engine: presets E/F AutoExposure, the game's exposure fields and NGX's jitter order

NGX's CNN takes this frame's exposure scale and pre-exposure in both translated kernels (input words 244-256,
reconstruction 592-604) and the previous frame's exposure as the input kernel's texture 352
(cuda_copy_exposure_kernel's half surface). The runtime left all of it at the model dump's values, so HDR games
with a pre-exposure other than 1 or a changing exposure measured 18-39 dB against NGX; now 54-64 dB.

AutoExposure (flag 0x40), which the shim refused for E/F: NGX runs K's log-mean measurement on M's grid every
second frame. exposure_k.comp MODE 3 writes it to the 1x1 image the kernels sample; sr/exposure_copy_e.comp
keeps the previous exposure. 60-66 dB over eleven frames at 960x540 -> 1920x1080, pre-exposure 19-21.

The reconstruction's jitter words 544-556 are (y, x); the runtime wrote (-x, -y), which matches only the
harness's first three jitters, so every later frame of a game's jitter sequence measured 26-28 dB. Twelve-frame
captures now measure 60-66 dB HDR and LDR; on the Steam Deck through the shim 51-67 dB against ZLUDA.

The D3D12 harness takes per-frame lists in D4R_HARNESS_PRE_EXPOSURE / _EXPOSURE_SCALE; d4r-e takes the
AutoExposure flag, per-frame exposure values and the game's exposure texture. E/F models need rebuilding
(the install's model cache key changes); older models keep the old binding and refuse AutoExposure.

engine/README.md

@@ -1147,7 +1147,25 @@ in two constants.
   packed in the DLL; NGX uploads them unpacked), `runtime_e.inc` is `EModel` / `EEngine`, `game_e.cpp` the game
   adapter, `replay_e.cpp` the replay (`d4r-e`). The shim runs presets 5 and 6 with `engine\e` / `engine\f`
   (`D4R_ENGINE_MODEL_E_DIR`, `_F_DIR`), LDR or HDR, either motion resolution, any render size (a new size rebuilds
-  the engine); not with AutoExposure. `build-engine-models.sh` builds both.
+  the engine), the game's exposure texture or AutoExposure. `build-engine-models.sh` builds both.
+- Exposure (HDR; harness captures with per-frame pre-exposure, exposure scale and exposure texture schedules,
+  2026-10-19). Both translated kernels take this frame's exposure scale (twice), pre-exposure and 1 / pre-exposure
+  (input words 244-256, reconstruction 592-604). They sample the exposure as 1x1 textures: the input kernel's 344 and
+  360 and the reconstruction's 472 and 480 this frame's, the input kernel's 352 the previous frame's, which NGX's
+  `cuda_copy_exposure_kernel` copies into a half surface after each frame (the current one on a reset frame):
+  `sr/exposure_copy_e.comp`. With AutoExposure NGX runs K's measurement (`cuda_luma_convert_kernel`, three
+  `cuda_reduce_sum_kernel`, `cuda_auto_exposure_copy_kernel`: key 0.18 / 0.82 times exp(-mean log luma), the luma
+  scaled by 1 / pre-exposure, truncated to half) on every second frame from the first, on M's grid (half the output,
+  half the render size but at least 256 above 2x), and ignores the game's texture: `exposure_k.comp` MODE 3. The
+  engine used to leave all of this at the model dump's values (exposure 1, the current exposure as the previous one):
+  at 1280x720 -> 1920x1080 with pre-exposure 4/2/8 and scale 0.5/0.75/1.25 it measured 39/18/29 dB against NGX with
+  the game's texture, now 64/55/54 dB; with AutoExposure 65/54/54 dB, through the shim as through `d4r-e` (neutral
+  exposure: 64-66 dB, unchanged). Models built before this keep the old binding and refuse AutoExposure.
+- The reconstruction's jitter words 544-556 are the previous and this frame's jitter as (y, x). The runtime wrote
+  (-x, -y), which agrees only on the harness's first three jitters (0, -+0.25), so three-frame checks passed while
+  later frames of the jitter sequence measured 26-28 dB (every game's Halton jitter was affected). Twelve-frame
+  captures at 640x360 -> 1280x720 now measure 60-66 dB (HDR), 61-66 dB (LDR), and with AutoExposure at
+  960x540 -> 1920x1080 and pre-exposure 19-21 60-66 dB; on the Steam Deck through the shim 51-67 dB against ZLUDA.
 
 With the f32 reconstruction head, accuracy against NGX through ZLUDA (three temporal frames): 63-68 dB at 640x360 -> 1280x720
 (LDR and HDR, both motion resolutions, E and F), 1280x720 -> 1920x1080, 1001x563 -> 1501x845 (generic kernel),

engine/compile_sr_e.py

@@ -20,6 +20,8 @@ variants use aligned word accesses for their packed tensors. Writes:
   <stage>.spv               the network stages
   input-<v>.spv / .globals.bin, final-<v>.spv / .globals.bin   the translated kernels
   input.args, final.args    their argument blocks from the dump (the runtime rewrites every frame-dependent field)
+  exposure_e0.spv / _e1.spv NGX's AutoExposure measurement (engine/exposure_k.comp MODE 3)
+  exposure_copy_e.spv       NGX's copy of the frame's exposure that the next frame reads (engine/sr/exposure_copy_e.comp)
 Everything but d4r's shaders is derived from the user's DLL: it stays on their machine and is never packaged.
 """
 import argparse
@@ -198,7 +200,11 @@ def main():
         for off in l.ptr:
             block[off:off + 8] = bytes(8)
         (out / f'{name}.args').write_bytes(bytes(block))
-    lines += ['template input input.args', 'template final final.args']
+    for p in '01':
+        glsl(HERE / 'exposure_k.comp', out / f'exposure_e{p}.spv', ['-DMODE=3', f'-DPASS={p}'])
+    glsl(HERE / 'sr' / 'exposure_copy_e.comp', out / 'exposure_copy_e.spv')
+    lines += ['template input input.args', 'template final final.args', 'exposure exposure_e0.spv exposure_e1.spv',
+              'exposure_copy exposure_copy_e.spv']
     (out / 'e.txt').write_text('\n'.join(lines) + '\n')
     print(f'Super Resolution CNN model in {out} ({len(blob)} weight bytes)')
 

