Tests: add CMake option to run Cycles regression tests on GPU devices

CYCLES_TEST_DEVICES is a list of devices (CPU, CUDA, OPTIX, OPENCL). It is set
to CPU only by default.

Test output is now writen to build/tests/cycles/<device>, and the HTML report
has separate report pages for the different devices, with option to compare
between CPU and GPU renders.

Various GPU tests are still failing due to CPU/GPU differences, these are to be
fixed or blacklisted still.

Ref T82193

tests/python/modules/render_report.py

@@ -102,6 +102,7 @@ class Report:
     __slots__ = (
         'title',
         'output_dir',
+        'global_dir',
         'reference_dir',
         'idiff',
         'pixelated',
@@ -112,17 +113,24 @@ class Report:
         'failed_tests',
         'passed_tests',
         'compare_tests',
-        'compare_engines'
+        'compare_engine',
+        'device'
     )
 
-    def __init__(self, title, output_dir, idiff):
+    def __init__(self, title, output_dir, idiff, device=None):
         self.title = title
         self.output_dir = output_dir
+        self.global_dir = os.path.dirname(output_dir)
         self.reference_dir = 'reference_renders'
         self.idiff = idiff
-        self.compare_engines = None
+        self.compare_engine = None
         self.fail_threshold = 0.016
         self.fail_percent = 1
+        self.device = device
+
+        if device:
+            self.title = self._engine_title(title, device)
+            self.output_dir = self._engine_path(self.output_dir, device.lower())
 
         self.pixelated = False
         self.verbose = os.environ.get("BLENDER_VERBOSE") is not None
@@ -147,8 +155,8 @@ class Report:
     def set_reference_dir(self, reference_dir):
         self.reference_dir = reference_dir
 
-    def set_compare_engines(self, engine, other_engine):
-        self.compare_engines = (engine, other_engine)
+    def set_compare_engine(self, other_engine, other_device=None):
+        self.compare_engine = (other_engine, other_device)
 
     def run(self, dirpath, blender, arguments_cb, batch=False):
         # Run tests and output report.
@@ -156,7 +164,7 @@ class Report:
         ok = self._run_all_tests(dirname, dirpath, blender, arguments_cb, batch)
         self._write_data(dirname)
         self._write_html()
-        if self.compare_engines:
+        if self.compare_engine:
             self._write_html(comparison=True)
         return ok
 
@@ -171,7 +179,7 @@ class Report:
         filepath = os.path.join(outdir, "passed.data")
         pathlib.Path(filepath).write_text(self.passed_tests)
 
-        if self.compare_engines:
+        if self.compare_engine:
             filepath = os.path.join(outdir, "compare.data")
             pathlib.Path(filepath).write_text(self.compare_tests)
 
@@ -181,12 +189,26 @@ class Report:
         else:
             return """<li class="breadcrumb-item"><a href="%s">%s</a></li>""" % (href, title)
 
+    def _engine_title(self, engine, device):
+        if device:
+            return engine.title() + ' ' + device
+        else:
+            return engine.title()
+
+    def _engine_path(self, path, device):
+        if device:
+            return os.path.join(path, device.lower())
+        else:
+            return path
+
     def _navigation_html(self, comparison):
         html = """<nav aria-label="breadcrumb"><ol class="breadcrumb">"""
-        html += self._navigation_item("Test Reports", "../report.html", False)
+        base_path = os.path.relpath(self.global_dir, self.output_dir)
+        global_report_path = os.path.join(base_path, "report.html")
+        html += self._navigation_item("Test Reports", global_report_path, False)
         html += self._navigation_item(self.title, "report.html", not comparison)
-        if self.compare_engines:
-            compare_title = "Compare with %s" % self.compare_engines[1].capitalize()
+        if self.compare_engine:
+            compare_title = "Compare with %s" % self._engine_title(*self.compare_engine)
             html += self._navigation_item(compare_title, "compare.html", comparison)
         html += """</ol></nav>"""
 
@@ -233,8 +255,8 @@ class Report:
 
         if comparison:
             title = self.title + " Test Compare"
-            engine_self = self.compare_engines[0].capitalize()
-            engine_other = self.compare_engines[1].capitalize()
+            engine_self = self.title
+            engine_other = self._engine_title(*self.compare_engine)
             columns_html = "<tr><th>Name</th><th>%s</th><th>%s</th>" % (engine_self, engine_other)
         else:
             title = self.title + " Test Report"
@@ -300,9 +322,8 @@ class Report:
 
         # Update global report
         if not comparison:
-            global_output_dir = os.path.dirname(self.output_dir)
             global_failed = failed if not comparison else None
-            global_report.add(global_output_dir, "Render", self.title, filepath, global_failed)
+            global_report.add(self.global_dir, "Render", self.title, filepath, global_failed)
 
     def _relative_url(self, filepath):
         relpath = os.path.relpath(filepath, self.output_dir)
@@ -340,8 +361,9 @@ class Report:
         else:
             self.passed_tests += test_html
 
-        if self.compare_engines:
-            ref_url = os.path.join("..", self.compare_engines[1], new_url)
+        if self.compare_engine:
+            base_path = os.path.relpath(self.global_dir, self.output_dir)
+            ref_url = os.path.join(base_path, self._engine_path(*self.compare_engine), new_url)
 
             test_html = """
                 <tr{tr_style}>
@@ -445,6 +467,9 @@ class Report:
                 if not batch:
                     break
 
+            if self.device:
+                command.extend(['--', '--cycles-device', self.device])
+
             # Run process
             crash = False
             output = None