From 3a51ce98433807f89473fa5dc822aefa574a3a99 Mon Sep 17 00:00:00 2001
From: Thomas Friedel <tomee6@gmail.com>
Date: Mon, 30 Apr 2018 11:25:25 +0200
Subject: [PATCH] more clipping fixes

---
 images.go | 4 ++++
 text.go   | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/images.go b/images.go
index 837b510..620490e 100644
--- a/images.go
+++ b/images.go
@@ -249,6 +249,8 @@ func (cv *Canvas) DrawImage(image interface{}, coords ...float64) {
 	p2 := cv.tf(vec{dx + dw, dy + dh})
 	p3 := cv.tf(vec{dx + dw, dy})
 
+	gli.StencilFunc(gl_EQUAL, 0, 0xFF)
+
 	gli.BindBuffer(gl_ARRAY_BUFFER, buf)
 	data := [16]float32{float32(p0[0]), float32(p0[1]), float32(p1[0]), float32(p1[1]), float32(p2[0]), float32(p2[1]), float32(p3[0]), float32(p3[1]),
 		float32(sx), float32(sy), float32(sx), float32(sy + sh), float32(sx + sw), float32(sy + sh), float32(sx + sw), float32(sy)}
@@ -268,4 +270,6 @@ func (cv *Canvas) DrawImage(image interface{}, coords ...float64) {
 	gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
 	gli.DisableVertexAttribArray(ir.vertex)
 	gli.DisableVertexAttribArray(ir.texCoord)
+
+	gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
 }
diff --git a/text.go b/text.go
index f17d682..d34dae1 100644
--- a/text.go
+++ b/text.go
@@ -181,6 +181,8 @@ func (cv *Canvas) FillText(str string, x, y float64) {
 		x -= float64(strWidth)
 	}
 
+	gli.StencilFunc(gl_EQUAL, 0, 0xFF)
+
 	gli.BindBuffer(gl_ARRAY_BUFFER, buf)
 
 	vertex, alphaTexCoord := cv.useAlphaShader(&cv.state.fill, 1)
@@ -219,6 +221,8 @@ func (cv *Canvas) FillText(str string, x, y float64) {
 	gli.DisableVertexAttribArray(alphaTexCoord)
 
 	gli.ActiveTexture(gl_TEXTURE0)
+
+	gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
 }
 
 type TextMetrics struct {