[Piglit] =?y?q?=5BPATCH=204/4=5D=20Add=20test=20to=20verify=20sample=20alpha=20to=20one=20with=20multisample=20fbo?=

anuj.phogat at gmail.com anuj.phogat at gmail.com
Fri Jun 8 14:46:04 PDT 2012


From: Anuj Phogat <anuj.phogat at gmail.com>

This test varifies that with GL_SAMPLE_ALPHA_TO_ONE enabled, each sample's
alpha value is replaced by maximum alpha value i.e. 1.0.

Verified the test case using proprietary NVIDIA drivers.

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 tests/all.tests                                    |    6 +
 .../ext_framebuffer_multisample/CMakeLists.gl.txt  |    1 +
 .../sample-alpha-to-one.cpp                        |  287 ++++++++++++++++++++
 3 files changed, 294 insertions(+), 0 deletions(-)
 create mode 100644 tests/spec/ext_framebuffer_multisample/sample-alpha-to-one.cpp

diff --git a/tests/all.tests b/tests/all.tests
index 0e531b8..946874c 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -1400,6 +1400,12 @@ for num_samples in (2, 4, 8, 16, 32):
                         test_name)
                 ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
 
+for num_samples in (2, 4, 8, 16, 32):
+	test_name = ' ' .join(['sample-alpha-to-one', str(num_samples)])
+	executable = 'ext_framebuffer_multisample-{0} -auto'.format(
+	        test_name)
+	ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
+
 ext_framebuffer_object = Group()
 spec['EXT_framebuffer_object'] = ext_framebuffer_object
 add_fbo_stencil_tests(ext_framebuffer_object, 'GL_STENCIL_INDEX1')
diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index a6595fa..f482581 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -28,6 +28,7 @@ piglit_add_executable (ext_framebuffer_multisample-renderbufferstorage-samples r
 piglit_add_executable (ext_framebuffer_multisample-samples samples.c)
 piglit_add_executable (ext_framebuffer_multisample-sample-coverage common.cpp sample-coverage.cpp)
 piglit_add_executable (ext_framebuffer_multisample-sample-alpha-to-coverage common.cpp sample-alpha-to-coverage.cpp)
+piglit_add_executable (ext_framebuffer_multisample-sample-alpha-to-one common.cpp sample-alpha-to-one.cpp)
 piglit_add_executable (ext_framebuffer_multisample-turn-on-off common.cpp turn-on-off.cpp)
 piglit_add_executable (ext_framebuffer_multisample-unaligned-blit common.cpp unaligned-blit.cpp)
 piglit_add_executable (ext_framebuffer_multisample-upsample common.cpp upsample.cpp)
diff --git a/tests/spec/ext_framebuffer_multisample/sample-alpha-to-one.cpp b/tests/spec/ext_framebuffer_multisample/sample-alpha-to-one.cpp
new file mode 100644
index 0000000..76d288b
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/sample-alpha-to-one.cpp
@@ -0,0 +1,287 @@
+/*
+ * 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:
+static float coverage[4];
+ *
+ * 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 "common.h"
+
+/**
+ * \file sample-alpha-to-one.cpp
+ *
+ * This test operates by computing the expected color values when
+ * GL_SAMPLE_ALPHA_TO_ONE is disabled.
+ *
+ * Draw a test pattern with GL_SAMPLE_ALPHA_TO_ONE disabled and blit it to
+ * the right half of window system framebuffer. Probe the right half of
+ * framebuffer and compare with expected values.
+ *
+ * Compute the expected color values when GL_SAMPLE_ALPHA_TO_ONE is enabled.
