From d6cc00dcce1a723d9c4f0ad81f4ae4c4b36370fe Mon Sep 17 00:00:00 2001
From: James Legg <lankyleggy@gmail.com>
Date: Sun, 13 Mar 2016 17:32:34 +0000
Subject: [PATCH] arb_tessellation_shader: Check single isolines can be created

From the spec:
"The number of isolines generated is derived from the first outer
tessellation level; the number of segments in each isoline is derived from
the second outer tessellation level."

This demonstrates a bug on Intel Haswell, where the number of isolines is
derived from the second outer tessellation level, and the number of
segments from the first.
---
 .../execution/isoline.shader_test                  | 52 ++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 tests/spec/arb_tessellation_shader/execution/isoline.shader_test

diff --git a/tests/spec/arb_tessellation_shader/execution/isoline.shader_test b/tests/spec/arb_tessellation_shader/execution/isoline.shader_test
new file mode 100644
index 0000000..ef2fd9c
--- /dev/null
+++ b/tests/spec/arb_tessellation_shader/execution/isoline.shader_test
@@ -0,0 +1,52 @@
+# Check producing a single tessellated isoline doesn't give multiple lines
+[require]
+GLSL >= 1.50
+GL_ARB_tessellation_shader
+
+[vertex shader]
+
+void main()
+{
+}
+
+
+[tessellation control shader]
+#extension GL_ARB_tessellation_shader: require
+layout(vertices = 2) out;
+
+void main()
+{
+	gl_TessLevelOuter[0] = 1.0;
+	gl_TessLevelOuter[1] = 4.0;
+}
+
+
+[tessellation evaluation shader]
+#extension GL_ARB_tessellation_shader: require
+layout(isolines, equal_spacing) in;
+flat out int good;
+
+void main()
+{
+	gl_Position = vec4(gl_TessCoord.xy * 2.0 - 1.0, 0.0, 1.0);
+	good = int(gl_TessCoord.y == 0.0);
+}
+
+
+[fragment shader]
+flat in int good;
+
+void main()
+{
+	if (bool(good))
+		gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
+	else
+		gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+}
+
+[test]
+clear color 0.0 1.0 0.0 1.0
+clear
+patch parameter vertices 2
+draw arrays GL_PATCHES 0 2
+probe all rgba 0.0 1.0 0.0 1.0
-- 
2.5.0