diff --git a/CMakeLists.txt b/CMakeLists.txt
index a3d0918..295cb6f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,8 @@ if(WHOA_STORM_FLAVOR STREQUAL "SC1")
     if (WHOA_SYSTEM_MAC OR WHOA_SYSTEM_LINUX)
         add_definitions(-DWHOA_STORM_C_CRIT_SECT_RECURSIVE)
     endif()
+
+    add_definitions(-DWHOA_RECT_USES_SCREEN_COORDINATES)
 elseif(WHOA_STORM_FLAVOR STREQUAL "WOW")
     message(STATUS "Building Storm with World of Warcraft flavoring")
 else()
diff --git a/storm/Region.cpp b/storm/Region.cpp
index 537e0d5..9f1ad53 100644
--- a/storm/Region.cpp
+++ b/storm/Region.cpp
@@ -27,10 +27,17 @@ void AddSourceRect(TSGrowableArray<SOURCE>* sourceArray, const RECTF* rect, void
 }
 
 int32_t CheckForIntersection(const RECTF* sourceRect, const RECTF* targetRect) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+    return sourceRect->left < targetRect->right
+        && sourceRect->top < targetRect->bottom
+        && sourceRect->right > targetRect->left
+        && sourceRect->bottom > targetRect->top;
+#else
     return sourceRect->left < targetRect->right
         && sourceRect->bottom < targetRect->top
         && sourceRect->right > targetRect->left
         && sourceRect->top > targetRect->bottom;
+#endif
 }
 
 void CombineRectangles(TSGrowableArray<RECTF>* combinedArray) {
@@ -41,12 +48,18 @@ void CombineRectangles(TSGrowableArray<RECTF>* combinedArray) {
 
             if (rctA->left == rctB->left && rctA->right == rctB->right) {
                 if (rctA->bottom == rctB->top || rctB->bottom == rctA->top) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+                    rctA->top = std::min(rctB->top, rctA->top);
+                    rctA->bottom = std::max(rctB->bottom, rctA->bottom);
+#else
                     rctA->bottom = std::min(rctB->bottom, rctA->bottom);
                     rctA->top = std::max(rctB->top, rctA->top);
+#endif
                     DeleteRect(rctB);
                     break;
                 }
             }
+
             if (rctA->left == rctB->right || rctB->left == rctA->right) {
                 if (rctA->bottom == rctB->bottom && rctA->top == rctB->top) {
                     rctA->left = std::min(rctB->left, rctA->left);
@@ -57,9 +70,23 @@ void CombineRectangles(TSGrowableArray<RECTF>* combinedArray) {
             }
 
             if (rctA->left == rctB->right || rctB->left == rctA->right) {
-                if (rctA->bottom < rctB->top && rctB->bottom < rctA->top) {
-                    RECTF newrect[5];
+                RECTF newrect[5];
 
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+                if (rctA->top < rctB->bottom && rctB->top < rctA->bottom) {
+                    newrect[0] = { rctA->left, rctA->top, rctA->right, rctB->top };
+                    newrect[1] = { rctB->left, rctB->top, rctB->right, rctA->top };
+                    newrect[2] = { rctA->left, rctB->bottom, rctA->right, rctA->bottom };
+                    newrect[3] = { rctB->left, rctA->bottom, rctB->right, rctB->bottom };
+
+                    newrect[4] = {
+                        std::min(rctB->left, rctA->left),
+                        std::max(rctB->top, rctA->top),
+                        std::max(rctB->right, rctA->right),
+                        std::min(rctB->bottom, rctA->bottom)
+                    };
+#else
+                if (rctA->bottom < rctB->top && rctB->bottom < rctA->top) {
                     newrect[0] = { rctA->left, rctA->bottom, rctA->right, rctB->bottom };
                     newrect[1] = { rctB->left, rctB->bottom, rctB->right, rctA->bottom };
                     newrect[2] = { rctA->left, rctB->top, rctA->right, rctA->top };
@@ -71,6 +98,7 @@ void CombineRectangles(TSGrowableArray<RECTF>* combinedArray) {
                         std::max(rctB->right, rctA->right),
                         std::min(rctB->top, rctA->top)
                     };
+#endif
 
                     for (uint32_t k = 0; k < 5; k++) {
                         if (!IsNullRect(&newrect[k])) {
@@ -163,6 +191,23 @@ void FragmentCombinedRectangles(TSGrowableArray<RECTF>* combinedArray, uint32_t
     }
 
