Test proper behavior of gl_MaxClipDistances and gl_MaxClipPlanes.

This patch adds a test to verify that if the implementation reports
support for GLSL version 1.30, the values of gl_MaxClipDistances and
gl_MaxClipPlanes (accessible via GLSL) match the values of
MAX_CLIP_DISTANCES and MAX_CLIP_PLANES queried using glGetIntegerv.

Furthermore, it checks that the value of MAX_CLIP_DISTANCES matches
the value of MAX_CLIP_PLANES (since the latter is a deprecated name
for the former), and that the value is at least 8 (since GLSL 1.30
requires at least 8 clip distances to be supported).

Tested using the nVidia proprietary Linux driver.

5 files changed, 189 insertions, 0 deletions

diff --git a/tests/all.tests b/tests/all.tests
index 0ec6ee33c..672c52854 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -847,6 +847,7 @@ add_shader_test_dir(spec['glsl-1.30']['execution'],
 spec['glsl-1.30']['linker'] = Group()
 spec['glsl-1.30']['linker']['clipping'] = Group()
 add_plain_test(spec['glsl-1.30']['linker']['clipping'], 'mixing-clip-distance-and-clip-vertex-disallowed')
+add_plain_test(spec['glsl-1.30']['execution']['clipping'], 'max-clip-distances')
 
