GL_ARB_texture_multisample: Test using glClear with a ms render target

This creates a mulitsample texture and tries clearing it with glClear
via a framebuffer. One of the clears covers the entire texture and the
other is clipped to the right half of the texture using a scissor.

On the i965 driver the clear that covers the whole of the texture
wasn't working in Mesa before commit 765efeef883cdbb86e052acd887e0c3.

https://bugs.freedesktop.org/show_bug.cgi?id=79729

3 files changed, 226 insertions, 1 deletions

diff --git a/tests/all.py b/tests/all.py
index b9ce22624..6bce7ec4f 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -1732,7 +1732,8 @@ with profile.group_manager(
     g(['arb_texture_multisample-negative-max-samples'])
     g(['arb_texture_multisample-teximage-3d-multisample'])
     g(['arb_texture_multisample-teximage-2d-multisample'])
-    g(['arb_texture_multisample-sample-depth'])
+    g(['arb_texture_multisample-sample-depth']),
+    g(['arb_texture_multisample-clear'])
 
 samplers_atm = ['sampler2DMS', 'isampler2DMS', 'usampler2DMS',
                 'sampler2DMSArray', 'isampler2DMSArray', 'usampler2DMSArray']
diff --git a/tests/spec/arb_texture_multisample/CMakeLists.gl.txt b/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
index e1ff42f57..1872bfeb8 100644
--- a/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
+++ b/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
@@ -23,4 +23,5 @@ piglit_add_executable (arb_texture_multisample-sample-position sample-position.c
 piglit_add_executable (arb_texture_multisample-teximage-2d-multisample teximage-2d-multisample.c)
 piglit_add_executable (arb_texture_multisample-teximage-3d-multisample teximage-3d-multisample.c)
 piglit_add_executable (arb_texture_multisample-sample-depth sample-depth.c)
+piglit_add_executable (arb_texture_multisample-clear clear.c)
 # vim: ft=cmake:
diff --git a/tests/spec/arb_texture_multisample/clear.c b/tests/spec/arb_texture_multisample/clear.c
new file mode 100644
index 000000000..f7ec826c1
--- /dev/null
+++ b/tests/spec/arb_texture_multisample/clear.c
@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2014 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 clear.c
+ *
+ * A test of using glClear with a framebuffer bound to a multisample
+ * texture. An 8x8 multisample texture is created with 4 samples. The
+ * whole texture is cleared to red and then the right half of it is
+ * cleared to green using a scissor. The texture is then drawn at
+ * 16x16 so that every sample of every texel can be drawn using a
+ * special shader. The values are then compared to check that all of
+ * the samples are cleared.
+ */
+
+#define TEX_WIDTH 8
+#define TEX_HEIGHT 8
+#define TEX_SAMPLES 4
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 21;
+
+	config.window_visual = PIGLIT_GL_VISUAL_RGB | PIGLIT_GL_VISUAL_DOUBLE;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static const float red[4] = {1.0, 0.0, 0.0, 1.0};
+static const float green[4] = {0.0, 1.0, 0.0, 1.0};
+
+static GLuint
+create_texture(void)
+{
+	GLuint tex;
+
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
+	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE,
+				TEX_SAMPLES,
+				GL_RGBA,
+				TEX_WIDTH, TEX_HEIGHT,
+				GL_FALSE /* fixedsamplelocations */);
+
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		piglit_report_result(PIGLIT_FAIL);
+
+	return tex;
+}
+
+static void
+clear_texture(GLuint tex)
+{
+	GLuint fb;
+
+	glGenFramebuffers(1, &fb);
+	glBindFramebuffer(GL_FRAMEBUFFER, fb);
+	glFramebufferTexture2D(GL_FRAMEBUFFER,
+			       GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D_MULTISAMPLE,
