[libcamera-devel] [PATCH 04/12] ipa: ipu3: awb: Make the naming consistent

[Jean-Michel Hautbois]

The variables mix the terms cell, region and zone. It can confuse the
reader, and make the algorithm more difficult to follow. Rename the
local variables consistent with their definitions:
- Cells are defined in Pixels
- Zones are defined in Cells
There is no "region" as such, so replace it with the correct term.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
---
 src/ipa/ipu3/algorithms/awb.cpp | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
index d78ae4f4..51a38d05 100644
--- a/src/ipa/ipu3/algorithms/awb.cpp
+++ b/src/ipa/ipu3/algorithms/awb.cpp
@@ -220,31 +220,34 @@ void Awb::generateZones(std::vector<RGB> &zones)
 void Awb::generateAwbStats(const ipu3_uapi_stats_3a *stats,
 			   const ipu3_uapi_grid_config &grid)
 {
-	uint32_t regionWidth = round(grid.width / static_cast<double>(kAwbStatsSizeX));
-	uint32_t regionHeight = round(grid.height / static_cast<double>(kAwbStatsSizeY));
+	uint32_t cellsPerZoneX = round(grid.width / static_cast<double>(kAwbStatsSizeX));
+	uint32_t cellsPerZoneY = round(grid.height / static_cast<double>(kAwbStatsSizeY));
 
 	/*
 	 * Generate a (kAwbStatsSizeX x kAwbStatsSizeY) array from the IPU3 grid which is
 	 * (grid.width x grid.height).
 	 */
-	for (unsigned int j = 0; j < kAwbStatsSizeY * regionHeight; j++) {
-		for (unsigned int i = 0; i < kAwbStatsSizeX * regionWidth; i++) {
-			uint32_t cellPosition = j * grid.width + i;
-			uint32_t cellX = (cellPosition / regionWidth) % kAwbStatsSizeX;
-			uint32_t cellY = ((cellPosition / grid.width) / regionHeight) % kAwbStatsSizeY;
+	for (unsigned int cellY = 0; cellY < kAwbStatsSizeY * cellsPerZoneY; cellY++) {
+		for (unsigned int cellX = 0; cellX < kAwbStatsSizeX * cellsPerZoneX; cellX++) {
+			uint32_t cellPosition = (cellY * grid.width + cellX)
+					      * sizeof(Ipu3AwbCell);
+			uint32_t zoneX = cellX / cellsPerZoneX;
+			uint32_t zoneY = cellY / cellsPerZoneY;
 
-			uint32_t awbRegionPosition = cellY * kAwbStatsSizeX + cellX;
-			cellPosition *= 8;
+			uint32_t awbZonePosition = zoneY * kAwbStatsSizeX + zoneX;
 
 			/* Cast the initial IPU3 structure to simplify the reading */
-			Ipu3AwbCell *currentCell = reinterpret_cast<Ipu3AwbCell *>(const_cast<uint8_t *>(&stats->awb_raw_buffer.meta_data[cellPosition]));
+			const Ipu3AwbCell *currentCell =
+				reinterpret_cast<const Ipu3AwbCell *>(
+					&stats->awb_raw_buffer.meta_data[cellPosition]
+				);
 			if (currentCell->satRatio == 0) {
 				/* The cell is not saturated, use the current cell */
-				awbStats_[awbRegionPosition].counted++;
+				awbStats_[awbZonePosition].counted++;
 				uint32_t greenValue = currentCell->greenRedAvg + currentCell->greenBlueAvg;
-				awbStats_[awbRegionPosition].sum.green += greenValue / 2;
-				awbStats_[awbRegionPosition].sum.red += currentCell->redAvg;
-				awbStats_[awbRegionPosition].sum.blue += currentCell->blueAvg;
+				awbStats_[awbZonePosition].sum.green += greenValue / 2;
+				awbStats_[awbZonePosition].sum.red += currentCell->redAvg;
+				awbStats_[awbZonePosition].sum.blue += currentCell->blueAvg;
 			}
 		}
 	}
-- 
2.30.2