[oden] Color and position for text

src/text_shader.wgsl

@@ -12,16 +12,19 @@ struct InstanceInput {
   @location(6) src_dims: vec2<f32>,
   @location(7) dest_top_left: vec2<f32>,
   @location(8) dest_dims: vec2<f32>,
+  @location(9) color: vec4<f32>,
 };
 
 struct VertexOutput {
   @builtin(position) clip_position : vec4<f32>,
   @location(0) tex_coords : vec2<f32>,
+  @location(1) color: vec4<f32>,
 };
 
 @vertex fn vs_main(vertex : VertexInput, instance : InstanceInput)->VertexOutput {
   var out : VertexOutput;
   out.tex_coords = instance.src_top_left + (vertex.tex_coords * instance.src_dims);
+  out.color = instance.color;
 
   let in_pos = instance.dest_top_left + (vec2f(vertex.position.x, vertex.position.y) * instance.dest_dims);
 
@@ -38,16 +41,22 @@ struct VertexOutput {
 @group(1) @binding(1) var s_diffuse : sampler;
 
 @fragment fn fs_main(in : VertexOutput)->@location(0) vec4<f32> {
-  // TODO: Should we be sampling here for the shader?
-
   let tc = vec2(u32(in.tex_coords.x), u32(in.tex_coords.y));
   let c = textureLoad(t_diffuse, tc, 0);
 
+  // If we were going to run this through the sampler it would look like
+  // this... but I don't know if that'w what we should do? Right now the
+  // direct load looks better?
+  //
   // let tc = in.tex_coords / vec2<f32>(textureDimensions(t_diffuse));
   // let c = textureSample(t_diffuse, s_diffuse, tc);  
 
-
-  return vec4<f32>(c.r,c.r,c.r,c.r);
+  return vec4<f32>(
+      c.r * in.color.x,
+      c.r * in.color.y,
+      c.r * in.color.z,
+      c.r * in.color.a
+  );
   //return vec4<f32>(1.0,1.0,1.0,1.0);
 }