Texture composition for text no longer on the render thread

tests/CMakeLists.txt

@@ -44,6 +44,7 @@ add_video_shader_test(RenderCadenceCompositorRuntimeLayerModelTests
 	"${SRC_DIR}/runtime/RuntimeLayerModel.cpp"
 	"${SRC_DIR}/runtime/RuntimeJson.cpp"
 	"${SRC_DIR}/runtime/RuntimeParameterUtils.cpp"
+	"${SRC_DIR}/runtime/RuntimeTextTextureComposer.cpp"
 	"${SRC_DIR}/runtime/SupportedShaderCatalog.cpp"
 	"${SRC_DIR}/shader/ShaderPackageRegistry.cpp"
 	"${TEST_DIR}/RenderCadenceCompositorRuntimeLayerModelTests.cpp"
@@ -79,6 +80,7 @@ add_video_shader_test(RenderCadenceCompositorRuntimeStateJsonTests
 	"${SRC_DIR}/runtime/RuntimeJson.cpp"
 	"${SRC_DIR}/runtime/RuntimeLayerModel.cpp"
 	"${SRC_DIR}/runtime/RuntimeParameterUtils.cpp"
+	"${SRC_DIR}/runtime/RuntimeTextTextureComposer.cpp"
 	"${SRC_DIR}/runtime/SupportedShaderCatalog.cpp"
 	"${SRC_DIR}/shader/ShaderPackageRegistry.cpp"
 	"${TEST_DIR}/RenderCadenceCompositorRuntimeStateJsonTests.cpp"

tests/RenderCadenceCompositorRuntimeLayerModelTests.cpp

@@ -94,6 +94,42 @@ RenderCadenceCompositor::SupportedShaderCatalog MakeCatalog(std::filesystem::pat
 	return LoadCatalog(root);
 }
 
+RenderCadenceCompositor::FontAtlasBuildOutput MakeFakeFontAtlas()
+{
+	RenderCadenceCompositor::FontAtlasBuildOutput atlas;
+	atlas.fontId = "inter";
+	atlas.width = 2;
+	atlas.height = 2;
+	atlas.ascender = -0.8;
+	atlas.rgbaPixels = {
+		255, 255, 255, 255,
+		255, 255, 255, 255,
+		255, 255, 255, 255,
+		255, 255, 255, 255
+	};
+
+	RenderCadenceCompositor::FontAtlasBuildOutput::Glyph glyph;
+	glyph.advance = 0.5;
+	glyph.planeLeft = 0.0;
+	glyph.planeTop = 0.0;
+	glyph.planeRight = 0.4;
+	glyph.planeBottom = 0.6;
+	glyph.atlasLeft = 0.0;
+	glyph.atlasTop = 0.0;
+	glyph.atlasRight = 1.0;
+	glyph.atlasBottom = 1.0;
+	glyph.hasBounds = true;
+	atlas.glyphsByCodepoint['A'] = glyph;
+	atlas.glyphsByCodepoint['B'] = glyph;
+	atlas.glyphsByCodepoint['D'] = glyph;
+	atlas.glyphsByCodepoint['E'] = glyph;
+	atlas.glyphsByCodepoint['F'] = glyph;
+	atlas.glyphsByCodepoint['L'] = glyph;
+	atlas.glyphsByCodepoint['T'] = glyph;
+	atlas.glyphsByCodepoint['U'] = glyph;
+	return atlas;
+}
+
 void TestSingleLayerLifecycle()
 {
 	std::filesystem::path root;
@@ -368,6 +404,46 @@ void TestReloadRefreshesChangedShaderMetadataAndPreservesValues()
 
 	std::filesystem::remove_all(root);
 }
+
+void TestTextTexturesArePreparedInRuntimeModel()
+{
+	std::filesystem::path root = MakeTestRoot();
+	WriteFile(root / "all-params" / "shader.slang", "float4 shadeVideo(float2 uv) { return float4(uv, 0.0, 1.0); }\n");
+	WriteFile(root / "all-params" / "Inter.ttf", "not a real font, but enough for catalog support checks");
+	WriteFile(root / "all-params" / "shader.json", AllParametersShaderManifest());
+	RenderCadenceCompositor::SupportedShaderCatalog catalog = LoadCatalog(root);
+
+	RenderCadenceCompositor::RuntimeLayerModel model;
+	std::string error;
+	Expect(model.InitializeSingleLayer(catalog, "all-params", error), "text layer can initialize");
+
+	RenderCadenceCompositor::RuntimeLayerModelSnapshot snapshot = model.Snapshot();
+	RuntimeShaderArtifact artifact;
+	artifact.layerId = model.FirstLayerId();
+	artifact.shaderId = "all-params";
+	artifact.displayName = "All Params";
+	artifact.fragmentShaderSource = "void main(){}";
+	artifact.parameterDefinitions = snapshot.displayLayers[0].parameterDefinitions;
+	artifact.fontAtlases.push_back(MakeFakeFontAtlas());
+	artifact.message = "build ready";
+	Expect(model.MarkBuildReady(artifact, error), error.empty() ? "ready text artifact prepares textures" : error);
+
+	snapshot = model.Snapshot();
+	Expect(snapshot.renderLayers.size() == 1, "text artifact is render-ready");
+	Expect(snapshot.renderLayers[0].artifact.preparedTextTextures.size() == 1, "render snapshot carries prepared text texture");
+	Expect(snapshot.renderLayers[0].artifact.fontAtlases.empty(), "render snapshot does not carry font atlas pixels");
+	const RuntimePreparedTextTexture preparedDefault = snapshot.renderLayers[0].artifact.preparedTextTextures[0];
+	Expect(preparedDefault.textValue == "DEFAULT", "default text is prepared");
+	Expect(preparedDefault.rgbaPixels && !preparedDefault.rgbaPixels->empty(), "prepared text has pixels");
+
+	Expect(model.UpdateParameter(model.FirstLayerId(), "titleText", JsonValue("AB"), error), error.empty() ? "text parameter update prepares texture" : error);
+	snapshot = model.Snapshot();
+	const RuntimePreparedTextTexture preparedUpdated = snapshot.renderLayers[0].artifact.preparedTextTextures[0];
+	Expect(preparedUpdated.textValue == "AB", "updated text is prepared before render snapshot");
+	Expect(preparedUpdated.rgbaPixels && preparedUpdated.rgbaPixels != preparedDefault.rgbaPixels, "updated text receives a new prepared pixel payload");
+
+	std::filesystem::remove_all(root);
+}
 }
 
 int main()
@@ -380,6 +456,7 @@ int main()
 	TestInvalidRuntimeStateCanFallBackToConfiguredShader();
 	TestLayerControlsUpdateDisplayAndRenderModels();
 	TestReloadRefreshesChangedShaderMetadataAndPreservesValues();
+	TestTextTexturesArePreparedInRuntimeModel();
 
 	if (gFailures != 0)
 	{