[Piglit] [PATCH] Add negative test for GL_SAMPLE_ALPHA_TO_ONE

Anuj Phogat anuj.phogat at gmail.com
Tue Jun 26 17:46:20 PDT 2012


This test varifies that alpha value is not changed with
GL_SAMPLE_ALPHA_TO_ONE enabled if GL_MULTISAMPLE is disabled
or buffer is not a multisample buffer.

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 tests/all.tests                                    |    6 +
 .../ext_framebuffer_multisample/CMakeLists.gl.txt  |    1 +
 .../negative-sample-alpha-to-one.cpp               |  296 ++++++++++++++++++++
 3 files changed, 303 insertions(+), 0 deletions(-)
 create mode 100644 tests/spec/ext_framebuffer_multisample/negative-sample-alpha-to-one.cpp

diff --git a/tests/all.tests b/tests/all.tests
index 215ac9c..f6a9a9e 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -1423,6 +1423,12 @@ for num_samples in MSAA_SAMPLE_COUNTS:
         ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
 
 for num_samples in MSAA_SAMPLE_COUNTS:
+        test_name = ' '.join(['negative-sample-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 338a5e8..74db2a5 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -26,6 +26,7 @@ piglit_add_executable (ext_framebuffer_multisample-negative-copyteximage negativ
 piglit_add_executable (ext_framebuffer_multisample-negative-max-samples negative-max-samples.c)
 piglit_add_executable (ext_framebuffer_multisample-negative-mismatched-samples negative-mismatched-samples.c)
 piglit_add_executable (ext_framebuffer_multisample-negative-readpixels negative-readpixels.c)
+piglit_add_executable (ext_framebuffer_multisample-negative-sample-alpha-to-one common.cpp negative-sample-alpha-to-one.cpp)
 piglit_add_executable (ext_framebuffer_multisample-point-smooth common.cpp point-smooth.cpp)
 piglit_add_executable (ext_framebuffer_multisample-polygon-smooth common.cpp polygon-smooth.cpp)
 piglit_add_executable (ext_framebuffer_multisample-polygon-stipple common.cpp polygon-stipple.cpp)
diff --git a/tests/spec/ext_framebuffer_multisample/negative-sample-alpha-to-one.cpp b/tests/spec/ext_framebuffer_multisample/negative-sample-alpha-to-one.cpp
new file mode 100644
index 0000000..7429223
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/negative-sample-alpha-to-one.cpp
@@ -0,0 +1,296 @@
+/*
+ * 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 "common.h"
+
+/**
+ * \file negative-sample-alpha-to-one.cpp
+ *
+ * Verify that alpha values are not modified if GL_SAMPLE_ALPHA_TO_ONE is
+ * enabled and GL_MULTISAMPLE is disabled in a multisample buffer.
+ *
+ * Also, verify that alpha values are not modified if GL_SAMPLE_ALPHA_TO_ONE
+ * is enabled and the buffer is single-sampled.
+ *
+ * Author: Anuj Phogat <anuj.phogat at gmail.com>
+ */
+
+PIGLIT_GL_TEST_MAIN(512 /*window_width*/,
+		    256 /*window_height*/,
+		    GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA)
+
+const int pattern_width = 256; const int pattern_height = 256;
+static Fbo ms_fbo, resolve_fbo;
+static GLbitfield buffer_to_test;
+
+static GLfloat *color = NULL;
+static GLint num_samples;
+static GLint num_rects;
+static GLint prog;
+static GLint color_loc;
+static GLint depth_loc;
+
+static const float bg_color[4] =
+	{0.4, 0.2, 0.6, 0.8};
+
+
+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)
+{
+	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);
+
+	unsigned int indices[6] = {0, 1, 2, 0, 2, 3};
+
+	for (int i = 0; i < num_rects; i++) {
+
+		float vertex_data[4][2] = {
+		{ 0.0f + i * (pattern_width / num_rects),   0.0f	   },
+		{ 0.0f + i * (pattern_width / num_rects),   pattern_height },
+		{ (i + 1.0f) * (pattern_width / num_rects), pattern_height },
+		{ (i + 1.0f) * (pattern_width / num_rects), 0.0f	   } };
+
+		glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE,
+				      sizeof(vertex_data[0]),
+				      (void *) vertex_data);