engine/exposure_k.comp

@@ -5,6 +5,8 @@
 //          [0, 10000], 0.005).
 //   MODE 2 (Ray Reconstruction, the same cuda_dldn_engine_* kernels): MODE 1's measurement, written to two 1x1
 //          images instead of stage parameter blocks.
+//   MODE 3 (presets E and F, NGX's cuda_luma_convert / auto_exposure_copy kernels): MODE 0's measurement, written to
+//          the 1x1 image the input and reconstruction kernels sample as the exposure.
 // Both modes measure the same grid: the colour rectangle sampled at half the output size with an
 // endpoint-aligned nearest-texel lookup (the reference's cuda_luma_convert_kernel; the grid equals the
 // rectangle itself only when the render size is half the output size).
@@ -17,6 +19,7 @@
 #ifndef MODE
 #define MODE 0
 #endif
+#define LOG_MEAN (MODE == 0 || MODE == 3)   // key * exp(-mean of the log luma)
 layout(local_size_x = 64) in;
 layout(set = 0, binding = 0, std430) readonly buffer Params
 {
@@ -63,7 +66,7 @@ void main()
             const vec3 c = texelFetch(colorTex, p.origin + sampleAt, 0).rgb;
             // the reference accumulates the logarithm of the exposed luma (cuda_luma_convert_kernel). The
             // constant is applied to Y = fma(b, 0.25, fma(r, 0.25, g * 0.5)); MODE 1 keeps its own expression.
-#if MODE == 0
+#if LOG_MEAN
             precise const float luma = p.scale * fma(c.b, 0.25, fma(c.r, 0.25, 0.5 * c.g));
             // log(luma + 1e-6) as lg2(x) * ln2, and a non-finite or non-positive luma contributes nothing
             if (luma > 0.0 && !isinf(luma))
@@ -93,6 +96,8 @@ layout(set = 0, binding = 5) uniform sampler2D gameExposure;
 layout(set = 0, binding = 3, std430) buffer InputParams { float w[]; } inp;     // enc0_m: expo, expoPrev at words 25, 26
 layout(set = 0, binding = 4, std430) buffer PostParams { float w[]; } post;     // post_m: words 14, 15
 layout(set = 0, binding = 5, std430) buffer DownParams { float w[]; } down;     // down_m: word 12
+#elif MODE == 3
+layout(set = 0, binding = 3, r16f) uniform writeonly image2D exposureOut;
 #else
 // MODE 2 (Ray Reconstruction): the denoiser's stages sample the exposure as two 1x1 textures, this frame's and
 // the previous frame's (zero on the first frame and after a reset)
@@ -124,7 +129,7 @@ void main()
     {
         float mean = 0.0;
         for (uint i = 0u; i < 64u; ++i) mean += part[i];
-#if MODE == 0
+#if LOG_MEAN
         // auto_exposure_copy_kernel: key * exp2(-log2e * sum), written to a half surface. The formatted
         // store truncates toward zero, as in MODE 1 (measured on the captured K exposure: the store lands
         // one binary16 code below the correctly rounded value).
@@ -136,7 +141,7 @@ void main()
         float measured = truncatedHalf(full);
 #endif
         if (!(measured > 0.0) || isinf(measured)) measured = 1.0;
-#if MODE == 0
+#if LOG_MEAN
         previous = (p.flags & 2u) != 0u ? measured : current;
 #else
         previous = (p.flags & 2u) != 0u ? 0.0 : current;       // 0: no earlier exposure (the stages read it as 1)
@@ -154,6 +159,8 @@ void main()
     inp.w[25] = current; inp.w[26] = previous;
     post.w[14] = current; post.w[15] = previous;
     down.w[12] = current;
+#elif MODE == 3
+    imageStore(exposureOut, ivec2(0), vec4(current));
 #else
     imageStore(exposureOut, ivec2(0), vec4(current));
     imageStore(previousOut, ivec2(0), vec4(previous));