+ * Draws the same test pattern for the second time in multisample buffer with
+ * GL_SAMPLE_ALPHA_TO_ONE enabled. Blits it in to left half of window system
+ * framebuffer.
+ *
+ * Probe the left half of window syetem framebuffer and compare with expected
+ * color values.
+ *
+ * Author: Anuj Phogat <anuj.phogat at gmail.com>
+ */
+
+int piglit_width = 512; int piglit_height = 256;
+int piglit_window_mode =
+	GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA | GLUT_DEPTH;
+const int pattern_width = 256; const int pattern_height = 256;
+
+static Fbo ms_fbo;
+static GLint num_samples;
+static float expected[4][4];
+static GLbitfield buffer_to_test;
+
+static const float bg_color[4] =
+	{0.0, 0.0, 1.0, 0.8};
+
+static const float color[4][4] = {
+	/* Red */
+	{1.0, 0.0, 0.0, 0.0},
+	/* Green */
+	{0.0, 1.0, 0.0, 0.25},
+	/* Yellow */
+	{1.0, 1.0, 0.0, 0.75},
+	/* Cyan */
+	{0.0, 1.0, 1.0, 1.0} };
+
+static GLint prog;
+static GLint color_loc;
+static GLint depth_loc;
+
+static const char *vert =
+	"#version 130\n"
+	"in vec2 pos;\n"
+	"uniform float depth;\n"
+	"void main()\n"
+	"{\n"
+	"  vec4 eye_pos = gl_ModelViewProjectionMatrix * vec4(pos, 0.0, 1.0);\n"
+	"  gl_Position = vec4(eye_pos.xy, depth, 1.0);\n"
+	"}\n";
+
+static const char *frag =
+	"#version 130\n"
+	"uniform vec4 color;\n"
+	"void main()\n"
+	"{\n"
+	"  gl_FragColor = color;\n"
+	"}\n";
+
+void
+shader_compile()
+{
+	/* Compile program */
+	GLint vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
+	GLint fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
+	prog = piglit_link_simple_program(vs, fs);
+
+	if (!piglit_link_check_status(prog)) {
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	glBindAttribLocation(prog, 0, "pos");
+	glEnableVertexAttribArray(0);
+
+	/* Set up uniforms */
+	glUseProgram(prog);
+	color_loc = glGetUniformLocation(prog, "color");
+	depth_loc = glGetUniformLocation(prog, "depth");
+}
+
+void
+draw_pattern(bool sample_alpha_to_one)
+{
+	float vertex_data[10][2] = {
+		{ 0,			 0 },
+		{ 0,			 pattern_height },
+		{ pattern_width / 4,	 pattern_height },
+		{ pattern_width / 4,	 0 },
+		{ pattern_width / 2,	 pattern_height },
+		{ pattern_width / 2,	 0 },
+		{ 3 * pattern_width / 4, pattern_height },
+		{ 3 * pattern_width / 4, 0 },
+		{ pattern_width,	 pattern_height },
+		{ pattern_width,	 0 },
+	};
+
+	unsigned int indices[24] = {0, 1, 2, 0, 2, 3,
+				    3, 2, 4, 3, 4, 5,
+				    5, 4, 6, 5, 6, 7,
+				    7, 6, 8, 7, 8, 9};
+	glUseProgram(prog);
+
+	glClearColor(bg_color[0], bg_color[1],
+		     bg_color[2], bg_color[3]);
+	glClear(buffer_to_test);
+
+	if (sample_alpha_to_one)
+		glEnable(GL_SAMPLE_ALPHA_TO_ONE);
+
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(vertex_data[0]),
+			      (void *) vertex_data);
+
+	for (int i = 0; i < 4; ++i) {
+		glUniform4fv(color_loc, 1, color[i]);
+		glUniform1f(depth_loc, 0.0);
+		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT,
+			       (void *) (indices + 6 * i));
+
+	}
+	if (sample_alpha_to_one)
+		glDisable (GL_SAMPLE_ALPHA_TO_ONE);
+}
+
+void
+print_usage_and_exit(char *prog_name)
+{
+	printf("Usage: %s <num_samples>\n", prog_name);
+	piglit_report_result(PIGLIT_FAIL);
+}
+
+void
+compute_expected(void)
+{
+
+	/* Page 242 (page 258 of the PDF) of the OpenGL 3.0 spec says:
+	 * Next, if SAMPLE ALPHA TO ONE is enabled, each alpha value is
