feat(dxmt): add preferredMaxFrameRate frame pacing support to DXMT_CONFIG

dylib/feats/compat_run.sh

@@ -1025,6 +1025,31 @@ if [ "$verb" = waitforexitandrun ] && [ -f "$np_defaults_file" ] && [ -r "$np_de
         [ "${wine_unix##*/}" = aarch64-unix ] || continue ;;
       MTL_HUD_ENABLED=[01] | DXMT_ENABLE_NVEXT=[01] | DXMT_METALFX_SPATIAL_SWAPCHAIN=[01] | \
       WINEMSYNC=[01] | NOTPROTON_RETINA=[01] | NOTPROTON_RAW_CONTROLLERS=[01] | NOTPROTON_DISABLE_HIDRAW=[01]) ;;
+      DXMT_CONFIG=*\;*)
+        dxmt_added=""
+        old_ifs=$IFS; IFS=";"
+        set -f
+        for clause in $value; do
+          case "$clause" in d3d11.metalSpatialUpscaleFactor=*)
+            case "${clause#*=}" in 1.5 | 1.72 | 2.0 | 3.0) ;; *) continue ;; esac
+            if ! printf '%s' "${DXMT_CONFIG-}" | tr ';' '\n' \
+              | grep -q '^[[:space:]]*d3d11\.metalSpatialUpscaleFactor[[:space:]]*='; then
+              export DXMT_CONFIG="${DXMT_CONFIG:+$DXMT_CONFIG;}$clause"
+              dxmt_added="${dxmt_added:+$dxmt_added;}$clause"
+            fi ;;
+          d3d11.preferredMaxFrameRate=*)
+            case "${clause#*=}" in 30 | 40 | 60 | 120 | 144) ;; *) continue ;; esac
+            if ! printf '%s' "${DXMT_CONFIG-}" | tr ';' '\n' \
+              | grep -q '^[[:space:]]*d3d11\.preferredMaxFrameRate[[:space:]]*='; then
+              export DXMT_CONFIG="${DXMT_CONFIG:+$DXMT_CONFIG;}$clause"
+              dxmt_added="${dxmt_added:+$dxmt_added;}$clause"
+            fi ;; esac
+        done
+        set +f; IFS=$old_ifs
+        if [ -n "$dxmt_added" ]; then
+          np_defaulted="$np_defaulted${np_defaulted:+ }DXMT_CONFIG=$dxmt_added"
+        fi
+        continue ;;
       DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=*)
         case "${value#*=}" in 1.5 | 1.72 | 2.0 | 3.0) ;; *) continue ;; esac
         if printf '%s' "${DXMT_CONFIG-}" | tr ';' '\n' \
@@ -1034,6 +1059,15 @@ if [ "$verb" = waitforexitandrun ] && [ -f "$np_defaults_file" ] && [ -r "$np_de
         export DXMT_CONFIG="${DXMT_CONFIG:+$DXMT_CONFIG;}$value"
         np_defaulted="$np_defaulted${np_defaulted:+ }$line"
         continue ;;
+      DXMT_CONFIG=d3d11.preferredMaxFrameRate=*)
+        case "${value#*d3d11.preferredMaxFrameRate=}" in 30 | 40 | 60 | 120 | 144) ;; *) continue ;; esac
+        if printf '%s' "${DXMT_CONFIG-}" | tr ';' '\n' \
+          | grep -q '^[[:space:]]*d3d11\.preferredMaxFrameRate[[:space:]]*='; then
+          continue
+        fi
+        export DXMT_CONFIG="${DXMT_CONFIG:+$DXMT_CONFIG;}$value"
+        np_defaulted="$np_defaulted${np_defaulted:+ }$line"
+        continue ;;
       *) continue ;;
     esac
     eval "[ -z \"\${$key+x}\" ]" || continue

dylib/feats/defaults.c

@@ -21,6 +21,7 @@ static const char *const g_bools[]    = { "0", "1", NULL };
 static const char *const g_backends[] = { "dxmt", "dxvk", "wined3d", NULL };
 static const char *const g_d3dmetal[] = { "d3dmetal", NULL };
 static const char *const g_factors[]  = { "1.5", "1.72", "2.0", "3.0", NULL };
+static const char *const g_fps[]      = { "30", "40", "60", "120", "144", NULL };
 
 static const struct {
     const char        *key;
@@ -56,7 +57,38 @@ static int is_one_of(const char *const *list, const char *v, size_t len) {
     return 0;
 }
 