     RECTF newrect[4];
+
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+    newrect[0] = { rect->left, rect->top, rect->right, checkRect->top };
+    newrect[1] = { rect->left, checkRect->bottom, rect->right, rect->bottom };
+    newrect[2] = {
+        rect->left,
+        std::max(checkRect->top, rect->top),
+        checkRect->left,
+        std::min(checkRect->bottom, rect->bottom)
+    };
+    newrect[3] = {
+        checkRect->right,
+        std::max(checkRect->top, rect->top),
+        rect->right,
+        std::min(checkRect->bottom, rect->bottom)
+    };
+#else
     newrect[0] = { rect->left, rect->bottom, rect->right, checkRect->bottom };
     newrect[1] = { rect->left, checkRect->top, rect->right, rect->top };
     newrect[2] = {
@@ -177,6 +222,7 @@ void FragmentCombinedRectangles(TSGrowableArray<RECTF>* combinedArray, uint32_t
         rect->right,
         std::min(checkRect->top, rect->top)
     };
+#endif
 
     for (uint32_t i = 0; i < 4; i++) {
         if (!IsNullRect(&newrect[i])) {
@@ -211,6 +257,42 @@ void FragmentSourceRectangles(TSGrowableArray<SOURCE>* sourceArray, uint32_t fir
 
             RECTF newRect[5];
 
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+            newRect[0] = {
+                overlapRect[minTop]->left,
+                overlapRect[minTop]->top,
+                overlapRect[minTop]->right,
+                overlapRect[maxTop]->top,
+            };
+
+            newRect[1] = {
+                overlapRect[maxBottom]->left,
+                overlapRect[minBottom]->bottom,
+                overlapRect[maxBottom]->right,
+                overlapRect[maxBottom]->bottom,
+            };
+
+            newRect[2] = {
+                overlapRect[minLeft]->left,
+                overlapRect[maxTop]->top,
+                overlapRect[maxLeft]->left,
+                overlapRect[minBottom]->bottom,
+            };
+
+            newRect[3] = {
+                overlapRect[minRight]->right,
+                overlapRect[maxTop]->top,
+                overlapRect[maxRight]->right,
+                overlapRect[minBottom]->bottom,
+            };
+
+            newRect[4] = {
+                overlapRect[maxLeft]->left,
+                overlapRect[maxTop]->top,
+                overlapRect[minRight]->right,
+                overlapRect[minBottom]->bottom,
+            };
+#else
             newRect[0] = {
                 overlapRect[minBottom]->left,
                 overlapRect[minBottom]->bottom,
@@ -245,6 +327,7 @@ void FragmentSourceRectangles(TSGrowableArray<SOURCE>* sourceArray, uint32_t fir
                 overlapRect[minRight]->right,
                 overlapRect[minTop]->top,
             };
+#endif
 
             int32_t overlaps[5][2];
             for (uint32_t j = 0; j < 5; j++) {
@@ -287,7 +370,11 @@ void FragmentSourceRectangles(TSGrowableArray<SOURCE>* sourceArray, uint32_t fir
 }
 
 int32_t IsNullRect(const RECTF* rect) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+    return rect->left >= rect->right || rect->top >= rect->bottom;
+#else
     return rect->left >= rect->right || rect->bottom >= rect->top;
+#endif
 }
 
 void ClearRegion(RGN* rgn) {
@@ -522,10 +609,12 @@ void SRgnGetBoundingRectf(HSRGN handle, RECTF* rect) {
     STORM_VALIDATE(rect);
     STORM_VALIDATE_END_VOID;
 