engine/game_e.cpp

@@ -9,13 +9,15 @@ struct GameUpscalerE::Impl {
     uint32_t width, height, outputWidth, outputHeight, motionWidth, motionHeight;
     game_detail::CanonicalInputs fallback;
     bool started = false;
-    Impl(EModel& m, VkPhysicalDevice p, VkDevice d, uint32_t ow, uint32_t oh, uint32_t rw, uint32_t rh, bool hdr, bool lowRes)
-        : model(m), engine(m, rw, rh, ow, oh, hdr, lowRes), width(rw), height(rh), outputWidth(ow), outputHeight(oh),
+    Impl(EModel& m, VkPhysicalDevice p, VkDevice d, uint32_t ow, uint32_t oh, uint32_t rw, uint32_t rh, bool hdr, bool lowRes,
+         bool autoExposure)
+        : model(m), engine(m, rw, rh, ow, oh, hdr, lowRes, autoExposure), width(rw), height(rh), outputWidth(ow), outputHeight(oh),
           motionWidth(lowRes ? rw : ow), motionHeight(lowRes ? rh : oh), fallback(p, d, rw, rh, motionWidth, motionHeight) {}
 };
 GameUpscalerE::GameUpscalerE(EModel& model, VkPhysicalDevice physical, VkDevice device, uint32_t outputWidth, uint32_t outputHeight,
-                             uint32_t renderWidth, uint32_t renderHeight, bool hdr, bool lowResMotion)
-    : impl(std::make_unique<Impl>(model, physical, device, outputWidth, outputHeight, renderWidth, renderHeight, hdr, lowResMotion)) {}
+                             uint32_t renderWidth, uint32_t renderHeight, bool hdr, bool lowResMotion, bool autoExposure)
+    : impl(std::make_unique<Impl>(model, physical, device, outputWidth, outputHeight, renderWidth, renderHeight, hdr, lowResMotion,
+                                  autoExposure)) {}
 GameUpscalerE::~GameUpscalerE() = default;
 
 void GameUpscalerE::record(VkCommandBuffer cb, const GameFrameE& frame) {
@@ -39,6 +41,7 @@ void GameUpscalerE::record(VkCommandBuffer cb, const GameFrameE& frame) {
     s.jitter[0] = frame.jitter[0]; s.jitter[1] = frame.jitter[1];
     s.motionScale[0] = frame.motionScale[0]; s.motionScale[1] = frame.motionScale[1];
     s.reset = frame.reset;
+    s.preExposure = frame.preExposure; s.exposureScale = frame.exposureScale;
     FrameImages images{};
     images.color = directColor ? frame.color.view : g.fallback.color.view;
     images.motion = directMotion ? frame.motion.view : g.fallback.motion.view;

engine/game_e.h

@@ -6,17 +6,19 @@
 namespace d4r {
 struct GameFrameE {
     GameImage color, depth, motion, output;     // as for GameUpscaler; compatible views at origin zero may be borrowed
-    GameImage exposure;                         // HDR: the game's 1x1 float exposure (a sampled view), else 1
+    GameImage exposure;                         // HDR without autoExposure: the game's 1x1 float exposure (a sampled view), else 1
     float jitter[2] = {0, 0};
     float motionScale[2] = {1, 1};              // NGX's MV scale
+    float preExposure = 1, exposureScale = 1;   // the game's (DLSS.Pre.Exposure, DLSS.Exposure.Scale)
     bool reset = false;
 };
 class GameUpscalerE {
 public:
     // The model must outlive this object. Render size fixed for its lifetime (a new size needs a new adapter).
-    // lowResMotion: motion at the render size (NGX's MVLowRes), otherwise at the output size.
+    // lowResMotion: motion at the render size (NGX's MVLowRes), otherwise at the output size. autoExposure: NGX's
+    // AutoExposure (HDR), the exposure measured from the colour (EModel::hasAutoExposure).
     GameUpscalerE(EModel& model, VkPhysicalDevice physical, VkDevice device, uint32_t outputWidth, uint32_t outputHeight,
-                  uint32_t renderWidth, uint32_t renderHeight, bool hdr, bool lowResMotion);
+                  uint32_t renderWidth, uint32_t renderHeight, bool hdr, bool lowResMotion, bool autoExposure = false);
     ~GameUpscalerE(); // only once every recorded frame has completed on the GPU
     GameUpscalerE(const GameUpscalerE&) = delete;
     GameUpscalerE& operator=(const GameUpscalerE&) = delete;