+#define FACTOR_PREFIX "d3d11.metalSpatialUpscaleFactor="
+#define FPS_PREFIX    "d3d11.preferredMaxFrameRate="
+
+static int valid_dxmt_config(const char *v, size_t len) {
+    if (len == 0 || v[0] == ';' || v[len - 1] == ';') return 0;
+    const size_t factor_pre = sizeof(FACTOR_PREFIX) - 1;
+    const size_t fps_pre = sizeof(FPS_PREFIX) - 1;
+    int seen_factor = 0, seen_fps = 0;
+    size_t at = 0;
+    while (at < len) {
+        const char *semi = memchr(v + at, ';', len - at);
+        size_t n = semi ? (size_t)(semi - (v + at)) : len - at;
+        if (n == 0) return 0;
+        const char *clause = v + at;
+
+        if (n > factor_pre && memcmp(clause, FACTOR_PREFIX, factor_pre) == 0) {
+            if (seen_factor || !is_one_of(g_factors, clause + factor_pre, n - factor_pre)) return 0;
+            seen_factor = 1;
+        } else if (n > fps_pre && memcmp(clause, FPS_PREFIX, fps_pre) == 0) {
+            if (seen_fps || !is_one_of(g_fps, clause + fps_pre, n - fps_pre)) return 0;
+            seen_fps = 1;
+        } else {
+            return 0;
+        }
+        at += n + (semi ? 1 : 0);
+    }
+    return seen_factor || seen_fps;
+}
+
 static int valid_value(size_t i, uint32_t runner, const char *v, size_t len) {
+    if (is(g_settings[i].key, strlen(g_settings[i].key), "DXMT_CONFIG"))
+        return valid_dxmt_config(v, len);
     size_t pre = strlen(g_settings[i].prefix);
     if (len <= pre || memcmp(v, g_settings[i].prefix, pre) != 0) return 0;
     return is_one_of(g_settings[i].values, v + pre, len - pre)

dylib/feats/webpatch.c

@@ -1219,6 +1219,7 @@ static int out_expand(np_out_t *o, const char *replace, const np_cap_t *caps) {
 #define NP_CX_BARREL_READY(B) "[" NP_CX_BARREL(NP_CX_BARREL_JS) "].every(n=>" B "[n])"
 
 #define NP_CX_FACTOR_ENTRY "e=>/^[ \\t\\r]*d3d11\\.metalSpatialUpscaleFactor[ \\t\\r]*=/.test(e)"
+#define NP_CX_FPS_ENTRY    "e=>/^[ \\t\\r]*d3d11\\.preferredMaxFrameRate[ \\t\\r]*=/.test(e)"
 
