From bfbe415ea82ec20c870bf1db60920b7bd12387a5 Mon Sep 17 00:00:00 2001
From: Neil Roberts <neil@linux.intel.com>
Date: Wed, 21 Jul 2010 19:28:09 +0100
Subject: [PATCH] Add a shader which does a negation as one of the arguments to dot

This is basically doing:

 vec3 a_vec;
 vec3 b_vec;
 /* some random calculations */
 float result = dot(-a_vec, b_vec);

But for some reason it currently gets compiled as if it was:

 vec3 a_vec;
 vec3 b_vec;
 /* some random calculations */
 float result = dot(--a_vec, b_vec);

Ie, the negation gets done twice.

https://bugs.freedesktop.org/show_bug.cgi?id=29199
---
 tests/all.tests                           |    1 +
 tests/shaders/glsl-fs-neg-dot.shader_test |   33 +++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)
 create mode 100644 tests/shaders/glsl-fs-neg-dot.shader_test

diff --git a/tests/all.tests b/tests/all.tests
index de2cff0..28fdef3 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -355,6 +355,7 @@ add_plain_test(shaders, 'vp-ignore-input')
 add_plain_test(shaders, 'glsl-empty-vs-no-fs')
 add_plain_test(shaders, 'glsl-useprogram-displaylist')
 add_plain_test(shaders, 'glsl-vs-point-size')
+add_shader_generic(shaders, 'glsl-fs-neg')
 
 fpgeneric = Group()
 def add_fpgeneric(name):
diff --git a/tests/shaders/glsl-fs-neg-dot.shader_test b/tests/shaders/glsl-fs-neg-dot.shader_test
new file mode 100644
index 0000000..779a2ea
--- /dev/null
+++ b/tests/shaders/glsl-fs-neg-dot.shader_test
@@ -0,0 +1,33 @@
+[require]
+GL >= 2.0
+GLSL >= 1.10
+
+[vertex shader]
+void main()
+{
+	gl_Position = gl_Vertex;
+}
+
+[fragment shader]
+
+uniform vec3 vec_a;
+uniform vec3 vec_b;
+
+void main()
+{
+	/* This is just doing some random calculations. This should end up
+	   with tmp_vec = vec_a */
+	vec3 tmp_vec = vec_a * 3.0;
+	tmp_vec /= length (tmp_vec);
+	/* For some reason, tmp_vec here seems to get negated twice and
+	   the wrong value results */
+	float dot_value = dot(-tmp_vec, vec_b);
+	gl_FragColor.xyz = vec3 (dot_value);
+	gl_FragColor.a = 1.0;
+}
+
+[test]
+uniform vec3 vec_a 1.0 0.0 0.0
+uniform vec3 vec_b -1.0 0.0 0.0
+draw rect -1 -1 2 2
+probe rgb 1 1 1.0 1.0 1.0
-- 
1.7.1.87.g94e70