engine/replay_e.cpp

@@ -2,9 +2,10 @@
 // after frame, and writes the output (and with D4R_E_DUMP_TENSORS=1 the network's tensors) after each frame.
 //
 // usage: d4r-e MODEL_DIR INPUT_DIR OUT_DIR
-//   INPUT_DIR: frames.txt ("size RW RH OW OH HDR LOWRES MW MH", then per frame "frame F jx jy mvsx mvsy reset") and
+//   INPUT_DIR: frames.txt ("size RW RH OW OH HDR LOWRES MW MH [AUTOEXPOSURE]", then per frame
+//   "frame F jx jy mvsx mvsy reset [preExposure exposureScale]") and
 //   F-color.bin (RGBA16F, render size), F-motion.bin (RG16F, MW x MH),
-//   F-depth.bin (R32F, render size, with LOWRES). D4R_E_TIME_REPEAT=N: best of N GPU timings per frame.
+//   F-depth.bin (R32F, render size, with LOWRES), optionally F-exposure.bin (R32F 1x1: the game's exposure, HDR). D4R_E_TIME_REPEAT=N: best of N GPU timings per frame.
 #include "runtime.h"
 #include <algorithm>
 #include <cstdlib>
@@ -125,11 +126,16 @@ int main(int argc, char** argv) try {
     auto framesText = read(inputDir + "/frames.txt");
     std::istringstream frames(std::string(framesText.begin(), framesText.end()));
     std::string key;
-    uint32_t rw, rh, ow, oh, hdr, lowRes, mw, mh;
-    frames >> key >> rw >> rh >> ow >> oh >> hdr >> lowRes >> mw >> mh;
+    uint32_t rw, rh, ow, oh, hdr, lowRes, mw, mh, autoExposure = 0;
+    std::string sizeLine;
+    std::getline(frames, sizeLine);
+    std::istringstream size(sizeLine);
+    size >> key >> rw >> rh >> ow >> oh >> hdr >> lowRes >> mw >> mh;
+    size >> autoExposure;
     d4r::EModel model(c.physical, c.device, modelDir);
-    d4r::EEngine engine(model, rw, rh, ow, oh, hdr != 0, lowRes != 0);
+    d4r::EEngine engine(model, rw, rh, ow, oh, hdr != 0, lowRes != 0, autoExposure != 0);
     Input color(c, VK_FORMAT_R16G16B16A16_SFLOAT, rw, rh), motion(c, VK_FORMAT_R16G16_SFLOAT, mw, mh), depth(c, VK_FORMAT_R32_SFLOAT, rw, rh);
+    Input exposure(c, VK_FORMAT_R32_SFLOAT, 1, 1);
     HostBuffer staging(c, std::max<VkDeviceSize>(VkDeviceSize(ow) * oh * 8, 64u << 20));
     VkQueryPoolCreateInfo qp{VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO};
     qp.queryType = VK_QUERY_TYPE_TIMESTAMP; qp.queryCount = 4;
@@ -148,16 +154,22 @@ int main(int argc, char** argv) try {
             barrier(cb, in.image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_GENERAL);
         });
     };
-    while (frames >> key) {
+    for (std::string line; std::getline(frames, line);) {
+        std::istringstream fields(line);
+        if (!(fields >> key)) continue;
         uint32_t f; int reset;
         d4r::EFrameSettings s;
-        frames >> f >> s.jitter[0] >> s.jitter[1] >> s.motionScale[0] >> s.motionScale[1] >> reset;
+        fields >> f >> s.jitter[0] >> s.jitter[1] >> s.motionScale[0] >> s.motionScale[1] >> reset;
+        if (!(fields >> s.preExposure >> s.exposureScale)) s.preExposure = s.exposureScale = 1;
         s.reset = reset != 0;
         upload(color, "color", f, rw, rh, 8);
         upload(motion, "motion", f, mw, mh, 4);
         if (lowRes) upload(depth, "depth", f, rw, rh, 4);
+        const bool gameExposure = std::ifstream(inputDir + "/" + std::to_string(f) + "-exposure.bin").good();
+        if (gameExposure) upload(exposure, "exposure", f, 1, 1, 4);
         d4r::FrameImages images{};
         images.color = color.view; images.motion = motion.view; images.depth = depth.view;
+        if (gameExposure) images.exposure = exposure.view;
         engine.setFrame(images, s);
         if (first) c.submit([&](VkCommandBuffer cb) { model.recordUpload(cb); engine.recordInitialize(cb); first = false; });
         double best = 1e30, in = 0, net = 0, fin = 0;

engine/runtime.h

@@ -317,6 +317,7 @@ struct EFrameSettings {
     float jitter[2] = {0, 0};       // render pixels, as the game passes them to NGX
     float motionScale[2] = {1, 1};  // NGX's MV scale: motion texels times this are the motion's pixels
     bool reset = false;
+    float preExposure = 1, exposureScale = 1;   // the game's (DLSS.Pre.Exposure, DLSS.Exposure.Scale)
 };
 class EModel {
 public:
@@ -326,6 +327,7 @@ public:
     EModel& operator=(const EModel&) = delete;
     void recordUpload(VkCommandBuffer command);
     bool uploadRecorded() const;
+    bool hasAutoExposure() const;   // the model directory holds the exposure shaders (exposure_e0/1.spv)
 private:
     struct Impl;
     std::unique_ptr<Impl> impl;
@@ -335,14 +337,16 @@ class EEngine {
 public:
     // hdr: NGX's IsHDR (linear colour, the exposure textures); lowResMotion: MVLowRes (render-size motion vectors,
     // in render pixels; otherwise output-size motion in output pixels). Render size at most the output size.
+    // autoExposure (HDR): NGX's AutoExposure, the exposure measured from the colour on every second frame instead of
+    // read from images.exposure (needs EModel::hasAutoExposure).
     EEngine(EModel& model, uint32_t renderWidth, uint32_t renderHeight, uint32_t outputWidth, uint32_t outputHeight,
-            bool hdr, bool lowResMotion);
+            bool hdr, bool lowResMotion, bool autoExposure = false);
     ~EEngine();
     EEngine(const EEngine&) = delete;
     EEngine& operator=(const EEngine&) = delete;
     void recordInitialize(VkCommandBuffer command);
     // color (and depth with lowResMotion) at the render size, motion at the render or output size; images.exposure
-    // the game's 1x1 exposure (HDR; 1 when absent). A borrowed RGBA16F finalOutput (GENERAL) is written directly.
+    // the game's 1x1 exposure (HDR without autoExposure; 1 when absent). A borrowed RGBA16F finalOutput (GENERAL) is written directly.
     void setFrame(const FrameImages& images, const EFrameSettings& settings, FrameOutput finalOutput = {});
     // With a timestamp query pool, four stamps are written from query `first`: start, after the input kernel, after
     // the network and after the reconstruction.

