From f5d84f0b7b55dd4afe41555916a92f11f0fc9fa8 Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Sun, 26 Oct 2014 22:36:57 +0100
Subject: [PATCH] Only use the transparent image generation if there where any
 transparent blocks.

---
 common/renderer.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/common/renderer.go b/common/renderer.go
index af8f64f..3ca50a3 100644
--- a/common/renderer.go
+++ b/common/renderer.go
@@ -166,7 +166,8 @@ func (r *Renderer) Reset() {
 		r.yMin[i] = math.MinInt32
 	}
 
-	if r.tBuffer != nil {
+	if r.TransparentBlocks > 0 {
+		r.TransparentBlocks = 0
 		for i, t := range r.tBuffer {
 			if t != nil {
 				r.spans.FreeAll(t)
@@ -174,6 +175,8 @@ func (r *Renderer) Reset() {
 			}
 		}
 	}
+	r.SolidBlocks = 0
+	r.RejectedBlocks = 0
 }
 
 func (r *Renderer) IsFilled() bool {
@@ -416,7 +419,7 @@ func (r *Renderer) CreateShadedImage(
 
 	pix := image.Pix
 
-	if r.tBuffer != nil { // Fast path for transparent images.
+	if r.TransparentBlocks > 0 { // Fast path for transparent images.
 		for z := height - 1; z >= 0; z-- {
 			for x := 0; x < width; x++ {
 				colIdx := r.cBuffer[ofs]