feat: add Ming-Image Design support (#2063)

src/runtime/denoiser.hpp

@@ -1369,6 +1369,42 @@ struct DiscreteFlowDenoiser : public Denoiser {
     }
 };
 
+struct MingImageFlowDenoiser : DiscreteFlowDenoiser {
+    float resolution_shift = std::exp(1.35f);
+
+    MingImageFlowDenoiser()
+        : DiscreteFlowDenoiser(INFINITY) {}
+
+    float sigma_min() override { return 0.f; }
+    float sigma_max() override { return 1.f; }
+
+    float t_to_sigma(float t) override {
+        return time_snr_shift(std::isfinite(shift) ? shift : resolution_shift, (t + 1.f) / 1000.f);
+    }
+
+    std::vector<float> get_sigmas(uint32_t n, int image_seq_len, scheduler_t scheduler, SDVersion version, const char* extra_sample_args = nullptr) override {
+        const float tokens = static_cast<float>(image_seq_len) / 4.f;
+        const float mu     = tokens >= 4096.f ? 1.35f : 0.5f + (tokens - 256.f) * (1.15f - 0.5f) / (4096.f - 256.f);
+        resolution_shift   = std::exp(mu);
+        if (scheduler != DISCRETE_SCHEDULER) {
+            return DiscreteFlowDenoiser::get_sigmas(n, image_seq_len, scheduler, version, extra_sample_args);
+        }
+        if (n == 0) {
+            return {};
+        }
+        const float factor = std::isfinite(shift) ? shift : resolution_shift;
+        std::vector<float> sigmas;
+        sigmas.reserve(n + 1);
+        for (uint32_t i = 0; i < n; ++i) {
+            const float t = n == 1 ? 1.f : 1.f - static_cast<float>(i) / static_cast<float>(n - 1);
+            sigmas.push_back(time_snr_shift(factor, t));
+        }
+        // Upstream sets sigma_min to zero before linspace, then appends the terminal zero.
+        sigmas.push_back(0.f);
+        return sigmas;
+    }
+};
+
 struct H3AVFlowDenoiser : public DiscreteFlowDenoiser {
     int64_t video_channels;
     float audio_shift;
@@ -1783,7 +1819,10 @@ static sd::Tensor<float> sample_euler(denoise_cb_t model,
                                       const std::vector<float>& sigmas) {
     int steps = static_cast<int>(sigmas.size()) - 1;
     for (int i = 0; i < steps; i++) {
-        float sigma       = sigmas[i];
+        float sigma = sigmas[i];
+        if (sigma == sigmas[i + 1]) {
+            continue;
+        }
         auto denoised_opt = model(x, sigma, i + 1);
         if (denoised_opt.pred.empty()) {
             return {};