-    rect->left = std::numeric_limits<float>::max();
-    rect->bottom = std::numeric_limits<float>::max();
-    rect->right = std::numeric_limits<float>::min();
-    rect->top = std::numeric_limits<float>::min();
+    *rect = {
+        std::numeric_limits<float>::max(),
+        std::numeric_limits<float>::max(),
+        std::numeric_limits<float>::min(),
+        std::numeric_limits<float>::min(),
+    };
 
     HLOCKEDRGN lockedHandle;
     auto rgn = s_rgntable.Lock(handle, &lockedHandle, 0);
@@ -538,9 +627,15 @@ void SRgnGetBoundingRectf(HSRGN handle, RECTF* rect) {
 
         if (!(source->flags & SF_PARAMONLY)) {
             rect->left = std::min(source->rect.left, rect->left);
-            rect->bottom = std::min(source->rect.bottom, rect->bottom);
             rect->right = std::max(source->rect.right, rect->right);
+
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+            rect->top = std::min(source->rect.top, rect->top);
+            rect->bottom = std::max(source->rect.bottom, rect->bottom);
+#else
+            rect->bottom = std::min(source->rect.bottom, rect->bottom);
             rect->top = std::max(source->rect.top, rect->top);
+#endif
         }
     }
 
@@ -562,11 +657,16 @@ void SRgnGetBoundingRecti(HSRGN handle, RECT* rect) {
     RECTF rectf;
     SRgnGetBoundingRectf(handle, &rectf);
 
-    // NOTE: top and bottom get flipped, this is a bug in Storm
     rect->left = static_cast<int32_t>(rectf.left);
-    rect->top = static_cast<int32_t>(rectf.bottom);
     rect->right = static_cast<int32_t>(rectf.right);
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+    rect->top = static_cast<int32_t>(rectf.top);
+    rect->bottom = static_cast<int32_t>(rectf.bottom);
+#else
+    // NOTE: top and bottom get flipped, this is a bug in Storm
+    rect->top = static_cast<int32_t>(rectf.bottom);
     rect->bottom = static_cast<int32_t>(rectf.top);
+#endif
 }
 
 void SRgnGetRectParamsf(HSRGN handle, const RECTF* rect, uint32_t* numParams, void** buffer) {
@@ -659,13 +759,18 @@ void SRgnGetRectsi(HSRGN handle, uint32_t* numRects, RECT* buffer) {
     SRgnGetRectsf(handle, numRects, bufferf);
     if (buffer) {
         for (uint32_t i = 0; i < *numRects; i++) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+            buffer[i].top = static_cast<int32_t>(bufferf[i].top);
+            buffer[i].bottom = static_cast<int32_t>(bufferf[i].bottom);
+#else
             float bottom = bufferf[i].bottom;
             float top = bufferf[i].top;
 
-            buffer[i].left = static_cast<int32_t>(bufferf[i].left);
             buffer[i].bottom = static_cast<int32_t>(bottom);
-            buffer[i].right = static_cast<int32_t>(bufferf[i].right);
             buffer[i].top = static_cast<int32_t>(top);
+#endif
+            buffer[i].left = static_cast<int32_t>(bufferf[i].left);
+            buffer[i].right = static_cast<int32_t>(bufferf[i].right);
         }
     }
 }
@@ -687,8 +792,13 @@ int32_t SRgnIsPointInRegionf(HSRGN handle, float x, float y) {
     uint32_t sourceRects = rgn->source.Count();
     for (uint32_t i = 0; i < sourceRects; i++) {
         if (!(sourceArray[i].flags & SF_PARAMONLY)) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+            if (x >= sourceArray[i].rect.left && y >= sourceArray[i].rect.top &&
+                x < sourceArray[i].rect.right && y < sourceArray[i].rect.bottom) {
+#else
             if (x >= sourceArray[i].rect.left && y >= sourceArray[i].rect.bottom &&
                 x < sourceArray[i].rect.right && y < sourceArray[i].rect.top) {
+#endif
                 result = 1;
                 break;
             }
diff --git a/storm/region/Types.hpp b/storm/region/Types.hpp
index c7d3766..b0a0454 100644
--- a/storm/region/Types.hpp
+++ b/storm/region/Types.hpp
@@ -8,12 +8,15 @@
 DECLARE_STORM_HANDLE(HSRGN);
 DECLARE_STORM_HANDLE(HLOCKEDRGN);
 