 # Group AMD_conservative_depth
 spec['AMD_conservative_depth'] = Group()
diff --git a/tests/spec/glsl-1.30/execution/CMakeLists.txt b/tests/spec/glsl-1.30/execution/CMakeLists.txt
index 144a306f4..a768d27f4 100644
--- a/tests/spec/glsl-1.30/execution/CMakeLists.txt
+++ b/tests/spec/glsl-1.30/execution/CMakeLists.txt
@@ -1 +1,2 @@
 piglit_include_target_api()
+add_subdirectory (clipping)
diff --git a/tests/spec/glsl-1.30/execution/clipping/CMakeLists.gl.txt b/tests/spec/glsl-1.30/execution/clipping/CMakeLists.gl.txt
new file mode 100644
index 000000000..aae66ee89
--- /dev/null
+++ b/tests/spec/glsl-1.30/execution/clipping/CMakeLists.gl.txt
@@ -0,0 +1,17 @@
+
+include_directories(
+	${GLEXT_INCLUDE_DIR}
+	${OPENGL_INCLUDE_PATH}
+	${GLUT_INCLUDE_DIR}
+	${piglit_SOURCE_DIR}/tests/mesa/util
+	${piglit_SOURCE_DIR}/tests/util
+)
+
+link_libraries (
+	piglitutil
+	${OPENGL_gl_LIBRARY}
+	${OPENGL_glu_LIBRARY}
+	${GLUT_glut_LIBRARY}
+)
+
+add_executable (max-clip-distances max-clip-distances.c)
diff --git a/tests/spec/glsl-1.30/execution/clipping/CMakeLists.txt b/tests/spec/glsl-1.30/execution/clipping/CMakeLists.txt
new file mode 100644
index 000000000..144a306f4
--- /dev/null
+++ b/tests/spec/glsl-1.30/execution/clipping/CMakeLists.txt
@@ -0,0 +1 @@
+piglit_include_target_api()
diff --git a/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.c b/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.c
new file mode 100644
index 000000000..f03366598
--- /dev/null
+++ b/tests/spec/glsl-1.30/execution/clipping/max-clip-distances.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright © 2011 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 max-clip-distances.c
+ *
+ * From the GLSL 1.30 spec, section 7.4 (Built-In Constants):
+ *
+ *   "The following built-in constants are provided to vertex and
+ *   fragment shaders. The actual values used are implementation
+ *   dependent, but must be at least the value shown.
+ *
+ *   ...
+ *
+ *   const int gl_MaxClipDistances = 8;
+ *
+ *   ...
+ *
+ *   const int gl_MaxClipPlanes = 8; // deprecated"
+ *
+ * And from the GL 3.0 spec, section N.3 (Changed Tokens):
+ *
+ *   "New token names are introduced to be used in place of old,
+ *   inconsistent names.  However, the old token names continue to be
+ *   supported, for backwards compatibility with code written for
+ *   previous versions of OpenGL.
+ *
+ *   ...
+ *
+ *   New Token Name       Old Token Name
+ *   ...
+ *   MAX_CLIP_DISTANCES   MAX_CLIP_PLANES
+ *
+ * This test verifies that glGetIntegerv() returns the same result for
+ * the tokens MAX_CLIP_DISTANCES and MAX_CLIP_PLANES, that this value
+ * matches the value of gl_MaxClipDistances and gl_MaxClipPlanes
+ * defined in the vertex and fragment shaders, and that this value is
+ * at least 8.
+ */
+#include "piglit-util.h"
+
+int piglit_width = 100, piglit_height = 100;
+int piglit_window_mode = GLUT_RGB | GLUT_DOUBLE;
+
+static const char vert[] =
+	"#version 130\n"
+	"uniform int expected_value;\n"
+	"uniform bool test_distances;\n"
+	"uniform bool test_in_vs;\n"
+	"void main()\n"
+	"{\n"
+	"  gl_Position = gl_Vertex;\n"
+	"  if (test_in_vs) {\n"
+	"    int value = test_distances ? gl_MaxClipDistances\n"
+	"                               : gl_MaxClipPlanes;\n"
+        "    gl_FrontColor = (value == expected_value)\n"
+	"                  ? vec4(0.0, 1.0, 0.0, 1.0)\n"
+	"                  : vec4(1.0, 0.0, 0.0, 1.0);\n"
+	"  }\n"
+	"}\n";
+
+static const char frag[] =
+	"#version 130\n"
+	"uniform int expected_value;\n"
+	"uniform bool test_distances;\n"
+	"uniform bool test_in_vs;\n"
+	"void main()\n"
+	"{\n"
+	"  if (test_in_vs) {\n"
+	"    gl_FragColor = gl_Color;\n"
+	"  } else {\n"
+	"    int value = test_distances ? gl_MaxClipDistances\n"
+	"                               : gl_MaxClipPlanes;\n"
+        "    gl_FragColor = (value == expected_value)\n"
+	"                 ? vec4(0.0, 1.0, 0.0, 1.0)\n"
+	"                 : vec4(1.0, 0.0, 0.0, 1.0);\n"
+	"  }\n"
+	"}\n";
+
+GLuint prog;
+
+enum piglit_result
+piglit_display(void)
+{
+	GLint max_clip_planes, max_clip_distances, expected_value;
+	GLint test_distances, test_in_vs;
+	float green[] = { 0.0, 1.0, 0.0, 1.0 };
+	GLint loc;
+
+	enum piglit_result result = PIGLIT_PASS;
+	glGetIntegerv(GL_MAX_CLIP_PLANES, &max_clip_planes);
+	printf("GL_MAX_CLIP_PLANES = %d\n", max_clip_planes);
+	glGetIntegerv(GL_MAX_CLIP_DISTANCES, &max_clip_distances);
+	printf("GL_MAX_CLIP_DISTANCES = %d\n", max_clip_distances);
+	if (max_clip_planes != max_clip_distances) {
+		printf("GL_MAX_CLIP_PLANES != GL_MAX_CLIP_DISTANCES\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+	if (max_clip_distances < 8) {
+		printf("GL_MAX_CLIP_DISTANCES < 8\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	expected_value = max_clip_distances;
+	loc = piglit_GetUniformLocation(prog, "expected_value");
+	piglit_Uniform1i(loc, expected_value);
+
+	for (test_distances = 0; test_distances <= 1; ++test_distances) {
+		loc = piglit_GetUniformLocation(prog, "test_distances");
+		piglit_Uniform1i(loc, test_distances);
+		for (test_in_vs = 0; test_in_vs <= 1; ++test_in_vs) {
+			bool pass;
+			loc = piglit_GetUniformLocation(prog, "test_in_vs");
+			piglit_Uniform1i(loc, test_in_vs);
+			piglit_draw_rect(-1, -1, 2, 2);
+			pass = piglit_probe_rect_rgba(0, 0, piglit_width,
+						      piglit_height, green);
+			printf("Checking that gl_MaxClip%s == %d in %s: %s\n",
+			       test_distances ? "Distances" : "Planes",
+			       expected_value,
+			       test_in_vs ? "VS" : "FS",
+			       pass ? "pass" : "fail");
+			if (!pass) {
+				result = PIGLIT_FAIL;
+			}
+		}
+	}
+
+	return result;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	GLuint vs;
+	GLuint fs;
+
+	piglit_require_GLSL();
+	piglit_require_GLSL_version(130);
+	vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
+	fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
+	prog = piglit_CreateProgram();
+	piglit_AttachShader(prog, vs);
+	piglit_AttachShader(prog, fs);
+	piglit_LinkProgram(prog);
+	piglit_DeleteShader(vs);
+	piglit_DeleteShader(fs);
+	piglit_UseProgram(prog);
+}