move packLineStyleMetadata into helper

Author: stmitt

ios/graphics/Shader/Metal/LineShader.metal

@@ -27,24 +27,24 @@ struct LineVertexIn {
     float2 lineA [[attribute(0)]];
     float2 lineB [[attribute(1)]];
   /*
-      lineStyleInfo is packed as a single float but contains multiple pieces of information:
+      lineMetadata is packed as a single float but contains multiple pieces of information:
       - Bits  0-1  : Vertex Index (0-3) (used for rendering different parts of the quad)
       - Bits  2-9  : Line Style Index (0-255) (defines the appearance of the line)
       - Bits 10-11 : Segment Type (0 = inner, 1 = start, 2 = end, 3 = single-segment)
     */
-   float lineStyleInfo [[attribute(2)]];
+   float lineMetadata [[attribute(2)]];
 };
 
 struct LineVertexUnitSphereIn {
     float3 lineA [[attribute(0)]];
     float3 lineB [[attribute(1)]];
   /*
-      lineStyleInfo is packed as a single float but contains multiple pieces of information:
+      lineMetadata is packed as a single float but contains multiple pieces of information:
       - Bits  0-1  : Vertex Index (0-3) (used for rendering different parts of the quad)
       - Bits  2-9  : Line Style Index (0-255) (defines the appearance of the line)
       - Bits 10-11 : Segment Type (0 = inner, 1 = start, 2 = end, 3 = single-segment)
     */
-   float lineStyleInfo [[attribute(2)]];
+   float lineMetadata [[attribute(2)]];
 };
 
 struct LineVertexOut {
@@ -115,7 +115,7 @@ unitSphereSimpleLineGroupVertexShader(const LineVertexUnitSphereIn vertexIn [[st
                       constant float4 &originOffset [[buffer(5)]],
                       constant float4 &tileOrigin [[buffer(6)]])
 {
-    const uint packed = as_type<uint>(vertexIn.lineStyleInfo); // Reinterpret float as uint
+    const uint packed = as_type<uint>(vertexIn.lineMetadata); // Reinterpret float as uint
     const uint vertexIndex = packed & 0x3;                  // Bits 0-1
     const uint styleIndex = (packed >> 2) & 0xFF;       // Bits 2-9
     const uint segmentType = (packed >> 10) & 0x3;          // Bits 10-11
@@ -184,7 +184,7 @@ simpleLineGroupVertexShader(const LineVertexIn vertexIn [[stage_in]],
                       constant float4 &originOffset [[buffer(5)]],
                       constant float4 &tileOrigin [[buffer(6)]])
 {
-    const uint packed = as_type<uint>(vertexIn.lineStyleInfo); // Reinterpret float as uint
+    const uint packed = as_type<uint>(vertexIn.lineMetadata); // Reinterpret float as uint
     const uint vertexIndex = packed & 0x3;                  // Bits 0-1
     const uint styleIndex = (packed >> 2) & 0xFF;       // Bits 2-9
     const uint segmentType = (packed >> 10) & 0x3;          // Bits 10-11
@@ -304,7 +304,7 @@ unitSphereLineGroupVertexShader(const LineVertexUnitSphereIn vertexIn [[stage_in
                       constant float4 &tileOrigin [[buffer(6)]])
 {
 
-    const uint packed = as_type<uint>(vertexIn.lineStyleInfo); // Reinterpret float as uint
+    const uint packed = as_type<uint>(vertexIn.lineMetadata); // Reinterpret float as uint
     const uint vertexIndex = packed & 0x3;                  // Bits 0-1
     const uint styleIndex = (packed >> 2) & 0xFF;       // Bits 2-9
     const uint segmentType = (packed >> 10) & 0x3;          // Bits 10-11
@@ -384,7 +384,7 @@ lineGroupVertexShader(const LineVertexIn vertexIn [[stage_in]],
                       constant float4 &originOffset [[buffer(5)]],
                       constant float4 &tileOrigin [[buffer(6)]])
 {
-    const uint packed = as_type<uint>(vertexIn.lineStyleInfo); // Reinterpret float as uint
+    const uint packed = as_type<uint>(vertexIn.lineMetadata); // Reinterpret float as uint
     const uint vertexIndex = packed & 0x3;                  // Bits 0-1
     const uint styleIndex = (packed >> 2) & 0xFF;       // Bits 2-9
     const uint segmentType = (packed >> 10) & 0x3;          // Bits 10-11

