Mörsergranate: explosion radius in the tooltip

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/dwarf-arts.md

@@ -70,3 +70,9 @@ Mod: the construct call notes grenade, owner, landing point and radius
 (`ImpactRadius`, shared with the hit check); after `0x62d530` a disc (alpha
 0x40) with a 2 px rim (alpha 0xa0) is drawn there, without depth test, until
 the impact of that owner's grenade at that point gathers its targets.
+
+Tooltip (2026-10-26, "the skills tooltip does not show the current radius"):
+a game::Art tooltip filter adds "Explosionsradius: N" after the last value
+line of each level section (current level, and the next level's in the skill
+book), in that line's colour, from the same `ImpactRadiusAt(level)` as the
+hit check and the marker.

src/mods/dwarfarts.cpp

@@ -44,6 +44,7 @@
 #include <map>
 #include <vector>
 
+#include "game/engine/art.h"
 #include "game/engine/arts.h"
 #include "game/engine/objects.h"
 #include "game/engine/orders.h"
@@ -100,12 +101,79 @@ int32_t TypeSize(uint32_t type) {
 
 // The explosion radius of a grenade thrown by `owner` (world units; a
 // creature is hit when within it plus its own size).
-int32_t ImpactRadius(void* owner) {
-    const unsigned level = owner ? game::ArtLevel(owner, game::kArtMoerser) : 0;
+int32_t ImpactRadiusAt(unsigned level) {
     const int32_t size = TypeSize(kGrenadeImpactType);
     return static_cast<int32_t>(static_cast<float>(size) * (1.0f + kRadiusGrowth * (level / kLevelsPerStep)));
 }
 
+int32_t ImpactRadius(void* owner) {
+    return ImpactRadiusAt(owner ? game::ArtLevel(owner, game::kArtMoerser) : 0);
+}
+
+// The tooltip (game::Art::Tooltip filter, as for Kettenblitz in
+// mods/chainlightning.cpp): sections start with the level line ("Aktuelle
+// Stufe:", in the skill book also "Nächste erlernte Stufe:") followed by
+// "Name: value" lines; each section gets "Explosionsradius: N" after its last
+// value, in that line's colour.
+constexpr const wchar_t* kCurrentLevelLine = L"Aktuelle Stufe:";
+constexpr const wchar_t* kNextLevelLine = L"Nächste erlernte Stufe:";
+constexpr const wchar_t* kValueSeparator = L": ";
+constexpr size_t kColourCodeLength = 10;  // "\cAARRGGBB"
+
+std::wstring LeadingColourCodes(const std::wstring& line) {
+    size_t end = 0;
+    while (line.compare(end, 2, L"\\c") == 0 && end + kColourCodeLength <= line.size()) {
+        end += kColourCodeLength;
+    }
+    return line.substr(0, end);
+}
+
+void RewriteTooltip(const game::Art& art, void* creature, std::wstring& text) {
+    std::vector<std::wstring> lines;
+    for (size_t start = 0; start < text.size();) {
+        size_t end = text.find(L'\n', start);
+        end = end == std::wstring::npos ? text.size() : end + 1;
+        lines.push_back(text.substr(start, end - start));
+        start = end;
+    }
+    const unsigned current = game::ArtLevel(creature, art.Id());
+    std::vector<std::wstring> out;
+    unsigned level = current;
+    bool inSection = false;
+    size_t lastValue = SIZE_MAX;  // index in `out`
+    const auto closeSection = [&] {
+        if (!inSection || lastValue == SIZE_MAX) {
+            return;
+        }
+        std::wstring& after = out[lastValue];
+        const bool last = after.empty() || after.back() != L'\n';
+        if (last) {
+            after += L'\n';
+        }
+        out.insert(out.begin() + static_cast<ptrdiff_t>(lastValue) + 1,
+                   LeadingColourCodes(after) + L"Explosionsradius: " + std::to_wstring(ImpactRadiusAt(level)) +
+                       (last ? L"" : L"\n"));
+    };
+    for (const std::wstring& line : lines) {
+        const bool currentHeader = line.find(kCurrentLevelLine) != std::wstring::npos;
+        const bool nextHeader = line.find(kNextLevelLine) != std::wstring::npos;
+        if (currentHeader || nextHeader) {
+            closeSection();
+            inSection = true;
+            level = nextHeader ? current + 1 : current;
+            lastValue = SIZE_MAX;
+        } else if (inSection && line.find(kValueSeparator) != std::wstring::npos) {
+            lastValue = out.size();
+        }
+        out.push_back(line);
+    }
+    closeSection();
+    text.clear();
+    for (const std::wstring& line : out) {
+        text += line;
+    }
+}
+
 // 0x5ab400 calls 0x5ff820 (thiscall (out, position, type, only, radius),
 // ret 0x14) with the effect object in ebx.
 __declspec(naked) void GatherTargetsThunk() {
@@ -362,7 +430,10 @@ void Startup() {
 RE_STARTUP(DwarfArtsStartup, Startup);
 
 struct Registration {
-    Registration() { game::OnCreatureOrder(&OnOrder); }
+    Registration() {
+        game::OnCreatureOrder(&OnOrder);
+        game::AddTooltipFilter(game::kArtMoerser, &RewriteTooltip);
+    }
 } g_registration;
 
 } // namespace