Function build_overlay

examples/main_image.cpp:171–207

}

static void build_overlay(app_state& app) {
    if (app.image.data.empty()) return;
    int w = app.image.width;
    int h = app.image.height;

    std::vector<uint8_t> overlay(w * h * 4);
    for (int i = 0; i < w * h; ++i) {
        overlay[4*i+0] = app.image.data[3*i+0];
        overlay[4*i+1] = app.image.data[3*i+1];
        overlay[4*i+2] = app.image.data[3*i+2];
        overlay[4*i+3] = 255;
    }

    if (app.show_masks) {
        for (size_t d = 0; d < app.result.detections.size(); ++d) {
            const auto& det = app.result.detections[d];
            if (det.mask.data.empty()) continue;
            const float* c = INSTANCE_COLORS[d % N_COLORS];
            float alpha = 0.4f;

            int mw = det.mask.width;
            int mh = det.mask.height;
            for (int y = 0; y < std::min(h, mh); ++y) {
                for (int x = 0; x < std::min(w, mw); ++x) {
                    if (det.mask.data[y * mw + x] > 127) {
                        int idx = (y * w + x) * 4;
                        overlay[idx+0] = (uint8_t)(overlay[idx+0] * (1-alpha) + c[0]*255*alpha);
                        overlay[idx+1] = (uint8_t)(overlay[idx+1] * (1-alpha) + c[1]*255*alpha);
                        overlay[idx+2] = (uint8_t)(overlay[idx+2] * (1-alpha) + c[2]*255*alpha);
                    }
                }
            }
        }
    }

    app.tex_overlay = upload_texture(overlay.data(), w, h, 4, app.tex_overlay);
}

static void load_image(app_state& app, const char* path) {
    snprintf(app.status, sizeof(app.status), "Loading image: %s", path);