Fix some nits in DrawGouraud()
- Mark some references as const-ref.
- Consolidate repeated calculations.
Change-Id: I459f3602dce352deaf9d61e667967ce0446a98cd
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/117710
Reviewed-by: Thomas Sepez <tsepez@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/render/cpdf_rendershading.cpp b/core/fpdfapi/render/cpdf_rendershading.cpp
index d10409a..f4aa82d 100644
--- a/core/fpdfapi/render/cpdf_rendershading.cpp
+++ b/core/fpdfapi/render/cpdf_rendershading.cpp
@@ -359,10 +359,10 @@
float g[3];
float b[3];
for (int i = 0; i < 3; i++) {
- CPDF_MeshVertex& vertex1 = triangle[i];
- CPDF_MeshVertex& vertex2 = triangle[(i + 1) % 3];
- CFX_PointF& position1 = vertex1.position;
- CFX_PointF& position2 = vertex2.position;
+ const CPDF_MeshVertex& vertex1 = triangle[i];
+ const CPDF_MeshVertex& vertex2 = triangle[(i + 1) % 3];
+ const CFX_PointF& position1 = vertex1.position;
+ const CFX_PointF& position2 = vertex2.position;
bool bIntersect =
GetScanlineIntersect(y, position1, position2, &inter_x[nIntersects]);
if (!bIntersect)
@@ -395,12 +395,14 @@
int start_x = std::clamp(min_x, 0, pBitmap->GetWidth());
int end_x = std::clamp(max_x, 0, pBitmap->GetWidth());
- float r_unit = (r[end_index] - r[start_index]) / (max_x - min_x);
- float g_unit = (g[end_index] - g[start_index]) / (max_x - min_x);
- float b_unit = (b[end_index] - b[start_index]) / (max_x - min_x);
- float r_result = r[start_index] + (start_x - min_x) * r_unit;
- float g_result = g[start_index] + (start_x - min_x) * g_unit;
- float b_result = b[start_index] + (start_x - min_x) * b_unit;
+ const int range_x = max_x - min_x;
+ float r_unit = (r[end_index] - r[start_index]) / range_x;
+ float g_unit = (g[end_index] - g[start_index]) / range_x;
+ float b_unit = (b[end_index] - b[start_index]) / range_x;
+ const int diff_x = start_x - min_x;
+ float r_result = r[start_index] + diff_x * r_unit;
+ float g_result = g[start_index] + diff_x * g_unit;
+ float b_result = b[start_index] + diff_x * b_unit;
pdfium::span<uint8_t> dib_span =
pBitmap->GetWritableScanline(y).subspan(start_x * 4);
