arb_texture_barrier add test texture-halves-ping-pong-operation-chain

From the GL_ARB_texture_barrier spec:

 "Specifically, the values of rendered fragments are undefined if any
 shader stage fetches texels and the same texels are written via fragment
 shader outputs, even if the reads and writes are not in the same Draw
 call, unless any of the following exceptions apply:

 - The reads and writes are from/to disjoint sets of texels (after
   accounting for texture filtering rules).

 - There is only a single read and write of each texel, and the read is in
   the fragment shader invocation that writes the same texel (e.g. using
   "texelFetch2D(sampler, ivec2(gl_FragCoord.xy), 0);").

 - If a texel has been written, then in order to safely read the result
   a texel fetch must be in a subsequent Draw separated by the command

     void TextureBarrier(void);

   TextureBarrier() will guarantee that writes have completed and caches
   have been invalidated before subsequent Draws are executed."

Previously the only Piglit test for ARB_texture_barrier tested point 2 of
that statement. This test aims to test point 1.

It uses an uint texture bound as the colorbuffer and texture sampler
source. It renders 6 passes.
Every pass one half of the texture is sampled from while the other is
written to. Which is which is swapped every pass.
The operations in the passes are chosen so that the end result will differ
if any pass is missing or the passes aren't executed in the correct order.

Reviewed-by: Brian Paul <brianp@vmware.com>

3 files changed, 205 insertions, 0 deletions

diff --git a/tests/all.py b/tests/all.py
index 846942b33..cd16ce9f5 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -3848,6 +3848,7 @@ with profile.test_list.group_manager(
         PiglitGLTest,
         grouptools.join('spec', 'nv_texture_barrier')) as g:
     g(['blending-in-shader'], run_concurrent=False)
+    g(['arb_texture_barrier-texture-halves-ping-pong-operation-chain'])
 
 with profile.test_list.group_manager(
         PiglitGLTest,
diff --git a/tests/spec/arb_texture_barrier/CMakeLists.gl.txt b/tests/spec/arb_texture_barrier/CMakeLists.gl.txt
index 30578e821..dd091b56a 100644
--- a/tests/spec/arb_texture_barrier/CMakeLists.gl.txt
+++ b/tests/spec/arb_texture_barrier/CMakeLists.gl.txt
@@ -9,5 +9,6 @@ link_libraries (
 )
 
 piglit_add_executable (arb_texture_barrier-blending-in-shader blending-in-shader-arb.c)
+piglit_add_executable (arb_texture_barrier-texture-halves-ping-pong-operation-chain texture-halves-ping-pong-operation-chain.c)
 