 #define NP_CX_DEFAULTS "(globalThis.MSCXDefaultsData||(globalThis.MSCXDefaultsData=" NP_DEFAULTS "))"
 #define NP_CX_BUILDS "(globalThis.MSCXBuilds||(globalThis.MSCXBuilds=" NP_BUILDS "))"
@@ -1343,23 +1344,35 @@ static int out_expand(np_out_t *o, const char *replace, const np_cap_t *caps) {
     "dx=\"\"===b||\"dxmt\"===b," \
     "sw=\"1\"===G(\"DXMT_METALFX_SPATIAL_SWAPCHAIN\")," \
     "F=\"d3d11.metalSpatialUpscaleFactor=\",fk=" NP_CX_FACTOR_ENTRY "," \
+    "FP=\"d3d11.preferredMaxFrameRate=\",fpk=" NP_CX_FPS_ENTRY "," \
     "fe=readSaved(\"DXMT_CONFIG\").split(\";\").filter(e=>e.trim())," \
     "fx=v=>fe.filter(e=>!fk(e)).concat(v?[F+v]:[]).join(\";\")," \
+    "fxFps=v=>fe.filter(e=>!fpk(e)).concat(v?[FP+v]:[]).join(\";\")," \
     "pf=c=>{const v=(c.split(\";\").filter(fk).pop()||\"=2\").replace(/^[^=]*=/,\"\").replace(/\"/g,\"\").trim().split(/\\s/)[0];" \
     "return Math.max(isNaN(+v)?2:+v,1)}," \
+    "pfp=c=>{const v=(c.split(\";\").filter(fpk).pop()||\"\").replace(/^[^=]*=/,\"\").replace(/\"/g,\"\").trim().split(/\\s/)[0];" \
+    "return 0===+v?\"\":v}," \
     "fn=pf(G(\"DXMT_CONFIG\"))," \
+    "fnFps=pfp(G(\"DXMT_CONFIG\"))," \
     "U=[{data:\"\",label:npL(\"Off\",\"关闭\",\"Disattivato\")}," \
     "{data:\"1.5\",label:\"1.5x\"}," \
     "{data:\"1.72\",label:\"1.72x\"}," \
     "{data:\"2.0\",label:\"2x\"}," \
     "{data:\"3.0\",label:\"3x\"}]," \
+    "FPS=[{data:\"\",label:npL(\"Off\",\"关闭\",\"Disattivato\")}," \
+    "{data:\"30\",label:\"30 FPS\"}," \
+    "{data:\"40\",label:\"40 FPS\"}," \
+    "{data:\"60\",label:\"60 FPS\"}," \
+    "{data:\"120\",label:\"120 FPS\"}," \
+    "{data:\"144\",label:\"144 FPS\"}]," \
     "B=[{data:\"\",label:npL(\"Automatic\",\"自动\",\"Automatico\")}," \
     "{data:\"d3dmetal\",label:\"D3DMetal\"}," \
     "{data:\"dxmt\",label:\"DXMT\"}," \
     "{data:\"dxvk\",label:\"DXVK\"}," \
     "{data:\"wined3d\",label:\"WineD3D\"}].filter(x=>!fex||x.data!==\"d3dmetal\")," \
     "pick=f=>\"1\"===f(\"DXMT_METALFX_SPATIAL_SWAPCHAIN\")?(U.find(u=>u.data&&+u.data===pf(f(\"DXMT_CONFIG\")||\"\"))" \
-    "||{data:String(pf(f(\"DXMT_CONFIG\")||\"\"))}).data:\"\";" \
+    "||{data:String(pf(f(\"DXMT_CONFIG\")||\"\"))}).data:\"\"," \
+    "pickFps=f=>pfp(f(\"DXMT_CONFIG\")||\"\");" \
     /* Without our run script behind it a row can only be what a launch option can carry,
