fbo: add a few quirk-tests for format-emulation

Drivers who implement GL_ALPHA textures by swizzling a GL_R texture
needs to be prepared to offer multiple blend-colors, otherwise they
will produce the wrong result, because the blend-color will also
need per-format swizzling.

Similarly, when drivers implement GL_RGB with GL_RGBA and adjust the
blend-factors, they need to have separate blend-factors for all
framebuffer attachments or the results will be wrong.

This reveals a couple of bugs in virgl, where these currently fail.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

3 files changed, 178 insertions, 0 deletions

diff --git a/tests/fbo/CMakeLists.gl.txt b/tests/fbo/CMakeLists.gl.txt
index d594c24d3..1a1a60765 100644
--- a/tests/fbo/CMakeLists.gl.txt
+++ b/tests/fbo/CMakeLists.gl.txt
@@ -29,6 +29,7 @@ piglit_add_executable (fbo-blit fbo-blit.c)
 piglit_add_executable (fbo-blit-d24s8 fbo-blit-d24s8.c)
 piglit_add_executable (fbo-blit-stretch fbo-blit-stretch.cpp)
 piglit_add_executable (fbo-blending-formats fbo-blending-formats.c)
+piglit_add_executable (fbo-blending-format-quirks fbo-blending-format-quirks.c)
 piglit_add_executable (fbo-blending-snorm fbo-blending-snorm.c)
 piglit_add_executable (fbo-colormask-formats fbo-colormask-formats.c)
 piglit_add_executable (fbo-copypix fbo-copypix.c)
diff --git a/tests/fbo/fbo-blending-format-quirks.c b/tests/fbo/fbo-blending-format-quirks.c
new file mode 100644
index 000000000..1b71b3252
--- /dev/null
+++ b/tests/fbo/fbo-blending-format-quirks.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright © 2018 Collabora Ltd
+ *
+ * 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.
+ *
+ * Authors:
+ *    Erik Faye-Lund <erik.faye-lund@collabora.com>
+ *
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 10;
+
+	/* Drivers that do not support GL_ARB_texture_non_power_of_two require
+	 * window dimensions that are powers of two for this test.
+	 */
+	config.window_width = next_power_of_two(config.window_width);
+	config.window_height = next_power_of_two(config.window_height);
+
+	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static enum piglit_result test_formats(const char *name, GLenum formats[2],
+				       float expect[2][4], GLenum factors[2])
+{
+	GLboolean pass = GL_TRUE;
+	GLuint tex[2], fb;
+	GLenum draw_bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
+	GLenum status;
+	int i;
+
+	glGenFramebuffersEXT(1, &fb);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
+	glViewport(0, 0, piglit_width, piglit_height);
+
+	glGenTextures(2, tex);
+	for (i = 0; i < 2; ++i) {
+		glBindTexture(GL_TEXTURE_2D, tex[i]);
+		glTexImage2D(GL_TEXTURE_2D, 0, formats[i],
+			     piglit_width, piglit_height, 0,
+			     GL_RGBA, GL_FLOAT, NULL);
+
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
+					  GL_COLOR_ATTACHMENT0_EXT + i,
+					  GL_TEXTURE_2D,
+					  tex[i],
+					  0);
+	}
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		piglit_report_result(PIGLIT_FAIL);
+
+	status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+	if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+		printf(" - fbo incomplete (status = %s)\n",
+		       piglit_get_gl_enum_name(status));
+		return PIGLIT_SKIP;
+	}
+
+	printf("Testing %s\n", name);
+
+	glClearColor(0.0, 0.0, 0.0, 0.5);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	glEnable(GL_BLEND);
+	glBlendFunc(factors[0], factors[1]);
+	glBlendColor(1.0, 0.5, 0.25, 0.125);
+	glColor4f(1.0, 1.0, 1.0, 1.0);
+
+	glDrawBuffers(2, draw_bufs);
+	piglit_draw_rect(-1.0, -1.0, 2.0, 2.0);
+
+	glReadBuffer(GL_COLOR_ATTACHMENT0);
+	if (!piglit_probe_pixel_rgba(piglit_width / 2, piglit_height / 2,
+				     expect[0])) {
+		printf("  when testing GL_COLOR_ATTACHMENT0.\n");
+		pass = GL_FALSE;
+	}
+
+	glReadBuffer(GL_COLOR_ATTACHMENT1);
+	if (!piglit_probe_pixel_rgba(piglit_width / 2, piglit_height / 2,
+				     expect[1])) {
+		printf("  when testing GL_COLOR_ATTACHMENT1.\n");
+		pass = GL_FALSE;
+	}
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+enum piglit_result piglit_display(void)
+{
+	int i;
+        enum piglit_result result, end_result = PIGLIT_PASS;
+        bool all_skip = true;
+
+	static const struct {
+		const char *name;
+		GLenum formats[2];
+		GLenum factors[2];
+		float expect[2][4];
+	} cases[] = {
+		{ "alpha expand",
+			{ GL_RGBA, GL_RGB },
+			{ GL_DST_ALPHA, GL_ZERO }, {
+				{ 0.5, 0.5, 0.5, 0.5 },
+				{ 1.0, 1.0, 1.0, 1.0 }
+			}
+		},
+
+		{ "alpha swizzle, variant 1",
+			{ GL_RGBA, GL_ALPHA },
+			{ GL_DST_ALPHA, GL_ZERO }, {
+				{ 0.5, 0.5, 0.5, 0.5 },
+				{ 0.0, 0.0, 0.0, 0.0 }
+			}
+		},
+
+		{ "alpha swizzle, variant 2",
+			{ GL_RGBA, GL_ALPHA },
+			{ GL_CONSTANT_COLOR, GL_ZERO }, {
+				{ 1.0, 0.5, 0.25, 0.125 },
+				{ 0.0, 0.0, 0.0, 0.125 }
+			}
+		},
+
+		{ "alpha swizzle, variant 3",
+			{ GL_ALPHA, GL_RGBA },
+			{ GL_CONSTANT_COLOR, GL_ZERO }, {
+				{ 0.0, 0.0, 0.0, 0.125 },
+				{ 1.0, 0.5, 0.25, 0.125 }
+			}
+		}
+	};
+
+	for (i = 0; i < ARRAY_SIZE(cases); ++i) {
+		result = test_formats(cases[i].name, cases[i].formats,
+				      cases[i].expect, cases[i].factors);
+
+		if (result != PIGLIT_SKIP)
+			all_skip = false;
+
+		if (result == PIGLIT_FAIL)
+			end_result = result;
+	}
+
+	if (all_skip)
+		return PIGLIT_SKIP;
+	return end_result;
+}
+
+void piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_EXT_framebuffer_object");
+	glDisable(GL_DITHER);
+}
diff --git a/tests/opengl.py b/tests/opengl.py
index f7e408cd5..54cfd04d5 100644
--- a/tests/opengl.py
+++ b/tests/opengl.py
@@ -2955,6 +2955,7 @@ with profile.test_list.group_manager(
     g(['fbo-alphatest-nocolor'])
     g(['fbo-alphatest-nocolor-ff'])
     g(['fbo-blending-formats'])
+    g(['fbo-blending-format-quirks'])
     g(['fbo-blending-snorm'])
     g(['fbo-bind-renderbuffer'])
     g(['fbo-clearmipmap'])