Simulate strokes from pano cli

docs/modernization/build-inventory.md

@@ -98,6 +98,8 @@ Known local toolchain state:
   `pano_cli_inspect_png_metadata_smoke` with a tiny IHDR fixture.
 - `pano_cli create-document` supports `--frames` and `--frame-duration-ms` and
   is covered by `pano_cli_create_animation_document_smoke`.
+- `pano_cli simulate-stroke` exposes the pure stroke sampler for scripted
+  automation and is covered by `pano_cli_simulate_stroke_smoke`.
 - `panopainter_validate_shaders` validates the current combined GLSL shader
   files for one vertex stage marker, one fragment stage marker, valid marker
   order, and existing relative includes.

docs/modernization/roadmap.md

@@ -328,9 +328,10 @@ length parsing, color parsing, tinyxml-backed layout XML parsing, and invalid
 input tests.
 `pano_cli inspect-image` exposes PNG IHDR metadata as JSON, and
 `pano_cli create-document` can create simple animation documents with explicit
-frame count/duration. `pano_cli parse-layout` exercises the XML layout path.
-Continue expanding document behavior toward legacy Canvas parity and then port
-OpenGL classes behind the renderer boundary.
+frame count/duration, and `pano_cli simulate-stroke` exercises the pure stroke
+sampler for scripted-stroke automation. `pano_cli parse-layout` exercises the
+XML layout path. Continue expanding document behavior toward legacy Canvas
+parity and then port OpenGL classes behind the renderer boundary.
 
 Implementation tasks:
 
@@ -582,6 +583,8 @@ Results:
 - `pano_cli_inspect_png_metadata_smoke` passed and reports PNG metadata JSON
   for the tiny IHDR fixture.
 - `pano_cli_parse_layout_smoke` passed.
+- `pano_cli_simulate_stroke_smoke` passed and reports deterministic stroke
+  sample counts/distances.
 - `panopainter_validate_shaders` passed, validating 25 shader programs and 7
   shader includes for stage markers and include graph integrity.
 - PowerShell analyze automation returns JSON summaries and includes the shader

tests/CMakeLists.txt

@@ -224,4 +224,10 @@ if(TARGET pano_cli)
         COMMAND pano_cli parse-layout --path "${CMAKE_CURRENT_SOURCE_DIR}/data/layouts/simple-layout.xml")
     set_tests_properties(pano_cli_parse_layout_smoke PROPERTIES
         LABELS "ui;integration;desktop-fast")
+
+    add_test(NAME pano_cli_simulate_stroke_smoke
+        COMMAND pano_cli simulate-stroke --x1 0 --y1 0 --x2 10 --y2 0 --spacing 2)
+    set_tests_properties(pano_cli_simulate_stroke_smoke PROPERTIES
+        LABELS "paint;integration;desktop-fast"
+        PASS_REGULAR_EXPRESSION "\"samples\":6.*\"distance\":10")
 endif()

tools/pano_cli/main.cpp

@@ -4,6 +4,7 @@
 #include "document/document.h"
 #include "foundation/parse.h"
 #include "foundation/result.h"
+#include "paint/stroke.h"
 #include "ui_core/layout_xml.h"
 
 #include <cstdint>
@@ -37,6 +38,14 @@ struct InspectProjectArgs {
     std::string path;
 };
 
+struct SimulateStrokeArgs {
+    std::uint32_t x1 = 0;
+    std::uint32_t y1 = 0;
+    std::uint32_t x2 = 0;
+    std::uint32_t y2 = 0;
+    std::uint32_t spacing = 1;
+};
+
 void print_error(std::string_view command, std::string_view message)
 {
     std::cout << "{\"ok\":false,\"command\":\"" << command
@@ -51,6 +60,7 @@ void print_help()
         << "  inspect-image --path FILE\n"
         << "  inspect-project --path FILE\n"
         << "  parse-layout --path FILE\n"
+        << "  simulate-stroke --x1 N --y1 N --x2 N --y2 N [--spacing N]\n"
         << "  --help\n";
 }
 
@@ -291,6 +301,84 @@ int inspect_project(int argc, char** argv)
     return 0;
 }
 
+pp::foundation::Status parse_simulate_stroke_args(int argc, char** argv, SimulateStrokeArgs& args)
+{
+    for (int i = 2; i < argc; ++i) {
+        const std::string_view key(argv[i]);
+        if (key == "--x1" || key == "--y1" || key == "--x2" || key == "--y2" || key == "--spacing") {
+            if (i + 1 >= argc) {
+                return pp::foundation::Status::invalid_argument("missing value for option");
+            }
+
+            const auto value = pp::foundation::parse_u32(argv[++i]);
+            if (!value) {
+                return value.status();
+            }
+
+            if (key == "--x1") {
+                args.x1 = value.value();
+            } else if (key == "--y1") {
+                args.y1 = value.value();
+            } else if (key == "--x2") {
+                args.x2 = value.value();
+            } else if (key == "--y2") {
+                args.y2 = value.value();
+            } else {
+                args.spacing = value.value();
+            }
+        } else {
+            return pp::foundation::Status::invalid_argument("unknown option");
+        }
+    }
+
+    if (args.spacing == 0) {
+        return pp::foundation::Status::invalid_argument("stroke spacing must be greater than zero");
+    }
+
+    return pp::foundation::Status::success();
+}
+
+int simulate_stroke(int argc, char** argv)
+{
+    SimulateStrokeArgs args;
+    const auto status = parse_simulate_stroke_args(argc, argv, args);
+    if (!status.ok()) {
+        print_error("simulate-stroke", status.message);
+        return 2;
+    }
+
+    const pp::paint::StrokePoint points[] {
+        pp::paint::StrokePoint {
+            .x = static_cast<float>(args.x1),
+            .y = static_cast<float>(args.y1),
+            .pressure = 1.0F,
+        },
+        pp::paint::StrokePoint {
+            .x = static_cast<float>(args.x2),
+            .y = static_cast<float>(args.y2),
+            .pressure = 1.0F,
+        },
+    };
+    const auto samples = pp::paint::sample_stroke(
+        points,
+        pp::paint::StrokeSamplingConfig {
+            .spacing = static_cast<float>(args.spacing),
+        });
+    if (!samples) {
+        print_error("simulate-stroke", samples.status().message);
+        return 2;
+    }
+
+    const auto& first = samples.value().front();
+    const auto& last = samples.value().back();
+    std::cout << "{\"ok\":true,\"command\":\"simulate-stroke\""
+              << ",\"samples\":" << samples.value().size()
+              << ",\"first\":{\"x\":" << first.x << ",\"y\":" << first.y << "}"
+              << ",\"last\":{\"x\":" << last.x << ",\"y\":" << last.y
+              << ",\"distance\":" << last.distance << "}}\n";
+    return 0;
+}
+
 pp::foundation::Status parse_layout_args(int argc, char** argv, ParseLayoutArgs& args)
 {
     for (int i = 2; i < argc; ++i) {
@@ -372,6 +460,10 @@ int main(int argc, char** argv)
         return inspect_project(argc, argv);
     }
 
+    if (command == "simulate-stroke") {
+        return simulate_stroke(argc, argv);
+    }
+
     if (command == "parse-layout") {
         return parse_layout(argc, argv);
     }