        so one asking for a staged DLL or an override is not offered, and neither is one
        with nothing to deliver. */ \
@@ -1392,6 +1405,14 @@ static int out_expand(np_out_t *o, const char *replace, const np_cap_t *caps) {
     "onChange:v=>s(dflt&&v.data===pick(k=>dflt(k)||\"\")" \
     "?[[\"DXMT_METALFX_SPATIAL_SWAPCHAIN\",\"\"],[\"DXMT_CONFIG\",fx(\"\")]]" \
     ":[[\"DXMT_METALFX_SPATIAL_SWAPCHAIN\",v.data?\"1\":\"0\"],[\"DXMT_CONFIG\",fx(v.data)]])})},\"usf\")," \
+    "ours&&dx&&(0," RT ".jsx)(" BARREL ".XY," \
+    "{label:npL(\"DXMT Frame Rate Limit\"," \
+    "\"DXMT Frame Rate Limit\",\"DXMT Frame Rate Limit\")," \
+    "children:(0," RT ".jsx)(" BARREL ".m,{rgOptions:FPS," \
+    "selectedOption:(FPS.find(u=>u.data===fnFps)||{data:fnFps}).data," \
+    "onChange:v=>s(dflt&&v.data===pickFps(k=>dflt(k)||\"\")" \
+    "?[[\"DXMT_CONFIG\",fxFps(\"\")]]" \
+    ":[[\"DXMT_CONFIG\",fxFps(v.data||(dflt?\"0\":\"\"))]])})},\"fps\")," \
     "ours&&(0," RT ".jsxs)(" BARREL ".XY,{label:npL(\"Controllers\",\"控制器\",\"Controller\"),children:[" \
     "T(\"NOTPROTON_RAW_CONTROLLERS\",npL(\"Let Games Read Controllers Directly (May break Steam Input. Not recommended)\"," \
     "\"允许游戏直接读取控制器（可能导致 Steam Input 失效，不推荐）\"," \
@@ -1428,9 +1449,11 @@ static int out_expand(np_out_t *o, const char *replace, const np_cap_t *caps) {
     "fex=" NP_FEX_TOOLS ".indexOf(tn)>=0," \
     "L=MSCXLaunch(o,t.unAppID),g=L.g,has=k=>L.k.includes(k)," \
     "lost=globalThis.MSCXDefaultsLost,DF=lost?{}:(" NP_CX_BUILDS ".find(x=>x.id===tn)||{}).override||" NP_CX_DEFAULTS "[fex?\"fex\":\"rosetta\"]||{}," \
-    "fk=" NP_CX_FACTOR_ENTRY "," \
+    "fk=" NP_CX_FACTOR_ENTRY ",fpk=" NP_CX_FPS_ENTRY "," \
     "own=g(\"DXMT_CONFIG\").split(\";\").filter(e=>e.trim())," \
-    "G=k=>\"DXMT_CONFIG\"===k?(own.some(fk)?g(k):DF[k]||\"\"):has(k)?g(k):DF[k]||\"\";" \
+    "dfe=(DF[\"DXMT_CONFIG\"]||\"\").split(\";\").filter(e=>e.trim())," \
+    "mergedDxmt=[own.filter(fk).pop()||dfe.filter(fk).pop(),own.filter(fpk).pop()||dfe.filter(fpk).pop()].concat(own.filter(e=>!fk(e)&&!fpk(e))).filter(Boolean).join(\";\")," \
+    "G=k=>\"DXMT_CONFIG\"===k?mergedDxmt:has(k)?g(k):DF[k]||\"\";" \
     "if(t.unAppID<2147483648&&(t.vecPlatforms||[]).indexOf(\"osx\")>=0" \
     "&&!t.strCompatToolName)return null;" \
     "return MSCXPanel({fex,get:G,saved:g,set:L.s,clearUnused:1,dev:1,tool:tn," \