engine/runtime_e.inc

@@ -50,6 +50,10 @@ struct EModel::Impl {
     std::map<std::string, std::unique_ptr<ETranslated>> input, final;
     std::vector<uint8_t> inputTemplate, finalTemplate;
     bool uploaded = false;
+    std::array<Pipeline, 2> exposure;   // engine/exposure_k.comp MODE 3 (NGX's AutoExposure), when the model has it
+    bool hasExposure = false;
+    Pipeline exposureCopy;              // engine/sr/exposure_copy_e.comp: the previous frame's exposure (HDR)
+    bool hasExposureCopy = false;
     uint32_t preset = 5;            // 5: E, 6: F
     float kspread = 0.035f;         // the reconstruction's constant at 584 times rx ry (E 0.035, F 0.1)
     Impl(VkPhysicalDevice physical, VkDevice dev, const std::string& dir, VkPipelineCache c)
@@ -101,6 +105,18 @@ struct EModel::Impl {
                     k.surfaces.emplace_back(static_cast<uint32_t>(std::stoul(item.substr(0, colon))), item.substr(colon + 1));
                 }
                 (key == "input" ? input : final)[variant] = std::move(entry);
+            } else if (key == "exposure") {
+                // "exposure PASS0.spv PASS1.spv": the measurement over the colour, then the 1x1 exposure image
+                std::string measure, update; f >> measure >> update;
+                const auto t = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, s = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
+                exposure[0].create(device.handle, dir + "/" + measure, {b, t, b}, 32, cache);
+                exposure[1].create(device.handle, dir + "/" + update, {b, b, b, s}, 32, cache);
+                hasExposure = true;
+            } else if (key == "exposure_copy") {
+                std::string shader; f >> shader;
+                exposureCopy.create(device.handle, dir + "/" + shader, {VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+                                                                        VK_DESCRIPTOR_TYPE_STORAGE_IMAGE}, 32, cache);
+                hasExposureCopy = true;
             } else if (key == "template") {
                 std::string which, file; f >> which >> file;
                 auto bytes = read(dir + "/" + file);
@@ -143,12 +159,13 @@ void EModel::recordUpload(VkCommandBuffer cb) {
     m.uploaded = true;
 }
 bool EModel::uploadRecorded() const { return impl->uploaded; }
+bool EModel::hasAutoExposure() const { return impl->hasExposure; }
 
 struct EEngine::Impl {
     EModel::Impl& model;
     const Device& d;
     uint32_t rw, rh, ow, oh, pw, ph, h0, w0;   // render, output, the output padded to 128, the token grid
-    bool hdr, lowRes;
+    bool hdr, lowRes, autoExposure;
     ETranslated *input = nullptr, *final = nullptr;
     std::string finalVariant;
     uint32_t finalGrid[2] = {0, 0};
@@ -161,6 +178,13 @@ struct EEngine::Impl {
     std::vector<uint8_t> paramStaging, inBlock, finBlock;
     std::array<Tex, 2> history, motionHistory;
     Tex warped, discard, zero, exposureOne, out;
+    // AutoExposure: NGX's measurement (exposure_k.comp MODE 3) into `measured`, the 1x1 the kernels then sample
+    Buffer expP, expSums, expState;
+    ExposureParams exposure{};
+    Tex measured;
+    VkDescriptorSet exp1Set = VK_NULL_HANDLE;
+    // HDR with a model that has the copy shader: the previous frame's exposure, the input kernel's texture 352
+    Tex previousExposure;
     bool outNew = false;
     VkSampler nearest = VK_NULL_HANDLE, linear = VK_NULL_HANDLE;
     VkDescriptorPool fixedPool = VK_NULL_HANDLE;
@@ -170,6 +194,8 @@ struct EEngine::Impl {
         FrameOutput finalOutput{};
         VkDescriptorPool pool = VK_NULL_HANDLE;
         std::array<VkDescriptorSet, 2> input{}, final{};
+        VkDescriptorSet exposure = VK_NULL_HANDLE;   // the measurement over this colour view (AutoExposure)
+        VkDescriptorSet copy = VK_NULL_HANDLE;       // this frame's exposure into previousExposure
     };
     std::vector<Bindings> bindings;
     const Bindings* bound = nullptr;
@@ -182,10 +208,15 @@ struct EEngine::Impl {
     uint32_t lh(uint32_t l) const { return h0 >> l; }
     uint32_t lw(uint32_t l) const { return w0 >> l; }
 