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
 struct RECTF {
-    float left;
-    float bottom;
-    float right;
-    float top;
+    float left, top, right, bottom;
 };
+#else
+struct RECTF {
+    float left, bottom, right, top;
+};
+#endif
 
 #if defined(WHOA_SYSTEM_WIN)
 // NOTE: WINAPI's RECT uses `long`.
diff --git a/test/Region.cpp b/test/Region.cpp
index 83a7ebc..2f03cbc 100644
--- a/test/Region.cpp
+++ b/test/Region.cpp
@@ -498,8 +498,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_OR);
 
         uint32_t numRects = 4;
-        RECT buffer[4];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[4];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         //       ┌────────────┐
         //       |     2      |
@@ -509,9 +509,9 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │    0    │
         // └─────────┘
         CHECK(numRects == 3);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 6, 10, 0 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 10, 18, 6 }));
-        CHECK_THAT(buffer[2], MatchesRecti({ 5, 14, 18, 10 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 6.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 0.0f, 6.0f, 18.0f, 10.0f }));
+        CHECK_THAT(buffer[2], MatchesRectf({ 5.0f, 10.0f, 18.0f, 14.0f }));
     }
 
     SECTION("OR operation on self does nothing") {
@@ -519,11 +519,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_OR);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 10.0f }));
     }
 
     SECTION("OR operation merges vertical rects") {
@@ -534,11 +534,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &rect2, nullptr, SRGN_OR);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 30, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 30.0f }));
     }
 
     SECTION("OR operation merges vertical rects 2") {
@@ -549,11 +549,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_OR);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 30, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 30.0f }));
     }
 
     SECTION("OR operation merges horizontal rects") {
@@ -564,11 +564,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &rect2, nullptr, SRGN_OR);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 30, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 30.0f, 10.0f }));
     }
 
     SECTION("OR operation merges horizontal rects 2") {
@@ -579,11 +579,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_OR);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 30, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 30.0f, 10.0f }));
     }
 
     SECTION("AND operation intersects rects") {
@@ -591,8 +591,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_AND);
 
         uint32_t numRects = 2;
-        RECT buffer[2];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[2];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         //       ┌────────────┐
         //       |╳╳╳╳╳╳╳╳╳╳╳╳|
@@ -602,7 +602,7 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │╳╳╳╳╳╳╳╳╳│
         // └─────────┘
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 5, 10, 10, 6 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 5.0f, 6.0f, 10.0f, 10.0f }));
     }
 
     SECTION("AND operation on self does nothing") {
@@ -610,11 +610,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_AND);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 10.0f }));
     }
 
     SECTION("XOR operation takes exclusive differences of rects") {
@@ -622,8 +622,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_XOR);
 
         uint32_t numRects = 5;
-        RECT buffer[5];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[5];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         //       ┌────────────┐
         //       |      3     |
@@ -633,10 +633,10 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │    0    │
         // └─────────┘
         CHECK(numRects == 4);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 6, 10, 0 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 10, 5, 6 }));
-        CHECK_THAT(buffer[2], MatchesRecti({ 10, 10, 18, 6 }));
-        CHECK_THAT(buffer[3], MatchesRecti({ 5, 14, 18, 10 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 6.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 0.0f, 6.0f, 5.0f, 10.0f }));
+        CHECK_THAT(buffer[2], MatchesRectf({ 10.0f, 6.0f, 18.0f, 10.0f }));
+        CHECK_THAT(buffer[3], MatchesRectf({ 5.0f, 10.0f, 18.0f, 14.0f }));
     }
 
     SECTION("XOR operation on self erases rect") {
@@ -654,8 +654,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_DIFF);
 
         uint32_t numRects = 5;
-        RECT buffer[5];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[5];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         //       ┌────────────┐
         //       |╳╳╳╳╳╳╳╳╳╳╳╳|
@@ -665,8 +665,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │    0    │
         // └─────────┘
         CHECK(numRects == 2);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 6, 10, 0 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 10, 5, 6 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 6.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 0.0f, 6.0f, 5.0f, 10.0f }));
     }
 
