1 files changed, 94 insertions, 0 deletions
diff --git a/src/audio_core/renderer/command/mix/mix_ramp.cpp b/src/audio_core/renderer/command/mix/mix_ramp.cpp
new file mode 100644
index 000000000..ffdafa1c8
--- /dev/null
+++ b/src/audio_core/renderer/command/mix/mix_ramp.cpp
@@ -0,0 +1,94 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "audio_core/renderer/adsp/command_list_processor.h"
+#include "audio_core/renderer/command/mix/mix_ramp.h"
+#include "common/fixed_point.h"
+#include "common/logging/log.h"
+
+namespace AudioCore::AudioRenderer {
+/**
+ * Mix input mix buffer into output mix buffer, with volume applied to the input.
+ *
+ * @tparam Q           - Number of bits for fixed point operations.
+ * @param output       - Output mix buffer.
+ * @param input        - Input mix buffer.
+ * @param volume       - Volume applied to the input.
+ * @param ramp         - Ramp applied to volume every sample.
+ * @param sample_count - Number of samples to process.
+ * @return The final gained input sample, used for depopping.
+ */
+template <size_t Q>
+s32 ApplyMixRamp(std::span<s32> output, std::span<const s32> input, const f32 volume_,
+                 const f32 ramp_, const u32 sample_count) {
+    Common::FixedPoint<64 - Q, Q> volume{volume_};
+    Common::FixedPoint<64 - Q, Q> sample{0};
+
+    if (ramp_ == 0.0f) {
+        for (u32 i = 0; i < sample_count; i++) {
+            sample = input[i] * volume;
+            output[i] = (output[i] + sample).to_int();
+        }
+    } else {
+        Common::FixedPoint<64 - Q, Q> ramp{ramp_};
+        for (u32 i = 0; i < sample_count; i++) {
+            sample = input[i] * volume;
+            output[i] = (output[i] + sample).to_int();
+            volume += ramp;
+        }
+    }
+    return sample.to_int();
+}
+
+template s32 ApplyMixRamp<15>(std::span<s32>, std::span<const s32>, const f32, const f32,
+                              const u32);
+template s32 ApplyMixRamp<23>(std::span<s32>, std::span<const s32>, const f32, const f32,
+                              const u32);
+
+void MixRampCommand::Dump(const ADSP::CommandListProcessor& processor, std::string& string) {
+    const auto ramp{(volume - prev_volume) / static_cast<f32>(processor.sample_count)};
+    string += fmt::format("MixRampCommand");
+    string += fmt::format("\n\tinput {:02X}", input_index);
+    string += fmt::format("\n\toutput {:02X}", output_index);
+    string += fmt::format("\n\tvolume {:.8f}", volume);
+    string += fmt::format("\n\tprev_volume {:.8f}", prev_volume);
+    string += fmt::format("\n\tramp {:.8f}", ramp);
+    string += "\n";
+}
+
+void MixRampCommand::Process(const ADSP::CommandListProcessor& processor) {
+    auto output{processor.mix_buffers.subspan(output_index * processor.sample_count,
+                                              processor.sample_count)};
+    auto input{processor.mix_buffers.subspan(input_index * processor.sample_count,
+                                             processor.sample_count)};
+    const auto ramp{(volume - prev_volume) / static_cast<f32>(processor.sample_count)};
+    auto prev_sample_ptr{reinterpret_cast<s32*>(previous_sample)};
+
+    // If previous volume and ramp are both 0, nothing will be added to the output, so just skip.
+    if (prev_volume == 0.0f && ramp == 0.0f) {
+        *prev_sample_ptr = 0;
+        return;
+    }
+
+    switch (precision) {
+    case 15:
+        *prev_sample_ptr =
+            ApplyMixRamp<15>(output, input, prev_volume, ramp, processor.sample_count);
+        break;
+
+    case 23:
+        *prev_sample_ptr =
+            ApplyMixRamp<23>(output, input, prev_volume, ramp, processor.sample_count);
+        break;
+
+    default:
+        LOG_ERROR(Service_Audio, "Invalid precision {}", precision);
+        break;
+    }
+}
+
+bool MixRampCommand::Verify(const ADSP::CommandListProcessor& processor) {
+    return true;
+}
+
+} // namespace AudioCore::AudioRenderer