Scale geomod crater texture PPM based on its resolution

docs/CHANGELOG.md

@@ -44,6 +44,7 @@ Version 1.9.0 (not released yet)
 - Add level filename to "Level Initializing" console message
 - Properly handle WM_PAINT in dedicated server, may improve performance (DF bug)
 - Fix crash when `verify_level` command is run without a level being loaded
+- Add correct scaling for geomod crater texture based on resolution
 
 Version 1.8.0 (released 2022-09-17)
 -----------------------------------

game_patch/bmpman/bmpman.h

@@ -4,6 +4,13 @@
 #include "../rf/bmpman.h"
 #include "../rf/gr/gr.h"
 
+namespace rf
+{
+    static auto& bm_bitmaps = addr_as_ref<void*>(0x017C80C4);
+    static auto& bm_get_cache_slot = addr_as_ref<int(int)>(0x0050F440);
+    static auto& geomod_crater_texture_handle = addr_as_ref<int>(0x00646000);
+}
+
 void bm_set_dynamic(int bm_handle, bool dynamic);
 bool bm_is_dynamic(int bm_handle);
 void bm_change_format(int bm_handle, rf::bm::Format format);

game_patch/misc/g_solid.cpp

@@ -1,4 +1,5 @@
 #include <patch_common/FunHook.h>
+#include <patch_common/CallHook.h>
 #include <patch_common/CodeInjection.h>
 #include <patch_common/AsmWriter.h>
 #include <xlog/xlog.h>
@@ -409,6 +410,53 @@ void g_solid_render_ui()
     }
 }
 
+std::optional<int> bm_get_cache_slot_opt(int handle)
+{
+    int cache_slot = rf::bm_get_cache_slot(handle);
+    return (cache_slot == -1) ? std::nullopt : std::optional<int>{cache_slot};
+}
+
+int bm_get_width(int handle)
+{
+    auto cache_slot = bm_get_cache_slot_opt(handle).value_or(0);
+    if (cache_slot == 0) {
+        return 0;
+    }
+    int index = 27 * cache_slot;
+    return *((uint16_t*)rf::bm_bitmaps + 2 * index + 22);
+}
+
+int bm_get_height(int handle)
+{
+    auto cache_slot = bm_get_cache_slot_opt(handle).value_or(0);
+    if (cache_slot == 0) {
+        return 0;
+    }
+    int index = 27 * cache_slot;
+    return *((uint16_t*)rf::bm_bitmaps + 2 * index + 23);
+}
+
+float bm_calculate_ppm(int handle)
+{
+    const int width = bm_get_width(handle);
+    const int height = bm_get_height(handle);
+
+    if (width <= 0 || height <= 0) {
+        // something weird happened, use default value and avoid divide by zero
+        return 32.0f;
+    }
+
+    const float max_dimension = static_cast<float>(std::max(width, height));
+    return 32.0f * (max_dimension / 256.0f);
+}
+
+using GSolid_SetAutotexture_Type = void __fastcall(rf::GSolid*, float);
+CallHook<GSolid_SetAutotexture_Type> set_geo_crater_ppm_hook{
+    0x00466BD4, [](rf::GSolid* solid, float ppm) {      
+        set_geo_crater_ppm_hook.call_target(solid, bm_calculate_ppm(rf::geomod_crater_texture_handle));
+    }
+};
+
 void g_solid_do_patch()
 {
     // Buffer overflows in solid_read
@@ -465,6 +513,9 @@ void g_solid_do_patch()
     AsmWriter{0x004D4409}.jmp(0x004D44B1);
     AsmWriter{0x004D44C7}.nop(2);
 
+    // Set PPM for geo crater texture based on its resolution instead of static value of 32.0
+    set_geo_crater_ppm_hook.install();
+
     // Commands
     max_decals_cmd.register_cmd();
     dbg_room_clip_wnd_cmd.register_cmd();