Apply performance improve proposed in ra1nty/DXcam#62

Fidelxyz · Nov 8, 2023 · 9e9a953 · 9e9a953
1 parent 1988fa4
commit 9e9a953
Showing 1 changed file with 39 additions and 11 deletions.
diff --git a/src/core/Processor.cpp b/src/core/Processor.cpp
@@ -6,20 +6,46 @@
 
 namespace DXCam {
 
-cv::Mat Processor::process(const DXGI_MAPPED_RECT &rect, const int width,
-                           const int height, const Region &region,
-                           const int rotation_angle) {
-    const auto pitch = rect.Pitch / 4;
+cv::Mat Processor::process(const DXGI_MAPPED_RECT &rect, int width, int height,
+                           const Region &region, const int rotation_angle) {
+    auto pitch = rect.Pitch;
 
+    // Pre-crop
+    int offset = 0;
+    switch (rotation_angle) {
+        case 0:
+            offset = region.top * pitch;
+            height = region.bottom - region.top;
+            break;
+        case 90:
+            offset = (width - region.right) * pitch;
+            width = region.right - region.left;
+            break;
+        case 180:
+            offset = (height - region.bottom) * pitch;
+            height = region.bottom - region.top;
+            break;
+        case 270:
+            offset = region.left * pitch;
+            width = region.right - region.left;
+            break;
+        default:
+            assert(false);  // never reach
+            break;
+    }
+
+    pitch /= 4;  // number of channels
     cv::Mat image;
     if (rotation_angle == 0 || rotation_angle == 180) {
-        image = cv::Mat(height, pitch, CV_8UC4, rect.pBits);
+        image = cv::Mat(height, pitch, CV_8UC4, rect.pBits + offset);
     } else {
-        image = cv::Mat(width, pitch, CV_8UC4, rect.pBits);
+        image = cv::Mat(width, pitch, CV_8UC4, rect.pBits + offset);
     }
 
-    // TODO untested
+    // Rotation
     switch (rotation_angle) {
+        case 0:
+            break;
         case 90:
             cv::rotate(image, image, cv::ROTATE_90_CLOCKWISE);
             break;
@@ -30,13 +56,15 @@ cv::Mat Processor::process(const DXGI_MAPPED_RECT &rect, const int width,
             cv::rotate(image, image, cv::ROTATE_90_COUNTERCLOCKWISE);
             break;
         default:
+            assert(false);  // never reach
             break;
     }
 
-    if (region.right - region.left != width ||
-        region.bottom - region.top != height) {
-        image = image(cv::Range(region.top, region.bottom),
-                      cv::Range(region.left, region.right));
+    // Crop
+    if (region.right - region.left != width) {
+        image = image.colRange(region.left, region.right);
+    } else if (region.bottom - region.top != height) {
+        image = image.rowRange(region.top, region.bottom);
     }
 
     return image;