-    Impl(EModel::Impl& m, uint32_t renderWidth, uint32_t renderHeight, uint32_t outputWidth, uint32_t outputHeight, bool isHdr, bool lowResMotion)
-        : model(m), d(m.device), rw(renderWidth), rh(renderHeight), ow(outputWidth), oh(outputHeight), hdr(isHdr), lowRes(lowResMotion) {
+    Impl(EModel::Impl& m, uint32_t renderWidth, uint32_t renderHeight, uint32_t outputWidth, uint32_t outputHeight, bool isHdr,
+         bool lowResMotion, bool isAutoExposure)
+        : model(m), d(m.device), rw(renderWidth), rh(renderHeight), ow(outputWidth), oh(outputHeight), hdr(isHdr), lowRes(lowResMotion),
+          autoExposure(isAutoExposure) {
         if (rw < 32 || rh < 32 || rw > ow || rh > oh || ow > 16384 || oh > 16384)
             throw std::runtime_error("unsupported preset E/F dimensions");
+        if (autoExposure && (!hdr || !model.hasExposure))
+            throw std::runtime_error(hdr ? "the preset E/F model has no exposure shaders (rebuild it with compile_sr_e.py)"
+                                         : "automatic exposure needs HDR colour");
         pw = (ow + 127) & ~127u; ph = (oh + 127) & ~127u; w0 = pw / 4; h0 = ph / 4;
         // The mid kernel uses the actual scale/jitter and also covers the integer-rounded 2/3 render sizes.
         // Requiring exact 3:2 dimensions sends e.g. 853x533 -> 1280x800 through the much larger generic kernel.
@@ -234,15 +265,38 @@ struct EEngine::Impl {
         discard.create(d, 1, 1, half4);
         zero.create(d, 1, 1, half4);
         exposureOne.create(d, 1, 1, VK_FORMAT_R32_SFLOAT);
+        if (autoExposure) {
+            // NGX's cuda_luma_convert_kernel grid (harness captures 2026-10-19, like M's and L's): half the output,
+            // half the render size but at least 256 where the output is more than twice the render size
+            const uint32_t gx = exposureGrid(rw, ow), gy = exposureGrid(rh, oh);
+            exposure.size[0] = int32_t(rw); exposure.size[1] = int32_t(rh);
+            exposure.sampleSize[0] = int32_t(gx); exposure.sampleSize[1] = int32_t(gy);
+            exposure.invCount = 1.0f / float(gx * gy);
+            exposure.key = 0.18f / 0.82f;   // cuda_auto_exposure_copy_kernel's argument 0
+            exposure.blocksX = (gx + 31) / 32;
+            exposure.blocks = exposure.blocksX * ((gy + 31) / 32);
+            expP.create(d, sizeof(ExposureParams), storage);
+            expSums.create(d, VkDeviceSize(exposure.blocks) * 4, storage);
+            expState.create(d, 8, storage);
+            measured.create(d, 1, 1, VK_FORMAT_R16_SFLOAT);
+        }
+        if (hdr && model.hasExposureCopy) previousExposure.create(d, 1, 1, VK_FORMAT_R16_SFLOAT);
         VkSamplerCreateInfo si{VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO};
         si.addressModeU = si.addressModeV = si.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE; si.maxLod = 0;
         VKCHECK(vkCreateSampler(d.handle, &si, nullptr, &nearest));
         si.magFilter = si.minFilter = VK_FILTER_LINEAR;
         VKCHECK(vkCreateSampler(d.handle, &si, nullptr, &linear));
-        VkDescriptorPoolSize sizes[] = {{VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 3 * ENet}};
+        VkDescriptorPoolSize sizes[] = {{VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 3 * ENet + 3}, {VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1}};
         VkDescriptorPoolCreateInfo pi{VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO};
-        pi.maxSets = ENet; pi.poolSizeCount = 1; pi.pPoolSizes = sizes;
+        pi.maxSets = ENet + 1; pi.poolSizeCount = 2; pi.pPoolSizes = sizes;
         VKCHECK(vkCreateDescriptorPool(d.handle, &pi, nullptr, &fixedPool));
+        if (autoExposure) {
+            exp1Set = descriptorSet(d.handle, fixedPool, model.exposure[1].descriptors);
+            bindBuffer(d.handle, exp1Set, 0, expP);
+            bindBuffer(d.handle, exp1Set, 1, expSums);
+            bindBuffer(d.handle, exp1Set, 2, expState);
+            bindImage(d.handle, exp1Set, 3, measured.view);
+        }
         for (unsigned s = 0; s < ENet; ++s) {
             netSets[s] = descriptorSet(d.handle, fixedPool, model.stages[s].descriptors);
             bindRange(d.handle, netSets[s], 0, params, paramAt[s]);
@@ -261,8 +315,8 @@ struct EEngine::Impl {
     // what a translated kernel's texture or surface argument is (NGX's wiring in the captures; null where NGX leaves
     // it unbound). par: this frame's parity (history written this frame, the other one read)
     Resource resolve(bool isInput, bool surface, uint32_t offset, uint32_t par, const FrameImages& in, VkImageView output) const {
-        const VkImageView exposure = hdr ? (in.exposure ? in.exposure : exposureOne.view) : VK_NULL_HANDLE;
-        const VkImageLayout exposureLayout = in.exposure ? in.exposureLayout : VK_IMAGE_LAYOUT_GENERAL;
+        const VkImageView exposure = !hdr ? VK_NULL_HANDLE : autoExposure ? measured.view : in.exposure ? in.exposure : exposureOne.view;
+        const VkImageLayout exposureLayout = !autoExposure && in.exposure ? in.exposureLayout : VK_IMAGE_LAYOUT_GENERAL;
         if (isInput) {
             if (!surface) switch (offset) {
                 case 280: return {in.color, true, in.colorLayout};
@@ -270,7 +324,10 @@ struct EEngine::Impl {
                 case 304: return {in.motion, false, in.motionLayout};
                 case 312: return {in.depth, false, in.depthLayout};
                 case 320: return {motionHistory[par ^ 1].view, true};
-                case 344: case 352: case 360: return {exposure, false, exposureLayout};
+                case 344: case 360: return {exposure, false, exposureLayout};
+                // NGX: the previous frame's exposure (its copy kernel's surface; the current one on a reset frame,