+	 * replaced by the maximum representable alpha value. Otherwise,
+	 * the alpha values are not changed.
+	 */
+	for(int i = 0; i < 4; i++) {
+		expected[i][0] = color[i][0];
+		expected[i][1] = color[i][1];
+		expected[i][2] = color[i][2];
+		expected[i][3] = 1.0 ;
+	}
+}
+
+bool probe_framebuffer_color(GLint x_offset, const float *expected)
+{
+	bool result = true;
+
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+	for(int i = 0; i< 4; i++) {
+		result = piglit_probe_rect_rgba(x_offset + i * (pattern_width / 4),
+						0,
+						pattern_width / 4,
+						pattern_height,
+						expected + 4 * i)
+			 && result;
+	}
+	return result;
+}
+
+bool
+test_sample_alpha_to_one(void)
+{
+	bool result = true;
+	compute_expected();
+	/* Now draw test pattern in mulisample ms_fbo with GL_SAMPLE_COVERAGE
+	 * enabled
+	 */
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle);
+	draw_pattern(true);
+
+	/* Blit ms_fbo to the left half of window system framebuffer. This
+	 * is the test image.
+	 */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	glBlitFramebuffer(0, 0, pattern_width, pattern_height,
+			  0, 0, pattern_width, pattern_height,
+			  buffer_to_test, GL_NEAREST);
+
+	/* Probe the left half of default framebuffer and compare to the
+	 * expected values */
+	if (buffer_to_test == GL_COLOR_BUFFER_BIT)
+		result = probe_framebuffer_color(0, expected[0]) && result;
+
+	result = piglit_check_gl_error(GL_NO_ERROR) && result;
+	return result;
+}
+void
+piglit_init(int argc, char **argv)
+{
+	if (argc < 2)
+		print_usage_and_exit(argv[0]);
+	{
+		char *endptr = NULL;
+		num_samples = strtol(argv[1], &endptr, 0);
+		if (endptr != argv[1] + strlen(argv[1]))
+			print_usage_and_exit(argv[0]);
+	}
+
+	piglit_require_gl_version(30);
+	piglit_ortho_projection(pattern_width, pattern_height, GL_TRUE);
+
+	/* Skip the test if num_samples > GL_MAX_SAMPLES or num_samples = 0 */
+	GLint max_samples;
+	glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+
+	if (num_samples > max_samples ||
+	    num_samples == 0)
+		piglit_report_result(PIGLIT_SKIP);
+
+	ms_fbo.setup(FboConfig(num_samples, pattern_width, pattern_height));
+	buffer_to_test = GL_COLOR_BUFFER_BIT;
+	shader_compile();
+}
+
+enum piglit_result
+piglit_display()
+{
+	bool pass = true;
+	glClearColor(0.0, 0.0, 0.0, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	/* Draw test pattern in  multisample ms_fbo with GL_SAMPLE_ALPHA_TO_ONE
+	 * disabled.
+	 */
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle);
+	ms_fbo.set_viewport();
+	draw_pattern(false);
+
+	/* Blit ms_fbo to the right half of window system framebuffer. This
+	 * is a reference image to see the visual difference when compared
+	 * to the test image.
+	 */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	glBlitFramebuffer(0, 0, pattern_width, pattern_height,
+			  pattern_width, 0, 2 * pattern_width, pattern_height,
+			  buffer_to_test, GL_NEAREST);
+	/* Probe the right half of default framebuffer and compare to the
+	 * expected values */
+	pass = probe_framebuffer_color(pattern_width, color[0]) && pass;
+
+	/* Now test multisample fbo with GL_SAMPLE_ALPHA_TO_ONE enabled */
+	pass = test_sample_alpha_to_one() && pass;
+
+	if (!piglit_automatic)
+		piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
1.7.7.6



More information about the Piglit mailing list