Add remaining GLSL version directives

Related to #864.

examples/offscreen.c

@@ -51,6 +51,7 @@ static const struct
 };
 
 static const char* vertex_shader_text =
+"#version 110\n"
 "uniform mat4 MVP;\n"
 "attribute vec3 vCol;\n"
 "attribute vec2 vPos;\n"
@@ -62,6 +63,7 @@ static const char* vertex_shader_text =
 "}\n";
 
 static const char* fragment_shader_text =
+"#version 110\n"
 "varying vec3 color;\n"
 "void main()\n"
 "{\n"

examples/simple.c

@@ -44,6 +44,7 @@ static const struct
 };
 
 static const char* vertex_shader_text =
+"#version 110\n"
 "uniform mat4 MVP;\n"
 "attribute vec3 vCol;\n"
 "attribute vec2 vPos;\n"
@@ -55,6 +56,7 @@ static const char* vertex_shader_text =
 "}\n";
 
 static const char* fragment_shader_text =
+"#version 110\n"
 "varying vec3 color;\n"
 "void main()\n"
 "{\n"

tests/msaa.c

@@ -53,6 +53,7 @@ static const vec2 vertices[4] =
 };
 
 static const char* vertex_shader_text =
+"#version 110\n"
 "uniform mat4 MVP;\n"
 "attribute vec2 vPos;\n"
 "void main()\n"
@@ -61,6 +62,7 @@ static const char* vertex_shader_text =
 "}\n";
 
 static const char* fragment_shader_text =
+"#version 110\n"
 "void main()\n"
 "{\n"
 "    gl_FragColor = vec4(1.0);\n"

tests/reopen.c

@@ -43,6 +43,7 @@
 #include "linmath.h"
 
 static const char* vertex_shader_text =
+"#version 110\n"
 "uniform mat4 MVP;\n"
 "attribute vec2 vPos;\n"
 "void main()\n"
@@ -51,6 +52,7 @@ static const char* vertex_shader_text =
 "}\n";
 
 static const char* fragment_shader_text =
+"#version 110\n"
 "void main()\n"
 "{\n"
 "    gl_FragColor = vec4(1.0);\n"

tests/tearing.c

@@ -50,6 +50,7 @@ static const struct
 };
 
 static const char* vertex_shader_text =
+"#version 110\n"
 "uniform mat4 MVP;\n"
 "attribute vec2 vPos;\n"
 "void main()\n"
@@ -58,6 +59,7 @@ static const char* vertex_shader_text =
 "}\n";
 
 static const char* fragment_shader_text =
+"#version 110\n"
 "void main()\n"
 "{\n"
 "    gl_FragColor = vec4(1.0);\n"