+			       tex,
+			       0 /* layer */);
+	assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) ==
+	       GL_FRAMEBUFFER_COMPLETE);
+
+	/* Clear the entire texture to red */
+	glClearColor(1.0, 0.0, 0.0, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	/* Clear the right half to green */
+	glClearColor(0.0, 1.0, 0.0, 1.0);
+	glEnable(GL_SCISSOR_TEST);
+	glScissor(TEX_WIDTH / 2, 0, TEX_WIDTH / 2, TEX_HEIGHT);
+	glClear(GL_COLOR_BUFFER_BIT);
+	glDisable(GL_SCISSOR_TEST);
+
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	glDeleteFramebuffers(1, &fb);
+
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		piglit_report_result(PIGLIT_FAIL);
+}
+
+static void
+init_program(void)
+{
+	GLuint prog;
+	GLuint uniform;
+
+	static const char vs_source[] =
+		"#version 130\n"
+		"in vec2 piglit_vertex;\n"
+		"uniform vec2 fb_size;\n"
+		"out vec2 sample_coord;\n"
+		"\n"
+		"void main()\n"
+		"{\n"
+		"        gl_Position = vec4(piglit_vertex * 2.0 /\n"
+		"                           fb_size - 1.0,\n"
+		"                           0.0, 1.0);\n"
+		"        sample_coord = piglit_vertex;\n"
+		"}\n";
+	static const char fs_source[] =
+		"#version 130\n"
+		"#extension GL_ARB_texture_multisample : enable\n"
+		"uniform sampler2DMS tex;\n"
+		"in vec2 sample_coord;\n"
+		"\n"
+		"void main()\n"
+		"{\n"
+		"        ivec2 isample_coord = ivec2(sample_coord);\n"
+		"        ivec2 tex_coord = isample_coord / 2;\n"
+		"        int sample = ((isample_coord.x & 1) * 2 +\n"
+		"                      (isample_coord.y & 1));\n"
+		"        gl_FragColor = texelFetch(tex, tex_coord, sample);\n"
+		"}\n";
+
+	prog = piglit_build_simple_program(vs_source, fs_source);
+
+	glUseProgram(prog);
+
+	uniform = glGetUniformLocation(prog, "tex");
+	glUniform1i(uniform, 0);
+
+	uniform = glGetUniformLocation(prog, "fb_size");
+	glUniform2f(uniform, piglit_width, piglit_height);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	GLint maxColorTextureSamples;
+
+	piglit_require_extension("GL_ARB_texture_multisample");
+	piglit_require_extension("GL_ARB_framebuffer_object");
+	piglit_require_GLSL_version(130);
+
+	/* We need to support multisample textures with at least 4
+	 * samples */
+	glGetIntegerv(GL_MAX_COLOR_TEXTURE_SAMPLES, &maxColorTextureSamples);
+	if (maxColorTextureSamples < TEX_SAMPLES) {
+		printf("At least %i texture samples are required\n",
+		       TEX_SAMPLES);
+		piglit_report_result(PIGLIT_SKIP);
+	}
+
+	init_program();
+}
+
+static void
+draw_tex(GLuint tex)
+{
+	static const struct {
+		float x, y;
+	} attribs[] = {
+		{ 0.0f, 0.0f },
+		{ TEX_WIDTH * 2.0f, 0.0f },
+		{ 0.0f, TEX_HEIGHT * 2.0f },
+		{ TEX_WIDTH * 2, TEX_HEIGHT * 2.0f },
+	};
+
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
+
+	glEnableVertexAttribArray(PIGLIT_ATTRIB_POS);
+	glVertexAttribPointer(PIGLIT_ATTRIB_POS,
+			      2, /* size */
+			      GL_FLOAT,
+			      GL_FALSE, /* normalized */
+			      sizeof attribs[0],
+			      &attribs[0].x);
+
+	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+	glDisableVertexAttribArray(PIGLIT_ATTRIB_POS);
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = true;
+	GLuint tex;
+
+	tex = create_texture();
+
+	clear_texture(tex);
+
+	draw_tex(tex);
+
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
+
+	glDeleteTextures(1, &tex);
+
+	/* Left half is red */
+	pass &= piglit_probe_rect_rgb(0, 0, TEX_WIDTH, TEX_HEIGHT * 2, red);
+	/* Right half is green */
+	pass &= piglit_probe_rect_rgb(TEX_WIDTH, 0,
+				      TEX_WIDTH, TEX_HEIGHT * 2,
+				      green);
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}