[Piglit] [PATCH] gl-1.3-alpha_to_coverage_nop: new test of no-op GL_SAMPLE_ALPHA_TO_COVERAGE

[Brian Paul]

Currently fails with llvmpipe.  Fragments with alpha <= 0.5 are discarded.
Passes with softpipe, NVIDIA driver.

v2: test with GL_MULTISAMPLE both enabled and disabled, fix all.py entry
---
 tests/all.py                              |   1 +
 tests/spec/CMakeLists.txt                 |   1 +
 tests/spec/gl-1.3/CMakeLists.gl.txt       |  13 ++++
 tests/spec/gl-1.3/CMakeLists.txt          |   1 +
 tests/spec/gl-1.3/alpha_to_coverage_nop.c | 110 ++++++++++++++++++++++++++++++
 5 files changed, 126 insertions(+)
 create mode 100644 tests/spec/gl-1.3/CMakeLists.gl.txt
 create mode 100644 tests/spec/gl-1.3/CMakeLists.txt
 create mode 100644 tests/spec/gl-1.3/alpha_to_coverage_nop.c

diff --git a/tests/all.py b/tests/all.py
index a448331..b069548 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -840,6 +840,7 @@ with profile.group_manager(
     g(['gl-1.1-xor'])
     g(['gl-1.1-xor-copypixels'])
     g(['gl-1.2-texture-base-level'])
+    g(['gl-1.3-alpha_to_coverage_nop'])
     g(['hiz'], run_concurrent=False)
     g(['infinite-spot-light'], run_concurrent=False)
     g(['line-aa-width'], run_concurrent=False)
diff --git a/tests/spec/CMakeLists.txt b/tests/spec/CMakeLists.txt
index 9b0f73e..9972785 100644
--- a/tests/spec/CMakeLists.txt
+++ b/tests/spec/CMakeLists.txt
@@ -106,6 +106,7 @@ add_subdirectory (glsl-es-3.00)
 add_subdirectory (gl-1.0)
 add_subdirectory (gl-1.1)
 add_subdirectory (gl-1.2)
+add_subdirectory (gl-1.3)
 add_subdirectory (gl-1.4)
 add_subdirectory (gl-1.5)
 add_subdirectory (gl-2.0)
diff --git a/tests/spec/gl-1.3/CMakeLists.gl.txt b/tests/spec/gl-1.3/CMakeLists.gl.txt
new file mode 100644
index 0000000..607d2c1
--- /dev/null
+++ b/tests/spec/gl-1.3/CMakeLists.gl.txt
@@ -0,0 +1,13 @@
+include_directories(
+	${GLEXT_INCLUDE_DIR}
+	${OPENGL_INCLUDE_PATH}
+)
+
+link_libraries (
+	piglitutil_${piglit_target_api}
+	${OPENGL_gl_LIBRARY}
+)
+
+piglit_add_executable (gl-1.3-alpha_to_coverage_nop alpha_to_coverage_nop.c)
+
+# vim: ft=cmake:
diff --git a/tests/spec/gl-1.3/CMakeLists.txt b/tests/spec/gl-1.3/CMakeLists.txt
new file mode 100644
index 0000000..4a012b9
--- /dev/null
+++ b/tests/spec/gl-1.3/CMakeLists.txt
@@ -0,0 +1 @@
+piglit_include_target_api()
\ No newline at end of file
diff --git a/tests/spec/gl-1.3/alpha_to_coverage_nop.c b/tests/spec/gl-1.3/alpha_to_coverage_nop.c
new file mode 100644
index 0000000..b343056
--- /dev/null
+++ b/tests/spec/gl-1.3/alpha_to_coverage_nop.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright © 2016 VMware, Inc.
+ *
+ * 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.
+ */
+
+
+/**
+ * Test that enabling GL_ALPHA_TO_COVERAGE has no effect for non-MSAA
+ * rendering.
+ */
+
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+	config.supports_gl_compat_version = 13;
+	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
+PIGLIT_GL_TEST_CONFIG_END
+
+
+void
+piglit_init(int argc, char **argv)
+{
+	/* nothing */
+}
+
+static bool
+test_coverage_nop(bool msaa_enabled)
+{
+	float alpha;
+
+	if (msaa_enabled)
+		glEnable(GL_MULTISAMPLE);
+	else
+		glDisable(GL_MULTISAMPLE);
+
+	/* Render quad with varying alpha value.  Make sure it draws
+	 * and is not missing because of some kind of MSAA coverage bug.
+	 */
+	for (alpha = 1.0; alpha >= 0.0; alpha -= 1.0/128) {
+		float expected[4] = {alpha, alpha, alpha, alpha};
+
+		glClear(GL_COLOR_BUFFER_BIT);
+		glColor4fv(expected);
+		piglit_draw_rect(-1, -1, 2, 2);
+
+		if (!piglit_probe_rect_rgba(0, 0, piglit_width, piglit_height,
+					    expected)) {
+			printf("Rect did not draw for alpha = %g "
+			       "with GL_MULTISAMPLE %s\n",
+			       alpha,
+			       msaa_enabled ? "enabled" : "disabled");
+			return false;
+		}
+
+		piglit_present_results();
+	}
+
+	return true;
+}
+
+
+enum piglit_result
+piglit_display(void)
+{
+	GLint samples;
+	bool pass;
+
+	glGetIntegerv(GL_SAMPLES, &samples);
+	if (samples != 0) {
+		printf("Unexpected GL_SAMPLES = %d\n", samples);
+		return PIGLIT_FAIL;
+	}
+
+	glGetIntegerv(GL_SAMPLE_BUFFERS, &samples);
+	if (samples != 0) {
+		printf("Unexpected GL_SAMPLE_BUFFERS = %d\n", samples);
+		return PIGLIT_FAIL;
+	}
+
+	glClearColor(1, 0, 0, 0);
+
+	/* Enabling GL_SAMPLE_ALPHA_TO_COVERAGE should have no effect
+	 * with a non-MSAA drawing surface.
+	 */
+	glEnable(GL_SAMPLE_ALPHA_TO_COVERAGE);
+
+	pass = test_coverage_nop(true);
+	pass = test_coverage_nop(false) && pass;
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
1.9.1