arb_fb_no_attach: Test with an odd sample count

Adds a test that creates a framebuffer with no attachments and sets
the default sample count to 3. It then verifies that GL_SAMPLES for
the fbo is at least 3 and GL_SAMPLE_BUFFERS is 1. It also checks the
value of gl_NumSamples in the shader by writing to an SSBO with the
value to verify that it is the same as GL_SAMPLES.

Currently using an odd sample count with no attachments triggers an
assert in the i965 driver in Mesa.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93957
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>

2 files changed, 166 insertions, 0 deletions

diff --git a/tests/spec/arb_framebuffer_no_attachments/CMakeLists.gl.txt b/tests/spec/arb_framebuffer_no_attachments/CMakeLists.gl.txt
index bbc3177b8..38fc9e1af 100755
--- a/tests/spec/arb_framebuffer_no_attachments/CMakeLists.gl.txt
+++ b/tests/spec/arb_framebuffer_no_attachments/CMakeLists.gl.txt
@@ -12,3 +12,4 @@ piglit_add_executable (arb_framebuffer_no_attachments-minmax minmax.c)
 piglit_add_executable (arb_framebuffer_no_attachments-params params.c)
 piglit_add_executable (arb_framebuffer_no_attachments-atomic atomic.c)
 piglit_add_executable (arb_framebuffer_no_attachments-query query.c)
+piglit_add_executable (arb_framebuffer_no_attachments-roundup-samples roundup-samples.c)
diff --git a/tests/spec/arb_framebuffer_no_attachments/roundup-samples.c b/tests/spec/arb_framebuffer_no_attachments/roundup-samples.c
new file mode 100644
index 000000000..26ab300df
--- /dev/null
+++ b/tests/spec/arb_framebuffer_no_attachments/roundup-samples.c
@@ -0,0 +1,165 @@
+/*
+ * 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.
+ */
+
+/**
+ * \file roundup-samples.c
+ *
+ * Tests that requesting an odd number of samples doesn't break
+ * anything. The implementation should round this up to the next
+ * supported value. Technically the implementation is probably allowed
+ * to support the odd number of samples so it doesn't report this as a
+ * failure.
+ *
+ * Bug #93957
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_core_version = 31;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+#define REQUEST_N_SAMPLES 3
+
+const char *vs_source =
+	"#version 140\n"
+	"\n"
+	"in vec4 piglit_vertex;\n"
+	"\n"
+	"void\n"
+	"main()\n"
+	"{\n"
+	"        gl_Position = piglit_vertex;\n"
+	"}\n";
+
+const char *fs_source =
+	"#version 140\n"
+	"#extension GL_ARB_sample_shading : require\n"
+	"#extension GL_ARB_shader_storage_buffer_object : require\n"
+	"\n"
+	"layout (std140, binding=0) buffer shader_data\n"
+	"{\n"
+	"        int num_samples;\n"
+	"};\n"
+	"\n"
+	"void\n"
+	"main()\n"
+	"{\n"
+	"        num_samples = gl_NumSamples;\n"
+	"}\n";
+
+enum piglit_result
+piglit_display(void)
+{
+	return PIGLIT_FAIL;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	GLuint fbo;
+	GLint prog;
+	GLuint ssbo;
+	bool pass = true;
+	GLint actual_n_samples, actual_sample_buffers;
+	GLint shader_n_samples = 0;
+
+	piglit_require_gl_version(31);
+	piglit_require_extension("GL_ARB_framebuffer_no_attachments");
+	piglit_require_extension("GL_ARB_shader_storage_buffer_object");
+	piglit_require_extension("GL_ARB_sample_shading");
+
+	/* Create fbo with no attachments. */
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+	/* Setup default width, height and number of samples */
+	glFramebufferParameteri(GL_FRAMEBUFFER,
+				GL_FRAMEBUFFER_DEFAULT_WIDTH,
+				1);
+	glFramebufferParameteri(GL_FRAMEBUFFER,
+				GL_FRAMEBUFFER_DEFAULT_HEIGHT,
+				1);
+	glFramebufferParameteri(GL_FRAMEBUFFER,
+				GL_FRAMEBUFFER_DEFAULT_SAMPLES,
+				REQUEST_N_SAMPLES);
+
+	/* Check that fbo is marked complete. */
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
+	    GL_FRAMEBUFFER_COMPLETE)
+		piglit_report_result(PIGLIT_SKIP);
+
+	glGenBuffers(1, &ssbo);
+	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, ssbo);
+	glBufferData(GL_SHADER_STORAGE_BUFFER,
+		     sizeof (shader_n_samples),
+		     &shader_n_samples,
+		     GL_DYNAMIC_COPY);
+
+	prog = piglit_build_simple_program(vs_source, fs_source);
+
+	glUseProgram(prog);
+
+	piglit_draw_rect(-1, -1, 2, 2);
+
+	glMemoryBarrier(GL_BUFFER_UPDATE_BARRIER_BIT);
+
+	glGetIntegerv(GL_SAMPLES, &actual_n_samples);
+	glGetIntegerv(GL_SAMPLE_BUFFERS, &actual_sample_buffers);
+	glGetBufferSubData(GL_SHADER_STORAGE_BUFFER,
+			   0, /* offset */
+			   sizeof (shader_n_samples),
+			   &shader_n_samples);
+
+	printf("Requested samples                : %i\n"
+	       "glGetIntegerv(GL_SAMPLES)        : %i\n"
+	       "glGetIntegerv(GL_SAMPLE_BUFFERS) : %i\n"
+	       "gl_NumSamples from shader        : %u\n",
+	       REQUEST_N_SAMPLES,
+	       actual_n_samples,
+	       actual_sample_buffers,
+	       shader_n_samples);
+
+	if (actual_n_samples < REQUEST_N_SAMPLES) {
+		printf("FAIL: GL_SAMPLES is too small\n");
+		pass = false;
+	}
+
+	if (actual_sample_buffers != 1) {
+		printf("FAIL: GL_SAMPLE_BUFFERS should be 1\n");
+		pass = false;
+	}
+
+	if (shader_n_samples != actual_n_samples) {
+		printf("FAIL: GL_SAMPLES does not match gl_NumSamples\n");
+		pass = false;
+	}
+
+	glDeleteBuffers(1, &ssbo);
+	glDeleteFramebuffers(1, &fbo);
+	glDeleteProgram(prog);
+
+	piglit_report_result(pass ? PIGLIT_PASS : PIGLIT_FAIL);
+}