dylib/tests/defaults-check.c

@@ -90,11 +90,23 @@ static void valid_cases(void) {
           "a row takes only 0 or 1");
     check(valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1.72"),
           "DXMT_CONFIG takes a factor");
+    check(valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=60") &&
+          valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=144"),
+          "DXMT_CONFIG takes a frame rate");
+    check(valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1.5;d3d11.preferredMaxFrameRate=60") &&
+          valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=120;d3d11.metalSpatialUpscaleFactor=2.0"),
+          "DXMT_CONFIG takes both factor and frame rate in either order");
     check(!valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=") &&
           !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=.") &&
           !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1;x=1") &&
           !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1234567") &&
-          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=60"),
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=0") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=15") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=60;d3d11.preferredMaxFrameRate=30") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1.5;d3d11.metalSpatialUpscaleFactor=2.0") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=;d3d11.preferredMaxFrameRate=60") &&
+          !valid(NP_DEFAULTS_ROSETTA, "DXMT_CONFIG=d3d11.preferredMaxFrameRate=60;"),
           "DXMT_CONFIG takes nothing else");
     check(!valid(NP_DEFAULTS_ROSETTA, "WINEDEBUG=+all") && !valid(2, "WINEMSYNC=1"),
           "other keys and runners are refused");

dylib/tests/envcheck.sh

@@ -232,10 +232,32 @@ eval "$defaults"
 is "the game's factor wins" "a=1; d3d11.metalSpatialUpscaleFactor = 3.0" "$DXMT_CONFIG"
 clear
 cp "$np_support/defaults-rosetta" "$work/rosetta.keep"
-printf 'DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=.\nDXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1234567\nDXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=\n' \
+printf 'DXMT_CONFIG=d3d11.preferredMaxFrameRate=60\n' > "$np_support/defaults-rosetta"
+eval "$defaults"
+is "a defaulted frame rate is the DXMT_CONFIG" "d3d11.preferredMaxFrameRate=60" "${DXMT_CONFIG-}"
+clear
+export DXMT_CONFIG="d3d11.preferredMaxFrameRate=120"
+eval "$defaults"
+is "the game's frame rate wins over the default" "d3d11.preferredMaxFrameRate=120" "$DXMT_CONFIG"
+clear
+export DXMT_CONFIG="d3d11.preferredMaxFrameRate=0"
+eval "$defaults"
+is "a game that turned the limit off keeps it off" "d3d11.preferredMaxFrameRate=0" "$DXMT_CONFIG"
+clear
+printf 'DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=2.0;d3d11.preferredMaxFrameRate=60\n' > "$np_support/defaults-rosetta"
+eval "$defaults"
+is "both factor and frame rate are applied from combined defaults" \
+  "d3d11.metalSpatialUpscaleFactor=2.0;d3d11.preferredMaxFrameRate=60" "$DXMT_CONFIG"
+clear
+export DXMT_CONFIG="d3d11.preferredMaxFrameRate=30"
+eval "$defaults"
+is "the game's frame rate wins and default factor joins" \
+  "d3d11.preferredMaxFrameRate=30;d3d11.metalSpatialUpscaleFactor=2.0" "$DXMT_CONFIG"
+clear
+printf 'DXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=.\nDXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=1234567\nDXMT_CONFIG=d3d11.metalSpatialUpscaleFactor=\nDXMT_CONFIG=d3d11.preferredMaxFrameRate=abc\nDXMT_CONFIG=d3d11.preferredMaxFrameRate=0\n' \
   > "$np_support/defaults-rosetta"
 eval "$defaults"
-is "factors the Settings page would refuse are skipped" "unset" "${DXMT_CONFIG-unset}"
+is "factors and frame rates the Settings page would refuse are skipped" "unset" "${DXMT_CONFIG-unset}"
 mv "$work/rosetta.keep" "$np_support/defaults-rosetta"
 
 clear

dylib/tests/panel-behavior/behavior.js

@@ -128,16 +128,16 @@ for (const form of Object.keys(FORMS)) {
   }
 
   let r = nodes('');
-  t.ok(toggles(r).length === 7 && sections(r).length === 4, 'automatic shows seven toggles in four sections');
-  t.ok(r.filter(x => x.type === 'Dropdown').length === 2, 'two dropdowns');
+  t.ok(toggles(r).length === 7 && sections(r).length === 5, 'automatic shows seven toggles in five sections');
+  t.ok(r.filter(x => x.type === 'Dropdown').length === 3, 'three dropdowns');
   t.ok(!('label' in r.find(x => x.type === 'Dropdown').props), 'the backend dropdown carries no label column');
 