 # vim: ft=cmake:
diff --git a/tests/spec/arb_texture_barrier/texture-halves-ping-pong-operation-chain.c b/tests/spec/arb_texture_barrier/texture-halves-ping-pong-operation-chain.c
new file mode 100644
index 000000000..213059124
--- /dev/null
+++ b/tests/spec/arb_texture_barrier/texture-halves-ping-pong-operation-chain.c
@@ -0,0 +1,203 @@
+/*
+ * 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 texture-halves-ping-pong-operation-chain.c
+ *
+ * From the GL_ARB_texture_barrier spec:
+ *
+ *  "Specifically, the values of rendered fragments are undefined if any
+ *  shader stage fetches texels and the same texels are written via fragment
+ *  shader outputs, even if the reads and writes are not in the same Draw
+ *  call, unless any of the following exceptions apply:
+ *
+ *  - The reads and writes are from/to disjoint sets of texels (after
+ *    accounting for texture filtering rules).
+ *
+ *  - There is only a single read and write of each texel, and the read is in
+ *    the fragment shader invocation that writes the same texel (e.g. using
+ *    "texelFetch2D(sampler, ivec2(gl_FragCoord.xy), 0);").
+ *
+ *  - If a texel has been written, then in order to safely read the result
+ *    a texel fetch must be in a subsequent Draw separated by the command
+ *
+ *      void TextureBarrier(void);
+ *
+ *    TextureBarrier() will guarantee that writes have completed and caches
+ *    have been invalidated before subsequent Draws are executed."
+ *
+ * This test aims to test points 1 and 3 of that statement.
+ *
+ * It uses an uint texture bound as the colorbuffer and texture sampler
+ * source. It renders 6 passes.
+ * Every pass one half of the texture is sampled from while the other is
+ * written to. Which is which is swapped every pass.
+ * The operations in the passes are chosen so that the end result will differ
+ * if any pass is missing or the passes aren't executed in the correct order.
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 31;
+	config.supports_gl_core_version = 31;
+	config.window_visual = PIGLIT_GL_VISUAL_RGB;
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static unsigned tex, render_pass_loc;
+
+static int width;
+static int height;
+
+static const char *vs_text =
+	"#version 130\n"
+	"in vec4 piglit_vertex;"
+	"void main() {\n"
+	"	gl_Position = piglit_vertex;\n"
+	"}\n";
+
+static const char *fs_text =
+	"#version 130\n"
+	"uniform int render_pass;\n"
+	"uniform usampler2D fb;\n"
+	"out uvec4 color;\n"
+	"void main() {\n"
+	"	int x_ofs = textureSize(fb, 0).x / 2;\n"
+	"	x_ofs *= render_pass % 2 != 0 ? -1 : 1;\n"
+	"	ivec2 tex_coord = ivec2(gl_FragCoord.xy) + ivec2(x_ofs, 0);\n"
+	"	uvec4 prev_color = texelFetch(fb, tex_coord, 0);\n"
+	"	switch (render_pass) {\n"
+	"	case 0:\n"
+	"		color = uvec4(1);\n"
+	"		break;\n"
+	"	case 1:\n"
+	"		color = prev_color * 2u;\n"
+	"		break;\n"
+	"	case 2:\n"
+	"		color = prev_color + 2u;\n"
+	"		break;\n"
+	"	case 3:\n"
+	"		color = prev_color ^ 1023u;\n"
+	"		break;\n"
+	"	case 4:\n"
+	"		color = prev_color << 2u;\n"
+	"		break;\n"
+	"	case 5:\n"
+	"		color = prev_color % 32u;\n"
+	"		break;\n"
+	"	}\n"
+	"}\n";
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = true;
+
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	for (int i = 0; true; ++i) {
+		glUniform1i(render_pass_loc, i);
+		if (i%2)
+			piglit_draw_rect(0, -1, 1, 2);
+		else
+			piglit_draw_rect(-1, -1, 1, 2);
+		if (i >= 5)
+			break;
+		glTextureBarrier();
+	}
+
+	unsigned color = 1;
+	color *= 2;
+	color += 2;
+	color ^= 1023;
+	color <<= 2;
+	const unsigned expected_left[] = { color, 0, 0, 1 };
+	color %= 32;
+	const unsigned expected_right[] = { color, 0, 0, 1 };
+	pass = piglit_probe_rect_rgba_uint(0, 0, width / 2, height,
+					   expected_left) && pass;
+	pass = piglit_probe_rect_rgba_uint(width / 2, 0, width / 2, height,
+					   expected_right) && pass;
+
+	pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+static void
+initialize_texture()
+{
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D, tex);
+	glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32UI, width, height);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+}
+
+static void
+initialize_fbo()
+{
+	unsigned fbo;
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+	glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, tex, 0);
+	assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) ==
+	       GL_FRAMEBUFFER_COMPLETE);
+}
+
+static void
+initialize_program()
+{
+	unsigned prog;
+	prog = piglit_build_simple_program(vs_text, fs_text);
+	glUseProgram(prog);
+
+	render_pass_loc = glGetUniformLocation(prog, "render_pass");
+	if (render_pass_loc == -1) {
+		fprintf(stderr, "Error getting uniform render_pass.\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	int fb_loc = glGetUniformLocation(prog, "fb");
+	glUniform1i(fb_loc, 0);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_ARB_framebuffer_object");
+	piglit_require_extension("GL_ARB_texture_barrier");
+	piglit_require_GLSL_version(130);
+
+	width = 256;
+	height = 128;
+
+	initialize_program();
+	initialize_texture();
+	initialize_fbo();
+
+	glViewport(0, 0, width, height);
+}