/draw-buffers-alpha-to-one.cpp b/tests/spec/ext_framebuffer_multisample/draw-buffers-alpha-to-one.cpp
new file mode 100644
index 0000000..66bfd1c
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/draw-buffers-alpha-to-one.cpp
@@ -0,0 +1,152 @@
+/*
+ * 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.
+ */
+
+#include "draw-buffers-common.h"
+
+/**
+ * \file draw-buffers-alpha-to-one.cpp
+ *
+ * Verify sample alpha to one with multiple draw buffers
+ *
+ * When rendering to multiple draw buffers, GL_SAMPLE_ALPHA_TO_ONE should
+ * modify the alpha values sent to each draw buffer. OpenGL 3.3 specification's
+ * section 4.1.3 (page 196 of pdf) is little unclear about the exact behavior
+ * in above mentioned case:
+ *
+ * "All alpha values in this section refer only to the alpha component of the
+ * fragment shader output linked to color number zero, index zero (see section
+ * 3.9.2) if a fragment shader is in use, or the alpha component of the result
+ * of fixed-function fragment shading. If the fragment shader does not write to
+ * this output, the alpha value is undefined."
+ *
+ * And later in the same section it is stated that:
+ *
+ * "Next, if SAMPLE_ALPHA_TO_ONE is enabled, each alpha value is replaced by
+ * the maximum representable alpha value for fixed-point color buffers, or by
+ * 1.0 for floating-point buffers. Otherwise, the alpha values are not changed."
+ *
+ * By reading above two references together, specification seems to suggest that
+ * alpha values for only draw buffer zero will be modified when GL_SAMPLE_TO_ONE.
+ * is enabled. But with NVIDIA's proprietary drivers this test verifies that
+ * alpha values for all the draw buffers will be modified. In my opinion, this
+ * section needs clarification from khronos.
+ *
+ * At present test is based on the behavior observed with NVIDIA's proprietary
+ * drivers.
+ *
+ * This test operates by drawing a pattern in multisample FBO to generate
+ * reference and test images for all the draw buffers. Reference images are drawn
+ * to right half of window system draw buffer and test images to left half.
+ *
+ * Compare the left and right halves of window system frame buffer to verify
+ * the test image.
+ *
+ * Author: Anuj Phogat <anuj.phogat at gmail.com>
+ */
+
+PIGLIT_GL_TEST_MAIN(512 /*window_width*/,
+ 768 /*window_height*/,
+ GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA)
+
+static int samples;
+
+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)
+{
+ /* 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_gl_version(30);
+
+ 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 > 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);
+ shader_compile();
+}
+
+enum piglit_result
+piglit_display()
+{
+ bool pass = true;
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+ glClearColor(0.0, 0.0, 0.0, 1.0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ allocate_data_arrays();
+
+ draw_reference_image(false /* sample_alpha_to_coverage */,
+ true /* sample_alpha_to_one */);
+
+ draw_test_image(false /* sample_alpha_to_coverage */,
+ true /* sample_alpha_to_one */);
+
+ pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
+
+ glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+ pass = piglit_probe_rect_halves_equal_rgba(0, 0,
+ piglit_width,
+ piglit_height)
+ && pass;
+
+ /* Free the memory allocated for data arrays */
+ free_data_arrays();
+
+ if (!piglit_automatic)
+ piglit_present_results();
+
+ return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
--
1.7.7.6
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