From 47efa26cfc058d87e532f18373008e7eb6c7a02a Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Thu, 16 Jul 2020 14:52:51 +0200
Subject: [PATCH] gpu: limit atlas textures to 8k x 8k

Fixes gio#131
Fixes gio#133

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 gpu/gpu.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/gpu/gpu.go b/gpu/gpu.go
index 5c80d087..c7a418c4 100644
--- a/gpu/gpu.go
+++ b/gpu/gpu.go
@@ -409,8 +409,16 @@ func newRenderer(ctx backend.Device) *renderer {
 		blitter: newBlitter(ctx),
 		pather:  newPather(ctx),
 	}
-	r.packer.maxDim = ctx.Caps().MaxTextureSize
-	r.intersections.maxDim = r.packer.maxDim
+
+	maxDim := ctx.Caps().MaxTextureSize
+	// Large atlas textures cause artifacts due to precision loss in
+	// shaders.
+	if cap := 8192; maxDim > cap {
+		maxDim = cap
+	}
+
+	r.packer.maxDim = maxDim
+	r.intersections.maxDim = maxDim
 	return r
 }