Custom shaders: Clear cached programs when disabling shaders

docs/changelog.rst

@@ -206,7 +206,7 @@ Detailed list of changes
 
 - Custom shaders: Allow tinting inactive windows toward a configurable color,
   preserving the tab bar and active window padding. Support static effects
-  without periodic redraws.
+  without periodic redraws, and fix re-enabling a previously disabled shader.
 
 - Various throughput performance improvements for a 15-35% real world improvement depending on workload
 

kitty/shaders/slang.py

@@ -274,6 +274,7 @@ class LoadShaderPrograms:
             slot_pipelines = pmap.get(slot)
             if not slot_pipelines:
                 compile_program(prog, (), (), {}, allow_recompile)
+                self.last_built_custom_shaders.pop(prog, None)
             else:
                 try:
                     pipeline = merge_pipelines(slot_pipelines)
@@ -283,6 +284,7 @@ class LoadShaderPrograms:
                 except Exception as e:
                     log_error(f'Failed to build custom shader for slot {slot} with error: {e}')
                     compile_program(prog, (), (), {}, allow_recompile)
+                    self.last_built_custom_shaders.pop(prog, None)
                 else:
                     try:
                         if self.last_built_custom_shaders.get(prog) != (vert, frag, metadata):
@@ -291,6 +293,7 @@ class LoadShaderPrograms:
                     except Exception as e:
                         log_error(f'Failed to load custom shader for slot {slot} with error: {e}')
                         compile_program(prog, (), (), {}, allow_recompile)
+                        self.last_built_custom_shaders.pop(prog, None)
 
         do(CUSTOM_END_PROGRAM, 'end')
         compile_program(-2, (), (), {})  # initialize programs

kitty_tests/slang.py

@@ -8,10 +8,12 @@ import os
 import shutil
 import subprocess
 import tempfile
+from unittest.mock import patch
 
 from kitty.constants import slangc
 from kitty.shaders.slang import (
     EntryPoint,
+    LoadShaderPrograms,
     SlangFile,
     Stage,
     build_custom_shader_pipeline_glsl,
@@ -62,6 +64,25 @@ class TestSlang(BaseTest):
         self.assertTrue(fragment)
         self.ae(metadata['pipeline']['groups'][0]['animation_step'], 0)
 
+    def test_custom_shader_reenable(self):
+        from kitty.fast_data_types import CUSTOM_END_PROGRAM
+        from kitty.options.types import defaults
+
+        loader = LoadShaderPrograms()
+        loader.last_built_custom_shaders = {}
+        pipeline = parse_pipeline_definition(['startgroup', 'animation_step 0', 'shaders focus-highlight', 'endgroup'], 'test')
+        self.ae(pipeline['groups'][0]['animation_step'], 0)
+        with (
+            patch('kitty.shaders.slang.parse_pipeline', return_value=pipeline),
+            patch('kitty.shaders.slang.build_custom_shader_pipeline_glsl', return_value=('vertex', 'fragment', {})),
+            patch('kitty.shaders.slang.compile_program') as compile_program,
+        ):
+            for shaders in (('test',), (), ('test',)):
+                loader.opts = defaults._replace(custom_shaders=shaders)
+                loader.compile_custom_shaders(allow_recompile=True)
+            operations = [c.args[1] for c in compile_program.call_args_list if c.args[0] == CUSTOM_END_PROGRAM]
+            self.ae(operations, [('vertex',), (), ('vertex',)])
+
     def test_slang_parser(self):
         def check(src: str, expected: SlangFile) -> None:
             actual = parse_slang_text(src)