     SECTION("DIFF operation on self erases rect") {
@@ -684,8 +684,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_COPY);
 
         uint32_t numRects = 5;
-        RECT buffer[5];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[5];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         //       ┌────────────┐
         //       |╳╳╳╳╳╳╳╳╳╳╳╳|
@@ -695,8 +695,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │    0    │
         // └─────────┘
         CHECK(numRects == 2);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 6, 10, 0 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 10, 10, 6 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 6.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 0.0f, 6.0f, 10.0f, 10.0f }));
     }
 
     SECTION("COPY operation splits intersecting rects 2") {
@@ -705,8 +705,8 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect2, nullptr, SRGN_COPY);
 
         uint32_t numRects = 5;
-        RECT buffer[5];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[5];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         // ┌───────────┐
         // │     2     │
@@ -715,9 +715,9 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         // │     0     │
         // └───────────┘
         CHECK(numRects == 3);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 4, 10, 0 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 6, 10, 4 }));
-        CHECK_THAT(buffer[2], MatchesRecti({ 0, 10, 10, 6 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 4.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 0.0f, 4.0f, 10.0f, 6.0f }));
+        CHECK_THAT(buffer[2], MatchesRectf({ 0.0f, 6.0f, 10.0f, 10.0f }));
     }
 
     SECTION("COPY operation on self does nothing") {
@@ -725,11 +725,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_COPY);
 
         uint32_t numRects = 1;
-        RECT buffer[1];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[1];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 10.0f }));
     }
 
     SECTION("operation doesn't work when operating rect width or height is <= 0") {
@@ -742,15 +742,14 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         );
 
         SRgnCombineRecti(region, &baseRect, nullptr, SRGN_OR);
-
-        uint32_t numRects = 5;
-        RECT buffer[5];
-
         SRgnCombineRecti(region, &testRects, &testRects, combineMode);
 
-        SRgnGetRectsi(region, &numRects, buffer);
+        uint32_t numRects = 5;
+        RECTF buffer[5];
+
+        SRgnGetRectsf(region, &numRects, buffer);
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 10.0f }));
 
         uint32_t numParams = 1;
         SRgnGetRectParamsi(region, &testRects, &numParams, nullptr);
@@ -792,11 +791,11 @@ TEST_CASE("SRgnCombineRecti", "[region]") {
         SRgnCombineRecti(region, &testRect, nullptr, SRGN_PARAMONLY);
 
         uint32_t numRects = 5;
-        RECT buffer[5];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[5];
+        SRgnGetRectsf(region, &numRects, buffer);
 
         CHECK(numRects == 1);
-        CHECK_THAT(buffer[0], MatchesRecti({ 0, 10, 10, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ 0.0f, 0.0f, 10.0f, 10.0f }));
     }
 }
 
@@ -1277,7 +1276,7 @@ TEST_CASE("SRgnGetRectsf", "[region]") {
             { 0, 0, 1, 1 },
             { 4, -2, 5, 5 },
             { -2, 2, -1, 3 },
-            { 2, -2, 3, -1 },
+            { 2, -3, 3, -1 },
         };
 
         for (int i = 0; i < 4; i++) {
@@ -1289,18 +1288,25 @@ TEST_CASE("SRgnGetRectsf", "[region]") {
         SRgnGetRectsf(region, &numrects, buffer);
 
         CHECK(numrects == 4);
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+        CHECK_THAT(buffer[0], MatchesRectf(rects[3]));
+        CHECK_THAT(buffer[1], MatchesRectf(rects[1]));
+        CHECK_THAT(buffer[2], MatchesRectf(rects[0]));
+        CHECK_THAT(buffer[3], MatchesRectf(rects[2]));
+#else
         CHECK_THAT(buffer[0], MatchesRectf(rects[3]));
         CHECK_THAT(buffer[1], MatchesRectf(rects[0]));
         CHECK_THAT(buffer[2], MatchesRectf(rects[2]));
         CHECK_THAT(buffer[3], MatchesRectf(rects[1]));
+#endif
     }
 
