[Piglit] [PATCH 04/23] Add linear fog GLSL test.

[Fabian Bieler]

This aimes to replace and extend a subtest of the Glean glsl test.
---
 tests/all.py                                     |  1 +
 tests/spec/glsl-1.10/execution/CMakeLists.gl.txt |  1 +
 tests/spec/glsl-1.10/execution/linear-fog.c      | 96 ++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 tests/spec/glsl-1.10/execution/linear-fog.c

diff --git a/tests/all.py b/tests/all.py
index 8e80a61..e0f327e 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -1422,6 +1422,7 @@ with profile.test_list.group_manager(
     g(['glsl-1.10-built-in-matrix-state'])
     g(['glsl-1.10-built-in-uniform-state'])
     g(['glsl-1.10-fragdepth'])
+    g(['glsl-1.10-linear-fog'])
 
 with profile.test_list.group_manager(
         PiglitGLTest,
diff --git a/tests/spec/glsl-1.10/execution/CMakeLists.gl.txt b/tests/spec/glsl-1.10/execution/CMakeLists.gl.txt
index 3303f47..18c98f9 100644
--- a/tests/spec/glsl-1.10/execution/CMakeLists.gl.txt
+++ b/tests/spec/glsl-1.10/execution/CMakeLists.gl.txt
@@ -14,3 +14,4 @@ piglit_add_executable (glsl-render-after-bad-attach glsl-render-after-bad-attach
 piglit_add_executable (glsl-1.10-built-in-matrix-state built-in-matrix-state.c)
 piglit_add_executable (glsl-1.10-built-in-uniform-state built-in-uniform-state.c)
 piglit_add_executable (glsl-1.10-fragdepth fragdepth.c)
+piglit_add_executable (glsl-1.10-linear-fog linear-fog.c)
diff --git a/tests/spec/glsl-1.10/execution/linear-fog.c b/tests/spec/glsl-1.10/execution/linear-fog.c
new file mode 100644
index 0000000..88d659a
--- /dev/null
+++ b/tests/spec/glsl-1.10/execution/linear-fog.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2017 Fabian Bieler
+ *
+ * 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 linear-fog.c:  Draw using linear fog in GLSL.
+ *
+ * Simple fog test with constant fog coordinates.
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 20;
+	config.window_visual = (PIGLIT_GL_VISUAL_RGBA);
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static const char *vs_text =
+	"void main() {\n"
+	"   gl_Position = gl_Vertex; \n"
+	"   gl_FogFragCoord = gl_MultiTexCoord0.x; \n"
+	"   gl_FrontColor = gl_Color; \n"
+	"}\n";
+static const char *fs_text =
+	"void main() {\n"
+	"   float bf = (gl_FogFragCoord - gl_Fog.start) * gl_Fog.scale; \n"
+	"   gl_FragColor = mix(gl_Color, gl_Fog.color, bf); \n"
+	"}\n";
+
+static const float vertex_color[] = {.25, .5, .75, .25};
+static const float fog_color[] = {1, .5, 1, 0};
+static const float fog_start = 100;
+static const float fog_end = 200;
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = true;
+
+	for (int j = 0; j < 5; ++j) {
+		const float fog_coord = 100 + j * 25;
+		const float bf =
+			(fog_coord - fog_start) / (fog_end - fog_start);
+		float expected_color[4];
+		for (int i = 0; i < 4; ++i)
+			expected_color[i] = bf * fog_color[i] +
+					    (1 - bf) * vertex_color[i];
+
+		glClear(GL_COLOR_BUFFER_BIT);
+
+		glTexCoord1f(fog_coord);
+		piglit_draw_rect(-1, -1, 2, 2);
+
+		pass = piglit_probe_pixel_rgba(piglit_width / 2,
+					       piglit_height / 2,
+					       expected_color) &&
+		       pass;
+	}
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	const int program = piglit_build_simple_program(vs_text, fs_text);
+
+	glUseProgram(program);
+
+	glColor4fv(vertex_color);
+	glFogf(GL_FOG_START, fog_start);
+	glFogf(GL_FOG_END, fog_end);
+	glFogfv(GL_FOG_COLOR, fog_color);
+}
-- 
2.7.4