   r = nodes('CX_GRAPHICS_BACKEND=dxmt');
-  t.ok(toggles(r).filter(l => l === 'DLSS').length === 1 && sections(r).includes('MetalFX'),
-       'dxmt keeps one DLSS and keeps MetalFX');
+  t.ok(toggles(r).filter(l => l === 'DLSS').length === 1 && sections(r).includes('MetalFX') && sections(r).includes('DXMT'),
+       'dxmt keeps one DLSS and keeps MetalFX and DXMT sections');
   r = nodes('CX_GRAPHICS_BACKEND=d3dmetal');
-  t.ok(toggles(r).filter(l => l === 'DLSS').length === 1 && !sections(r).includes('MetalFX'),
-       'd3dmetal keeps one DLSS and hides MetalFX');
+  t.ok(toggles(r).filter(l => l === 'DLSS').length === 1 && !sections(r).includes('MetalFX') && !sections(r).includes('DXMT'),
+       'd3dmetal keeps one DLSS and hides MetalFX and DXMT sections');
   // Both flags are labeled DLSS, so a backend showing its own and its neighbor's
   // would put the same word on two rows.
   for (const b of ['', 'd3dmetal', 'dxmt', 'dxvk', 'wined3d']) {
@@ -165,6 +165,36 @@ for (const form of Object.keys(FORMS)) {
   nodes('CX_GRAPHICS_BACKEND=dxmt').filter(x => x.type === 'Dropdown')[1].props.onChange({ data: '2.0' });
   t.ok(last().includes('metalSpatialUpscaleFactor=2.0'), 'the upscaler writes its factor');
 
+  nodes('CX_GRAPHICS_BACKEND=dxmt').filter(x => x.type === 'Dropdown')[2].props.onChange({ data: '60' });
+  t.ok(last().includes('preferredMaxFrameRate=60'), 'the frame rate limiter writes its FPS');
+
+  nodes('CX_GRAPHICS_BACKEND=dxmt DXMT_CONFIG="d3d11.metalSpatialUpscaleFactor=2.0"').filter(x => x.type === 'Dropdown')[2].props.onChange({ data: '120' });
+  t.ok(last().includes('metalSpatialUpscaleFactor=2.0') && last().includes('preferredMaxFrameRate=120'),
+       'the frame rate limiter preserves upscale factor');
+
+  nodes('CX_GRAPHICS_BACKEND=dxmt DXMT_CONFIG="d3d11.metalSpatialUpscaleFactor=2.0;d3d11.preferredMaxFrameRate=60"').filter(x => x.type === 'Dropdown')[2].props.onChange({ data: '' });
+  t.ok(last().includes('metalSpatialUpscaleFactor=2.0') && !last().includes('preferredMaxFrameRate'),
+       'turning off frame rate limiter keeps upscale factor');
+
+  {
+    const capped = { document: { documentElement: { lang: 'en' } },
+                     MSCXDefaultsData: { rosetta: { DXMT_CONFIG: 'd3d11.preferredMaxFrameRate=60' }, fex: {} } };
+    const { render: PC, written: cw } = panel(emit, form, capped);
+    const fps = opts => walk(PC({ details: details(opts + ' %command%') }))
+      .filter(x => x.type === 'Dropdown')[2];
+    t.ok(fps('CX_GRAPHICS_BACKEND=dxmt').props.selectedOption === '60', 'a game shows the default frame rate');
+    fps('CX_GRAPHICS_BACKEND=dxmt').props.onChange({ data: '' });
+    const off = cw[cw.length - 1].opts;
+    t.ok(off.includes('preferredMaxFrameRate=0'), `turning the limit off writes 0 over the default (${off})`);
+    t.ok(fps(off.replace(/ ?%command%$/, '')).props.selectedOption === '', 'and reads back as off');
+    fps('CX_GRAPHICS_BACKEND=dxmt DXMT_CONFIG="d3d11.preferredMaxFrameRate=0"').props.onChange({ data: '60' });
+    t.ok(!cw[cw.length - 1].opts.includes('DXMT_CONFIG'), 'picking the default again drops the clause');
+  }
+
+  const fpsOptions = nodes('CX_GRAPHICS_BACKEND=dxmt').filter(x => x.type === 'Dropdown')[2]
+    .props.rgOptions.map(o => o.data);
+  t.ok(fpsOptions.join(',') === ',30,40,60,120,144', `the fps options are available (${fpsOptions.join(',')})`);
+
   // The section names the factor, so a label promising a resolution to go and set in
   // the game is the wording this replaced.
   const upscaler = nodes('CX_GRAPHICS_BACKEND=dxmt').find(x => x.type === 'Section' &&