Supply ES2 versions of the default material shaders

This also means that the building of the default material has
to be delayed until the OpenGL context is known.

Change-Id: I09c0db35a035cb1cfd16b564071445c2dcd4e53c
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

2 files changed, 39 insertions, 0 deletions

diff --git a/src/render/shaders/es2/diffuse.frag b/src/render/shaders/es2/diffuse.frag
new file mode 100644
index 000000000..b9c7c8919
--- /dev/null
+++ b/src/render/shaders/es2/diffuse.frag
@@ -0,0 +1,22 @@
+#define FP highp
+
+uniform FP vec4 lightPosition;
+uniform FP vec3 lightIntensity;
+uniform FP vec3 kd; // Diffuse reflectivity
+uniform FP vec3 ka; // Ambient reflectivity
+
+varying FP vec3 position;
+varying FP vec3 normal;
+
+void main()
+{
+    // Calculate the vector from the light to the fragment
+    FP vec3 s = normalize( vec3( lightPosition ) - position );
+
+    // Calculate the diffuse lighting factor
+    FP vec3 n = normalize( normal );
+    FP float diffuse = max( dot( s, n ), 0.0 );
+
+    // Multiply by incoming light intensity
+    gl_FragColor = vec4( lightIntensity * (kd * diffuse + ka), 1.0 );
+}
diff --git a/src/render/shaders/es2/diffuse.vert b/src/render/shaders/es2/diffuse.vert
new file mode 100644
index 000000000..255af8f11
--- /dev/null
+++ b/src/render/shaders/es2/diffuse.vert
@@ -0,0 +1,17 @@
+attribute vec3 vertexPosition;
+attribute vec3 vertexNormal;
+
+varying vec3 position;
+varying vec3 normal;
+
+uniform mat4 modelView;
+uniform mat3 modelViewNormal;
+uniform mat4 modelViewProjection;
+
+void main()
+{
+    normal = normalize( modelViewNormal * vertexNormal );
+    position = vec3( modelView * vec4( vertexPosition, 1.0 ) );
+
+    gl_Position = modelViewProjection * vec4( vertexPosition, 1.0 );
+}