[Piglit] [PATCH] Add test to turn on/off MSAA in a FBO

[Anuj Phogat]

This test varifies turning MSAA ON/OFF in color attachment of a FBO
by passing different sample count to glRenderbufferStorageMultisample().

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
Note: This patch can be used only after applying following patch:
[Patch] Split accuracy test to allow new multisample tests utilize this code.
Above patch has been posted to piglit mailing list.

 .../ext_framebuffer_multisample/CMakeLists.gl.txt  |    1 +
 .../spec/ext_framebuffer_multisample/turn-on-off.c |  156 ++++++++++++++++++++
 2 files changed, 157 insertions(+), 0 deletions(-)
 create mode 100644 tests/spec/ext_framebuffer_multisample/turn-on-off.c

diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index 3548074..27833c8 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -22,3 +22,4 @@ piglit_add_executable (ext_framebuffer_multisample-negative-readpixels negative-
 piglit_add_executable (ext_framebuffer_multisample-renderbuffer-samples renderbuffer-samples.c)
 piglit_add_executable (ext_framebuffer_multisample-renderbufferstorage-samples renderbufferstorage-samples.c)
 piglit_add_executable (ext_framebuffer_multisample-samples samples.c)
+piglit_add_executable (ext_framebuffer_multisample-turn-on-off common.cpp turn-on-off.c)
diff --git a/tests/spec/ext_framebuffer_multisample/turn-on-off.c b/tests/spec/ext_framebuffer_multisample/turn-on-off.c
new file mode 100644
index 0000000..b637b52
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/turn-on-off.c
@@ -0,0 +1,156 @@
+/*
+ * 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 turn-on-off.c
+ *
+ * Algorithm for this test case:
+ * 1. Render the geometry to left half of default framebuffer and read color
+ *    buffer in to a local buffer.
+ *
+ * 2. Create a FBO with MSAA turned OFF. Compare the rendered geometry with
+ *    buffer in Step 1. It is expected to match.
+ *
+ * 3. Turn ON MSAA in FBO. Render the scene, draw reference image and measure
+ *    the accuracy of MSAA. This varifies if MSAA is turned ON.
+ *
+ * 4. Turn OFF MSAA in FBO. Render the scene and compare to the buffer in
+ *    step 1. It is expected to match.
+ *
+ * Test image is rendered in to left half of framebuffer.
+ * Reference image is rendered in to right half of framebuffer.
+ *
+ * TODO: Add testing for depth and stencil buffers.
+ */
+
+int piglit_width = 512; int piglit_height = 256;
+int piglit_window_mode = GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA;
+
+int num_samples = 0;
+bool small = false;
+bool combine_depth_stencil = false;
+
+/* Define extern variables declared in common.cpp */
+const int pattern_width = 256; const int pattern_height = 256;
+const int supersample_factor = 16;
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = true;
+	GLint w = pattern_width, h = pattern_height;
+	GLfloat *color_buffer = NULL;
+
+	/* Set flag to render to default framebuffer */
+	draw_test_image(true);
+
+	/* Read color buffer */
+	color_buffer = malloc(w * h * 4 * sizeof(float));
+	glReadPixels(0, 0, w, h, GL_RGBA, GL_FLOAT, color_buffer);
+
+	/* Draw to FBO with single sample render buffer. i.e. MSAA turned OFF.
+	 * Set use_render_buffer flag to verify glRenderbufferStorageMultisample()
+	 * with zero sample count turns off MSAA.
+	 */
+	fbo_set_samples(0, true, small, combine_depth_stencil);
+
+	draw_test_image(false);
+	/* Compare rendered scene with color_buffer */
+	pass = piglit_probe_image_rgba(0, 0, w, h, color_buffer)
+	       && pass;
+
+	/* Switch ON MSAA in this FBO by passing num_samples > 0 */
+	fbo_set_samples(num_samples, false, small, combine_depth_stencil);
+	/* Draw test image in multisample FBO */
+	draw_test_image(false);
+	/* Draw a reference image for MSAA */
+	draw_reference_image();
+	/* Measure the accuracy of MSAA in multisample FBO by comparing the
+	 * test image to reference image. This varifies if MSAA is actually
+	 * switched on.
+	 */
+	pass = measure_accuracy() && pass;
+
+	/* Switch OFF MSAA again in this FBO */
+	fbo_set_samples(0, true, small, combine_depth_stencil);
+	draw_test_image(false);
+
+	/* Compare rendered scene with color_buffer */
+	pass = piglit_probe_image_rgba(0, 0, w, h, color_buffer)
+	       && pass;
+
+	if (!piglit_automatic)
+		piglit_present_results();
+	return (pass ? PIGLIT_PASS : PIGLIT_FAIL);
+}
+
+void
+print_usage_and_exit(char *prog_name)
+{
+	printf("Usage: %s <num_samples> <test_type> [options]\n"
+	       "  where <test_type> is one of:\n"
+	       "    color: test turning MSAA on/off in color attachment of FBO\n"
+	       "Available options:\n"
+	       "    small: use a very small (16x16) MSAA buffer\n"
+	       "    depthstencil: use a combined depth/stencil buffer\n",
+	       prog_name);
+
+	piglit_report_result(PIGLIT_FAIL);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	GLint i, max_samples;
+	if (argc < 3)
+		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]);
+	}
+
+	for (i = 3; i < argc; ++i) {
+		if (strcmp(argv[i], "small") == 0) {
+			small = true;
+		} else if (strcmp(argv[i], "depthstencil") == 0) {
+			combine_depth_stencil = true;
+		} else {
+			print_usage_and_exit(argv[0]);
+		}
+	}
+
+	piglit_require_gl_version(30);
+	piglit_require_GLSL_version(130);
+
+	/* Skip the test if num_samples > GL_MAX_SAMPLES */
+	glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+	if (num_samples > max_samples) {
+		printf("Sample count not supported : %d\n", num_samples);
+		piglit_report_result(PIGLIT_SKIP);
+	}
+
+	test_init("color", num_samples, small, combine_depth_stencil);
+}
-- 
1.7.7.6