Add shader module.

* 2d/shader.scm: New module.
* Makefile.am: Add 2d/shader.scm to SOURCES.
* examples/shader.scm: New example.
* examples/shaders/fragment-shader.glsl: New shader.
* examples/shaders/vertex-shader.glsl: New shader.

2 files changed, 20 insertions, 0 deletions

diff --git a/examples/shaders/fragment-shader.glsl b/examples/shaders/fragment-shader.glsl
new file mode 100644
index 0000000..9be52f0
--- /dev/null
+++ b/examples/shaders/fragment-shader.glsl
@@ -0,0 +1,7 @@
+#version 120
+
+uniform sampler2D color_texture;
+
+void main (void) {
+    gl_FragColor = texture2D(color_texture, gl_TexCoord[0].st);
+}
diff --git a/examples/shaders/vertex-shader.glsl b/examples/shaders/vertex-shader.glsl
new file mode 100644
index 0000000..2a7a4a4
--- /dev/null
+++ b/examples/shaders/vertex-shader.glsl
@@ -0,0 +1,13 @@
+#version 120
+
+uniform float angle;
+
+void main(void) {
+    mat4 RotationMatrix = mat4(cos(angle), -sin(angle), 0.0, 0.0,
+                               sin(angle), cos(angle),  0.0, 0.0,
+                               0.0,        0.0,         1.0, 0.0,
+                               0.0,        0.0,         0.0, 1.0);
+
+    gl_Position =  gl_ModelViewProjectionMatrix * RotationMatrix * gl_Vertex;
+    gl_TexCoord[0] = gl_MultiTexCoord0;
+}