config: start implementing json-based configuration files

src/JsonCoordinateMapping.cpp

@@ -0,0 +1,70 @@
+#include "./JsonCoordinateMapping.h"
+
+unsigned int
+JsonCoordinateMapping::physicalPixelCount() const {
+  int total = 0;
+  for(int i = 0; i < strideCount; i++) {
+    total += displayMap[i].length;
+  }
+  return total;
+}
+
+int
+JsonCoordinateMapping::physicalCoordsToIndex(const PhysicalCoordinates localCoords) const {
+  uint8_t idx = 0;
+  bool inverse = false;
+  for(int i = 0; i < localCoords.x; i++) { 
+    idx += displayMap[i].length;
+    inverse = !inverse;
+  }
+  if (inverse) {
+    idx += std::max(0, displayMap[localCoords.x].length - 1 - std::max(0, (int)localCoords.y - displayMap[localCoords.x].y));
+  } else {
+    idx += std::min((int)displayMap[localCoords.x].length - 1, std::max(0, (int)localCoords.y - displayMap[localCoords.x].y));
+  }
+  return idx;
+}
+
+PhysicalCoordinates
+JsonCoordinateMapping::virtualToPhysicalCoords(const VirtualCoordinates virtualCoords) const {
+  const uint8_t spanIdx = scale8(strideCount-1, virtualCoords.x);
+  const uint8_t spanOffset = scale8(maxStrideSize - 1, virtualCoords.y);
+  return PhysicalCoordinates{spanIdx, spanOffset};
+}
+
+VirtualCoordinates 
+JsonCoordinateMapping::physicalToVirtualCoords(const PhysicalCoordinates localCoords) const {
+  int offset = localCoords.x;
+  for(int i = 0; i < strideCount; i++) {
+    if (offset > displayMap[i].length) {
+      offset -= displayMap[i].length;
+    } else {
+      return VirtualCoordinates{i, offset};
+    }
+  }
+  return VirtualCoordinates{0, 0};
+}
+
+void
+JsonCoordinateMapping::load(const JsonArray& strideList)
+{
+  maxStrideSize = 0;
+  strideCount = strideList.size();
+  for(int i = 0; i < strideList.size();i++) {
+    JsonObject strideObj = strideList[i];
+    int length = strideObj["pixels"];
+    int x = strideObj["x"];
+    int y = strideObj["y"];
+    displayMap[i] = Span{length, x, y};
+    Log.verbose("config: Found stride (%d, %d): %d", x, y, length);
+    maxStrideSize = length > maxStrideSize ? length : maxStrideSize;
+  }
+}
+
+void
+JsonCoordinateMapping::loadDefault()
+{
+    displayMap[0] = Span{255, 0, 0};
+    maxStrideSize = 255;
+    strideCount = 1;
+}

src/JsonCoordinateMapping.h

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+#pragma once
+#include <Figments.h>
+#include <ArduinoJson.h>
+
+struct JsonCoordinateMapping : CoordinateMapping {
+  struct Span {
+    int length = 0;
+    int x = 0;
+    int y = 0;
+
+    Span() {}
+    Span(int length, int x, int y) : length(length), x(x), y(y) {}
+  };
+
+  Span displayMap[32];
+  int strideCount = 0;
+  int maxStrideSize = 0;
+
+  void load(const JsonArray& strides);
+  void loadDefault();
+
+  VirtualCoordinates physicalToVirtualCoords(const PhysicalCoordinates localCoords) const override;
+  PhysicalCoordinates virtualToPhysicalCoords(const VirtualCoordinates virtualCoords) const override;
+  int physicalCoordsToIndex(const PhysicalCoordinates localCoords) const override;
+  unsigned int physicalPixelCount() const override;
+};