[Piglit] [PATCH v2] arb_provoking_vertex: Test flat shading with clipped geometry

[Danylo Piliaiev]

There is a hardware bug in i965/gen9+ with provoking vertices.
Test if workaround works correctly.

Ref: https://bugs.freedesktop.org/show_bug.cgi?id=103047

v2: - Vertices now have distinctive color
    - Update  message to reflect a nature of the bug which was
      clarified by Kenneth. He will also provide workaround later.

Signed-off-by: Danylo Piliaiev <danylo.piliaiev at globallogic.com>
---
 tests/opengl.py                                    |  1 +
 tests/spec/arb_provoking_vertex/CMakeLists.gl.txt  |  1 +
 .../clipped-geometry-flatshading.c                 | 81 ++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 tests/spec/arb_provoking_vertex/clipped-geometry-flatshading.c

diff --git a/tests/opengl.py b/tests/opengl.py
index 3109a5e..313b22b 100644
--- a/tests/opengl.py
+++ b/tests/opengl.py
@@ -2205,6 +2205,7 @@ with profile.test_list.group_manager(
     g(['arb-provoking-vertex-control'], run_concurrent=False)
     g(['arb-provoking-vertex-initial'], run_concurrent=False)
     g(['arb-provoking-vertex-render'], run_concurrent=False)
+    g(['arb-provoking-vertex-clipped-geometry-flatshading'], run_concurrent=False)
     g(['arb-quads-follow-provoking-vertex'], run_concurrent=False)
     g(['arb-xfb-before-flatshading'], run_concurrent=False)
 
diff --git a/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt b/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
index 6dd15bb..3acffc6 100644
--- a/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
+++ b/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
@@ -11,6 +11,7 @@ link_libraries (
 piglit_add_executable (arb-provoking-vertex-control provoking-vertex-control.c)
 piglit_add_executable (arb-provoking-vertex-initial provoking-vertex-initial.c)
 piglit_add_executable (arb-provoking-vertex-render render.c)
+piglit_add_executable (arb-provoking-vertex-clipped-geometry-flatshading clipped-geometry-flatshading.c)
 piglit_add_executable (arb-quads-follow-provoking-vertex quads-follow-provoking-vertex.c)
 piglit_add_executable (arb-xfb-before-flatshading xfb-before-flatshading.c)
 
diff --git a/tests/spec/arb_provoking_vertex/clipped-geometry-flatshading.c b/tests/spec/arb_provoking_vertex/clipped-geometry-flatshading.c
new file mode 100644
index 0000000..72acb4d
--- /dev/null
+++ b/tests/spec/arb_provoking_vertex/clipped-geometry-flatshading.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright © 2018 Danylo Piliaiev
+ *
+ * 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 provoking vertex works as expected when part of the geometry
+ * is clipped when flat shading is enabled.
+ *
+ * https://bugs.freedesktop.org/show_bug.cgi?id=103047
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+	config.supports_gl_compat_version = 10;
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+PIGLIT_GL_TEST_CONFIG_END
+
+void
+piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_EXT_provoking_vertex");
+	piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
+
+	glShadeModel(GL_FLAT);
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	static const float red[3] = {1, 0, 0},
+		green[3] = {0, 1, 0},
+		blue[3] = {0, 0, 1},
+		yellow[3] = {1, 1, 0},
+		cyan[3] = {0, 1, 1};
+
+	bool pass = true;
+
+	glClear(GL_COLOR_BUFFER_BIT);
+	glProvokingVertexEXT(GL_LAST_VERTEX_CONVENTION_EXT);
+
+	const int y1 = piglit_height / 3;
+
+	glBegin(GL_TRIANGLE_STRIP);
+		glColor3fv(cyan);
+		glVertex3i(piglit_width + 1, y1, 0);
+		glColor3fv(yellow);
+		glVertex3i(piglit_width + 2, y1, 0);
+		glColor3fv(blue);
+		glVertex3i(piglit_width + 3, y1, 0);
+		glColor3fv(green);
+		glVertex3i(piglit_width / 2, y1 * 2, 0);
+		glColor3fv(red);
+		glVertex3i(piglit_width - 1, y1 * 2, 0);
+	glEnd();
+
+	pass = pass && piglit_probe_pixel_rgb(piglit_width - 2, y1 * 3 / 2, red);
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
2.7.4