     SECTION("retrieves rects in order of left value when tops are equal") {
         RECTF rects[4] = {
             { 0, 0, 1, 1 },
-            { 4, 0.5, 5, 1 },
-            { -2, -2, -1, 1 },
-            { 2, -1, 3, 1 },
+            { 4, 0, 5, 1 },
+            { -2, 0, -1, 1 },
+            { 2, 0, 3, 1 },
         };
 
         for (int i = 0; i < 4; i++) {
@@ -1353,8 +1359,13 @@ TEST_CASE("SRgnGetRectsi", "[region]") {
         REQUIRE(numrects == 2);
         SRgnGetRectsi(region, &numrects, buffer);
 
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+        CHECK_THAT(buffer[0], MatchesRecti({ 0, 0, 1, 1 }));
+        CHECK_THAT(buffer[1], MatchesRecti({ 5, 5, 10, 10 }));
+#else
         CHECK_THAT(buffer[0], MatchesRecti({ 0, 1, 1, 0 }));
         CHECK_THAT(buffer[1], MatchesRecti({ 5, 10, 10, 5 }));
+#endif
     }
 
     SECTION("automatically merges overlapping rects") {
@@ -1370,7 +1381,11 @@ TEST_CASE("SRgnGetRectsi", "[region]") {
         REQUIRE(numrects == 1);
         SRgnGetRectsi(region, &numrects, buffer);
 
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+        CHECK_THAT(buffer[0], MatchesRecti({ -10, -10, 10, 10 }));
+#else
         CHECK_THAT(buffer[0], MatchesRecti({ -10, 10, 10, -10 }));
+#endif
     }
 
     SECTION("retrieves rects in order of top value") {
@@ -1378,7 +1393,7 @@ TEST_CASE("SRgnGetRectsi", "[region]") {
             { 0.0f, 0.0f, 1.0f, 1.0f },
             { 4.0f, -2.0f, 5.0f, 5.0f },
             { -2.0f, 2.0f, -1.0f, 3.0f },
-            { 2.0f, -2.0f, 3.0f, -1.0f },
+            { 2.0f, -3.0f, 3.0f, -1.0f },
         };
 
         for (int i = 0; i < 4; i++) {
@@ -1390,18 +1405,25 @@ TEST_CASE("SRgnGetRectsi", "[region]") {
         SRgnGetRectsi(region, &numrects, buffer);
 
         CHECK(numrects == 4);
-        CHECK_THAT(buffer[0], MatchesRecti({ 2, -1, 3, -2 }));
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+        CHECK_THAT(buffer[0], MatchesRecti({ 2, -3, 3, -1 }));
+        CHECK_THAT(buffer[1], MatchesRecti({ 4, -2, 5, 5 }));
+        CHECK_THAT(buffer[2], MatchesRecti({ 0, 0, 1, 1 }));
+        CHECK_THAT(buffer[3], MatchesRecti({ -2, 2, -1, 3 }));
+#else
+        CHECK_THAT(buffer[0], MatchesRecti({ 2, -1, 3, -3 }));
         CHECK_THAT(buffer[1], MatchesRecti({ 0, 1, 1, 0 }));
         CHECK_THAT(buffer[2], MatchesRecti({ -2, 3, -1, 2 }));
         CHECK_THAT(buffer[3], MatchesRecti({ 4, 5, 5, -2 }));
+#endif
     }
 
     SECTION("retrieves rects in order of left value when tops are equal") {
         RECTF rects[4] = {
             { 0, 0, 10, 10 },
-            { 40, 5, 50, 10 },
-            { -20, -20, -10, 10 },
-            { 20, -10, 30, 10 },
+            { 40, 0, 50, 10 },
+            { -20, 0, -10, 10 },
+            { 20, 0, 30, 10 },
         };
 
         for (int i = 0; i < 4; i++) {
@@ -1413,10 +1435,17 @@ TEST_CASE("SRgnGetRectsi", "[region]") {
         SRgnGetRectsi(region, &numrects, buffer);
 
