SiandClaude Opus 5
e2252ecd30
Lays a single picture from disk over its input: fitted, filled, stretched, left at its own size or tiled, centred or pinned to the top left corner, nudged by an offset and mixed in by its opacity. The file it needs is a new kind of param, Path, so the interface shows a chooser and the CLI takes a file name, both without knowing an overlay exists. Projects write it relative to their own folder, as they do a source, and Image::load can now hand back the alpha channel instead of flattening it onto white, so a cut-out PNG keeps its cut-out. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
46 lines
1.7 KiB
C++
46 lines
1.7 KiB
C++
#pragma once
|
|
|
|
#include <cstdint>
|
|
#include <mutex>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "core/effect.hpp"
|
|
|
|
namespace effector {
|
|
|
|
// Lays one picture from disk over its input: a logo, a texture, a frame. The
|
|
// overlay is fitted to the canvas in the chosen way, placed from the top left
|
|
// or from the centre, nudged by an offset and mixed in by its opacity. Like the
|
|
// blur it needs no source images of its own, so it can lead a chain; given
|
|
// sources it fills the canvas from a randomly chosen one first.
|
|
class OverlayEffect : public Effect {
|
|
public:
|
|
std::string name() const override { return "overlay"; }
|
|
std::string title() const override { return "Image overlay"; }
|
|
std::string description() const override {
|
|
return "Lays a single image from disk over its input, fitted to the canvas, centred or "
|
|
"not, nudged by an offset and mixed in by its opacity.";
|
|
}
|
|
const std::vector<ParamSpec>& params() const override;
|
|
bool needsSources() const override { return false; }
|
|
|
|
Image render(const std::vector<Image>& sources, int width, int height, Rng& rng,
|
|
const ParamValues& values) const override;
|
|
|
|
private:
|
|
// The same file is re-read on every param change otherwise, and a render is
|
|
// a keystroke away in the interface. Renders can overlap, so it is guarded.
|
|
// Returns the decoded file and its alpha, reading it only when the path
|
|
// differs from the one already held.
|
|
void loadOverlay(const std::string& path, Image& image,
|
|
std::vector<std::uint8_t>& alpha) const;
|
|
|
|
mutable std::mutex cacheMutex_;
|
|
mutable std::string cachedPath_;
|
|
mutable Image cached_;
|
|
mutable std::vector<std::uint8_t> cachedAlpha_;
|
|
};
|
|
|
|
} // namespace effector
|