+
+		glUniform4fv(color_loc, 1, (color + i * 4));
+		glUniform1f(depth_loc, 0.0f);
+		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT,
+			       (void *) indices);
+	}
+	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);
+}
+
+
+bool
+test_sample_alpha_to_one(Fbo *test_fbo)
+{
+	bool result = true;
+	/* Draw test pattern in multisample ms_fbo with GL_SAMPLE_COVERAGE
+	 * enabled
+	 */
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, test_fbo->handle);
+	draw_pattern(true);
+
+	if (test_fbo->handle == ms_fbo.handle) {
+		/* Blit test_fbo to resolve_fbo */
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, test_fbo->handle);
+		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolve_fbo.handle);
+		glBlitFramebuffer(0, 0, pattern_width, pattern_height,
+				  0, 0, pattern_width, pattern_height,
+				  buffer_to_test, GL_NEAREST);
+	}
+
+	/* Blit resolve_fbo to the left half of window system framebuffer.
+	 * This is the test image.
+	 */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, resolve_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);
+
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+	result = piglit_probe_rect_halves_equal_rgba(0, 0, piglit_width,
+						   piglit_height) && result;
+
+	result = piglit_check_gl_error(GL_NO_ERROR) && result;
+	return result;
+}
+
+void
+draw_reference_image(void)
+{
+	/* 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 resolve_fbo */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolve_fbo.handle);
+	glBlitFramebuffer(0, 0, pattern_width, pattern_height,
+			  0, 0, pattern_width, pattern_height,
+			  buffer_to_test, GL_NEAREST);
+
+	/* 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, resolve_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);
+}
+
+void
+allocate_data_arrays(void)
+{
+	/* Draw 2N + 1 rectangles for N samples, each with a unique color */
+	num_rects = 2 * num_samples + 1;
+
+	/* Allocate data arrays based on number of samples used */
+	color = (float *) malloc(num_rects * 4 * sizeof(float));
+
+	for(int i = 0; i < num_rects; i++) {
+		color[i * 4 + 0] = (sin(i * 4 + 0) + 1) / 2;
+		color[i * 4 + 1] = (sin(i * 4 + 1) + 1) / 2;
+		color[i * 4 + 2] = (sin(i * 4 + 2) + 1) / 2;
+		color[i * 4 + 3] = (sin(i * 4 + 3) + 1) / 2;
+	}
+}
+
+void
+free_data_arrays(void)
+{
+	if(color != NULL) {
+		free(color);
+		color = NULL;
+	}
+}
+
+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 */
+	GLint max_samples;
+	glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+
+	if (num_samples > max_samples)
+		piglit_report_result(PIGLIT_SKIP);
+
+	ms_fbo.setup(FboConfig(num_samples, pattern_width, pattern_height));
+	resolve_fbo.setup(FboConfig(0, pattern_width, pattern_height));
+
+	if (!piglit_check_gl_error(GL_NO_ERROR)) {
+                printf("Error setting up frame buffer objects\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	buffer_to_test = GL_COLOR_BUFFER_BIT;
+
+	/* Enable blending to easily detect any change in alpha values
+	 * caused by GL_SAMPLE_ALPHA_TO_ONE
+	 */
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	shader_compile();
+}
+
+enum piglit_result
+piglit_display()
+{
+	bool pass = true;
+	glClearColor(0.0, 0.0, 0.0, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	allocate_data_arrays();
+	draw_reference_image();
+
+	/* Test multisample fbo with GL_SAMPLE_ALPHA_TO_ONE enabled but
+	 * GL_MULTISAMPLE disabled */
+	glDisable(GL_MULTISAMPLE);
+
+	pass = test_sample_alpha_to_one(&ms_fbo) && pass;
+
+	glEnable(GL_MULTISAMPLE);
+
+	/* Test singlesample fbo with GL_SAMPLE_ALPHA_TO_ONE enabled */
+	pass = test_sample_alpha_to_one(&resolve_fbo) && pass;
+
+	free_data_arrays();
+
+	if (!piglit_automatic)
+		piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
1.7.7.6



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