+                // where the engine copies first). Models without the copy shader bind the current exposure.
+                case 352: return previousExposure.view ? Resource{previousExposure.view} : Resource{exposure, false, exposureLayout};
             } else switch (offset) {
                 case 328: return {motionHistory[par].view};
                 case 368: return {discard.view};
@@ -310,6 +367,9 @@ struct EEngine::Impl {
             throw std::runtime_error("preset E/F needs colour and motion (and depth with render-size motion)");
         if (finalOutput.view && finalOutput.format != VK_FORMAT_R16G16B16A16_SFLOAT)
             throw std::runtime_error("preset E/F writes RGBA16F output only");
+        if (!(settings.preExposure > 0.0f) || !std::isfinite(settings.preExposure) || !(settings.exposureScale > 0.0f) ||
+            !std::isfinite(settings.exposureScale))
+            throw std::runtime_error("the pre-exposure and exposure scale must be positive numbers");
         const bool rst = settings.reset || frame == 0;
         const float frw = float(rw), frh = float(rh), fow = float(ow), foh = float(oh);
         const float rx = frw / fow, ry = frh / foh;
@@ -328,6 +388,10 @@ struct EEngine::Impl {
         put32(p, 136, rw); put32(p, 140, rh); putF(p, 144, rx); putF(p, 148, ry);
         putF(p, 152, 1.0f / fow); putF(p, 156, 1.0f / foh); putF(p, 160, model.preset == 5 ? 500.0f / foh : 1.0f);
         put32(p, 184, lowRes ? 1u : 0u); put32(p, 188, lowRes ? 1u : 0u);
+        // the game's exposure scale (twice), pre-exposure and its inverse: both kernels take this frame's values, with
+        // or without AutoExposure (captures with per-frame schedules, 2026-10-19); the kept measurement is not rescaled
+        const float exposureFields[4] = {settings.exposureScale, settings.exposureScale, settings.preExposure, 1.0f / settings.preExposure};
+        for (unsigned i = 0; i < 4; ++i) putF(p, 244 + 4 * i, exposureFields[i]);
         put64(p, 376, at[0]);
         auto& o = finBlock;
         o = model.finalTemplate;
@@ -337,9 +401,12 @@ struct EEngine::Impl {
         put32(o, 312, w0 * 32); put32(o, 316, w0 * 32); put32(o, 320, w0 * 40);
         put32(o, 504, oh); put32(o, 508, ow); put32(o, 512, hdr ? 1u : 0u);
         putF(o, 528, ry); putF(o, 532, 1.0f / ry); putF(o, 536, rx); putF(o, 540, 1.0f / rx);
-        putF(o, 544, -pj[0]); putF(o, 548, -pj[1]); putF(o, 552, -settings.jitter[0]); putF(o, 556, -settings.jitter[1]);
+        // the previous and this frame's jitter as (y, x): (-x, -y) agrees with it only on the harness's first three
+        // jitters (0 / -+0.25), so later frames of a Halton sequence measured 26-28 dB (six-frame captures, 2026-10-19)
+        putF(o, 544, pj[1]); putF(o, 548, pj[0]); putF(o, 552, settings.jitter[1]); putF(o, 556, settings.jitter[0]);
         put32(o, 564, rh - 1); put32(o, 572, rw - 1);
         putF(o, 584, model.kspread / (rx * ry));
+        for (unsigned i = 0; i < 4; ++i) putF(o, 592 + 4 * i, exposureFields[i]);
         put64(o, 0, at[16]); put64(o, 8, at[1]);
         for (unsigned i = 0; i < 4; ++i) put64(o, model.head[i].arg, headAt[i]);
         put64(o, 256, scratch);
@@ -361,15 +428,27 @@ struct EEngine::Impl {
             b.images = images; b.finalOutput = finalOutput;
             const uint32_t tex = 2 * uint32_t(input->textures.size() + final->textures.size());
             const uint32_t surf = 2 * uint32_t(input->surfaces.size() + final->surfaces.size());
-            VkDescriptorPoolSize sizes[] = {{VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 12}, {VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, tex},
-                                            {VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, surf}};
+            VkDescriptorPoolSize sizes[] = {{VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 14}, {VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, tex + 2},
+                                            {VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, surf + 1}};
             VkDescriptorPoolCreateInfo pi{VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO};
-            pi.maxSets = 4; pi.poolSizeCount = 3; pi.pPoolSizes = sizes;
+            pi.maxSets = 6; pi.poolSizeCount = 3; pi.pPoolSizes = sizes;
             VKCHECK(vkCreateDescriptorPool(d.handle, &pi, nullptr, &b.pool));
             for (uint32_t par = 0; par < 2; ++par) {
                 b.input[par] = translatedSet(b, true, par, output);
                 b.final[par] = translatedSet(b, false, par, output);
             }
+            if (autoExposure) {
+                b.exposure = descriptorSet(d.handle, b.pool, model.exposure[0].descriptors);
+                bindBuffer(d.handle, b.exposure, 0, expP);
+                bindImage(d.handle, b.exposure, 1, images.color, nearest, images.colorLayout);
+                bindBuffer(d.handle, b.exposure, 2, expSums);
+            }
+            if (previousExposure.view) {
+                const auto current = resolve(true, false, 344, 0, images, output);
+                b.copy = descriptorSet(d.handle, b.pool, model.exposureCopy.descriptors);
+                bindImage(d.handle, b.copy, 0, current.view, nearest, current.layout);
+                bindImage(d.handle, b.copy, 1, previousExposure.view);
+            }
             bindings.push_back(std::move(b));
             found = bindings.end() - 1;
         }
@@ -380,6 +459,12 @@ struct EEngine::Impl {
             std::ofstream(std::string(dump) + "/" + std::to_string(frame + 1) + "-final.args", std::ios::binary)
                 .write(reinterpret_cast<const char*>(finBlock.data()), static_cast<std::streamsize>(finBlock.size()));
         }
+        if (autoExposure) {
