Implement cubic bezier surfaceHEADmaster

1 files changed, 16 insertions, 9 deletions

diff --git a/data/simple.vert b/data/simple.vert
index 1850a67..6fdb13b 100644
--- a/data/simple.vert
+++ b/data/simple.vert
@@ -3,6 +3,7 @@
 
 uniform mat4 mvp;
 uniform mat3 mv_normal;
+uniform mat4x3 k_uniform[4];
 
 layout(location = 0) in vec2 uv;
 
@@ -14,15 +15,21 @@ out vec3 normal_cs;
 
 void main(void)
 {
-	/* Center the region at the origin.  Assume that it's 7 units by 7
-	 * units.
-	 */
-	vec2 bias_uv = uv - 0.5;
-	vec4 position = vec4(bias_uv.x * 7.,
-			     0.0,
-			     bias_uv.y * 7.,
-			     1.0);
-	gl_Position = mvp * position;
+	vec4 uhat = vec4((1 - uv.x) * (1 - uv.x) * (1 - uv.x),
+			 3. * uv.x * (1 - uv.x) * (1 - uv.x),
+			 3. * uv.x * uv.x * (1 - uv.x),
+			 uv.x * uv.x * uv.x);
+	vec4 vhat = vec4((1 - uv.y) * (1 - uv.y) * (1 - uv.y),
+			 3. * uv.y * (1 - uv.y) * (1 - uv.y),
+			 3. * uv.y * uv.y * (1 - uv.y),
+			 uv.y * uv.y * uv.y);
+	mat4x3 m;
+	m[0] = k_uniform[0] * uhat;
+	m[1] = k_uniform[1] * uhat;
+	m[2] = k_uniform[2] * uhat;
+	m[3] = k_uniform[3] * uhat;
+
+	gl_Position = mvp * vec4(m * vhat, 1.0);
 
 	/* Transform the normal by the inverse-transpose of the model-view
 	 * matrix.