Speeding up adjustcolor alpha

R/color-paletts.R

@@ -102,6 +102,17 @@ colorRamp2 <- function(x, alpha = TRUE, thresholds=NULL) {
 
 }
 
+alphacolor <- function(col, alpha.f) {
+  val <- strtoi(substring(col, 8L), base = 16L)
+  substring(col, 8) <- sprintf("%02X", floor(val * alpha.f))
+  return(col)
+}
+
+# microbenchmark::microbenchmark(
+#   alphacolor("#0000FF80", .5),
+#   adjustcolor("#0000FF80", .5), times = 1e3, check = "identical"
+# )
+
 #' Draw segments colored by gradients
 #' @param x,y Coordinates passed to [grDevices::xy.coords].
 #' @param col Color ramp function (see [grDevices::colorRamp]).

R/coloring.R

@@ -31,8 +31,8 @@ new_edge_coloring <- function(
       # Applying alpha levels and getting mix
       col <- colorRamp2(
         x = c(
-          grDevices::adjustcolor(col = col_i, alpha.f = alpha_i),
-          grDevices::adjustcolor(col = col_j, alpha.f = alpha_j)
+          alphacolor(col = col_i, alpha.f = alpha_i),
+          alphacolor(col = col_j, alpha.f = alpha_j)
         )
       )(seq(0, 1, length.out = n))
 
@@ -47,13 +47,13 @@ new_edge_coloring <- function(
       alpha_j <- vertex_alpha_j[j]
 
       # Edge level params
-      col_ij   <- grDevices::adjustcolor(col = edge_color[e], alpha.f = edge_alpha[e])
+      col_ij   <- alphacolor(col = edge_color[e], alpha.f = edge_alpha[e])
 
       # Applying alpha levels and getting mix
       col <- colorRamp2(x=
         c(
-          grDevices::adjustcolor(col = col_ij, alpha.f = alpha_i),
-          grDevices::adjustcolor(col = col_ij, alpha.f = alpha_j)
+          alphacolor(col = col_ij, alpha.f = alpha_i),
+          alphacolor(col = col_ij, alpha.f = alpha_j)
         )
       )(seq(0, 1, length.out = n))
 

R/netplot.R

@@ -7,10 +7,14 @@
 #' @noRd
 edge_color_mixer <- function(i, j, vcols, p = .5, alpha = .15) {
 
-  grDevices::adjustcolor(grDevices::rgb(
-    colorRamp2(vcols[c(i,j)], alpha = FALSE)(p),
-    maxColorValue = 255
-  ), alpha = alpha)
+  alphacolor(
+    sprintf(
+      "%sFF", grDevices::rgb(
+        colorRamp2(vcols[c(i,j)], alpha = FALSE)(p),
+        maxColorValue = 255
+        )
+      ), alpha.f = alpha
+    )
 
 }