+            // NGX measures on every second evaluation from the first (and K's rule: on a reset too); the luma is
+            // scaled by 1 / pre-exposure, and the image keeps the last measurement on the frames between
+            exposure.scale = 1.0f / settings.preExposure;
+            exposure.flags = (frame % 2 == 0 || rst ? 1u : 0u) | (rst ? 2u : 0u);
+        }
         reset = rst;
         prevJitter[0] = settings.jitter[0]; prevJitter[1] = settings.jitter[1];
     }
@@ -387,6 +472,8 @@ struct EEngine::Impl {
         VkClearColorValue clear{};
         VkImageSubresourceRange range{VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1};
         std::vector<VkImage> images{warped.handle, discard.handle, zero.handle, exposureOne.handle};
+        if (autoExposure) images.push_back(measured.handle);
+        if (previousExposure.handle) images.push_back(previousExposure.handle);
         for (int i = 0; i < 2; ++i) { images.push_back(history[i].handle); images.push_back(motionHistory[i].handle); }
         for (VkImage image : images) {
             imageBarrier(cb, image, VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_GENERAL, VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
@@ -396,6 +483,7 @@ struct EEngine::Impl {
         VkClearColorValue one{}; one.float32[0] = 1.0f;
         vkCmdClearColorImage(cb, exposureOne.handle, VK_IMAGE_LAYOUT_GENERAL, &one, 1, &range);
         vkCmdFillBuffer(cb, arena.handle, 0, VK_WHOLE_SIZE, 0);
+        if (autoExposure) vkCmdFillBuffer(cb, expState.handle, 0, VK_WHOLE_SIZE, 0x3F800000u);   // 1.0 until the first measurement
         memoryBarrier(cb, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_ACCESS_TRANSFER_WRITE_BIT,
                       VK_ACCESS_TRANSFER_WRITE_BIT);
         // the head weights into the arena (the reconstruction kernel reads them there)
@@ -450,9 +538,22 @@ struct EEngine::Impl {
         std::memcpy(paramStaging.data() + finAt, finBlock.data(), finBlock.size());
         for (VkDeviceSize a = 0; a < paramBytes; a += 65536)
             vkCmdUpdateBuffer(cb, params.handle, a, std::min<VkDeviceSize>(65536, paramBytes - a), paramStaging.data() + a);
+        if (autoExposure) vkCmdUpdateBuffer(cb, expP.handle, 0, sizeof(ExposureParams), &exposure);
         memoryBarrier(cb, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT, VK_ACCESS_TRANSFER_WRITE_BIT,
                       VK_ACCESS_SHADER_READ_BIT | VK_ACCESS_SHADER_WRITE_BIT);
         pass();
+        if (autoExposure) {   // counted in the input pass's time
+            if (exposure.flags & 1u) {
+                dispatch(cb, model.exposure[0], b.exposure, exposure.blocksX, exposure.blocks / exposure.blocksX);
+                step();
+            }
+            dispatch(cb, model.exposure[1], exp1Set, 1, 1);
+            step();
+        }
+        if (b.copy && reset) {   // NGX's reset frame reads the current exposure as the previous one
+            dispatch(cb, model.exposureCopy, b.copy, 1, 1);
+            step();
+        }
         dispatch(cb, *input->pipeline, b.input[cur], (ow + 15) / 16, (oh + 15) / 16);
         step(); stamp(1); pass();
         for (unsigned s = 0; s < ENet; ++s) {
@@ -467,6 +568,8 @@ struct EEngine::Impl {
         }
         stamp(2);
         dispatch(cb, *final->pipeline, b.final[cur], finalGrid[0], finalGrid[1]);
+        // the next frame's previous exposure (the input kernel read this frame's before the network)
+        if (b.copy) dispatch(cb, model.exposureCopy, b.copy, 1, 1);
         memoryBarrier(cb, VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT, VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT | VK_PIPELINE_STAGE_TRANSFER_BIT,
                       VK_ACCESS_SHADER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT | VK_ACCESS_SHADER_WRITE_BIT | VK_ACCESS_TRANSFER_READ_BIT);
         stamp(3); pass();
@@ -474,8 +577,9 @@ struct EEngine::Impl {
         ++frame;
     }
 };
-EEngine::EEngine(EModel& model, uint32_t renderWidth, uint32_t renderHeight, uint32_t outputWidth, uint32_t outputHeight, bool hdr, bool lowResMotion)
-    : impl(std::make_unique<Impl>(*model.impl, renderWidth, renderHeight, outputWidth, outputHeight, hdr, lowResMotion)) {
+EEngine::EEngine(EModel& model, uint32_t renderWidth, uint32_t renderHeight, uint32_t outputWidth, uint32_t outputHeight, bool hdr,
+                 bool lowResMotion, bool autoExposure)
+    : impl(std::make_unique<Impl>(*model.impl, renderWidth, renderHeight, outputWidth, outputHeight, hdr, lowResMotion, autoExposure)) {
     if (!model.impl->uploaded) {}   // the caller records the model's upload before the first frame
 }
 EEngine::~EEngine() = default;

engine/sr/exposure_copy_e.comp

@@ -0,0 +1,20 @@
+#version 460
+// d4r engine, presets E and F: NGX's cuda_copy_exposure_kernel. After each frame the frame's exposure (the game's
+// 1x1 texture or the AutoExposure measurement) goes into a 1x1 half surface, which the next frame's input kernel
+// samples as the previous exposure (its texture 352; on a reset frame NGX binds the current exposure there instead,
+// so the engine copies before the input kernel too). The formatted half store truncates toward zero, like the
+// auto-exposure copy (engine/exposure_k.comp).
+layout(local_size_x = 32) in;   // one full wave32 subgroup; invocation 0 stores
+layout(set = 0, binding = 0) uniform sampler2D source;
+layout(set = 0, binding = 1, r16f) uniform writeonly image2D previous;
+float truncatedHalf(float v)
+{
+    uint bits = packHalf2x16(vec2(v, 0.0)) & 65535u;
+    if (unpackHalf2x16(bits).x > v) --bits;
+    return unpackHalf2x16(bits).x;
+}
+void main()
+{
+    if (gl_LocalInvocationID.x == 0u)
+        imageStore(previous, ivec2(0), vec4(truncatedHalf(texelFetch(source, ivec2(0), 0).r)));
+}