         CHECK(numrects == 4);
-        CHECK_THAT(buffer[0], MatchesRecti({ -20, 10, -10, -20 }));
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+        CHECK_THAT(buffer[0], MatchesRecti({ -20, 0, -10, 10 }));
+        CHECK_THAT(buffer[1], MatchesRecti({ 0, 0, 10, 10 }));
+        CHECK_THAT(buffer[2], MatchesRecti({ 20, 0, 30, 10 }));
+        CHECK_THAT(buffer[3], MatchesRecti({ 40, 0, 50, 10 }));
+#else
+        CHECK_THAT(buffer[0], MatchesRecti({ -20, 10, -10, 0 }));
         CHECK_THAT(buffer[1], MatchesRecti({ 0, 10, 10, 0 }));
-        CHECK_THAT(buffer[2], MatchesRecti({ 20, 10, 30, -10 }));
-        CHECK_THAT(buffer[3], MatchesRecti({ 40, 10, 50, 5 }));
+        CHECK_THAT(buffer[2], MatchesRecti({ 20, 10, 30, 0 }));
+        CHECK_THAT(buffer[3], MatchesRecti({ 40, 10, 50, 0 }));
+#endif
     }
 }
 
@@ -1775,11 +1804,11 @@ TEST_CASE("SRgnOffseti", "[region]") {
         SRgnOffseti(region, 1000, 500);
 
         uint32_t numRects = 2;
-        RECT buffer[2];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[2];
+        SRgnGetRectsf(region, &numRects, buffer);
 
-        CHECK_THAT(buffer[0], MatchesRecti({ -1000, -500, 0, -1500 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 1000, 1500, 2000, 500 }));
+        CHECK_THAT(buffer[0], MatchesRectf({ -1000.0f, -1500.0f, 0.0f, -500.0f }));
+        CHECK_THAT(buffer[1], MatchesRectf({ 1000.0f, 500.0f, 2000.0f, 1500.0f }));
     }
 
     SECTION("shifts rects back to their original positions with opposite amounts") {
@@ -1796,11 +1825,11 @@ TEST_CASE("SRgnOffseti", "[region]") {
         SRgnOffseti(region, -1050, -600);
 
         uint32_t numRects = 2;
-        RECT buffer[2];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[2];
+        SRgnGetRectsf(region, &numRects, buffer);
 
-        CHECK_THAT(buffer[0], MatchesRecti({ -2000, -1000, -1000, -2000 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 1000, 1000, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf(rects[0]));
+        CHECK_THAT(buffer[1], MatchesRectf(rects[1]));
     }
 
     SECTION("doesn't shift anything with 0") {
@@ -1815,10 +1844,10 @@ TEST_CASE("SRgnOffseti", "[region]") {
         SRgnOffseti(region, 0, 0);
 
         uint32_t numRects = 2;
-        RECT buffer[2];
-        SRgnGetRectsi(region, &numRects, buffer);
+        RECTF buffer[2];
+        SRgnGetRectsf(region, &numRects, buffer);
 
-        CHECK_THAT(buffer[0], MatchesRecti({ -2000, -1000, -1000, -2000 }));
-        CHECK_THAT(buffer[1], MatchesRecti({ 0, 1000, 1000, 0 }));
+        CHECK_THAT(buffer[0], MatchesRectf(rects[0]));
+        CHECK_THAT(buffer[1], MatchesRectf(rects[1]));
     }
 }
diff --git a/test/RegionTest.hpp b/test/RegionTest.hpp
index f7f2b8a..c424177 100644
--- a/test/RegionTest.hpp
+++ b/test/RegionTest.hpp
@@ -22,7 +22,11 @@ struct RgnDataTest {
 
 // Helpers for comparing RECTF structs
 std::ostream& operator <<(std::ostream& os, RECTF const& value) {
+#if defined(WHOA_RECT_USES_SCREEN_COORDINATES)
+    os << "{ " << value.left << ", " << value.top << ", " << value.right << ", " << value.bottom << " }";
+#else
     os << "{ " << value.left << ", " << value.bottom << ", " << value.right << ", " << value.top << " }";
+#endif
     return os;
 }