shared/public/LineHelper.h

@@ -72,7 +72,17 @@ class LineHelper {
         return newPolyline;
     }
 
-
+    inline static float packLineStyleMetadata(uint8_t vertexIndex, uint8_t lineStyleIndex, uint8_t segmentType, float prefixTotalLineLength) {
+        uint32_t packed =
+              (vertexIndex & 0x3)
+            | ((lineStyleIndex & 0xFF) << 2)
+            | ((segmentType & 0x3) << 10)
+            | ((int(prefixTotalLineLength * 1000.0) & 0x1FFFFF) << 11);
+
+        float result;
+        std::memcpy(&result, &packed, sizeof(float));  // Preserve all 32 bits
+        return result;
+    }
 
 private:
     static float distanceSquared(const Coord& pt, const Coord &p1, const Coord &p2)

shared/src/map/layers/objects/Line2dLayerObject.cpp

@@ -10,6 +10,7 @@
 
 #include "Line2dLayerObject.h"
 #include "Vec3D.h"
+#include "LineHelper.h"
 #include <cmath>
 
 Line2dLayerObject::Line2dLayerObject(const std::shared_ptr<CoordinateConversionHelperInterface> &conversionHelper,
@@ -63,12 +64,6 @@ void Line2dLayerObject::setPositions(const std::vector<Coord> &positions, const
         uint8_t segmentType = (i == 0 && i == iSecondToLast) ? 3 :
                               (i == 0) ? 1 :
                               (i == iSecondToLast) ? 2 : 0;
-        const int lineStyleIndex = 0;
-        float lineStyleInfo = static_cast<float>(
-            (segmentType << 10) | // 2 bits for segmentType (shifted left)
-            (lineStyleIndex << 2) | // 8 bits for lineStyleIndex
-            0 // Reserve 2 bits for vertexIndex
-        );
 
         for (uint8_t vertexIndex = 4; vertexIndex > 0; --vertexIndex) {
             // Vertex
@@ -84,12 +79,7 @@ void Line2dLayerObject::setPositions(const std::vector<Coord> &positions, const
                 lineAttributes.push_back(pNext.z);
             }
 
-            // Segment Start Length Position (length prefix sum)
-            lineAttributes.push_back(prefixTotalLineLength);
-
-            // Vertex Index (store in last 2 bits)
-            float packedStyleInfo = lineStyleInfo + (vertexIndex - 1);
-            lineAttributes.push_back(packedStyleInfo);
+            lineAttributes.push_back(LineHelper::packLineStyleMetadata(vertexIndex, 0, segmentType, prefixTotalLineLength));
         }
 
         // Vertex indices

shared/src/map/layers/objects/LineGroup2dLayerObject.cpp

@@ -12,7 +12,7 @@
 #include "RenderLineDescription.h"
 #include "Logger.h"
 #include "ShaderLineStyle.h"
-
+#include "LineHelper.h"
 #include <cmath>
 
 LineGroup2dLayerObject::LineGroup2dLayerObject(const std::shared_ptr<CoordinateConversionHelperInterface> &conversionHelper,
@@ -29,18 +29,6 @@ void LineGroup2dLayerObject::update() {}
 
 std::vector<std::shared_ptr<RenderConfigInterface>> LineGroup2dLayerObject::getRenderConfig() { return {renderConfig}; }
 
-float packLineStyleMetadata(uint8_t vertexIndex, uint8_t lineStyleIndex, uint8_t segmentType, float prefixTotalLineLength) {
-    uint32_t packed =
-          (vertexIndex & 0x3)
-        | ((lineStyleIndex & 0xFF) << 2)
-        | ((segmentType & 0x3) << 10)
-        | ((int(prefixTotalLineLength * 1000.0) & 0x1FFFFF) << 11);
-
-    float result;
-    std::memcpy(&result, &packed, sizeof(float));  // Preserve all 32 bits
-    return result;
-}
-
 void LineGroup2dLayerObject::setLines(const std::vector<std::tuple<std::vector<Coord>, int>> &lines, const Vec3D & origin) {
 
     std::vector<uint32_t> lineIndices;
@@ -95,8 +83,7 @@ void LineGroup2dLayerObject::setLines(const std::vector<std::tuple<std::vector<C
                     lineAttributes.push_back(pNext.z);
                 }
 
-                float lineStyleMetadata = packLineStyleMetadata(vertexIndex, lineStyleIndex, segmentType, prefixTotalLineLength);
-                lineAttributes.push_back(lineStyleMetadata);
+                lineAttributes.push_back(LineHelper::packLineStyleMetadata(vertexIndex, lineStyleIndex, segmentType, prefixTotalLineLength));
             }
 
             // Vertex indices