GPUShader: Add 2D Nodelink shader.

Special shader to draw nodelinks for the node editor.

We only pass bezier points to the GPU and vertex position is handled inside
the vertex shader.
The arrow is also part of the batch to avoid separate drawcalls for it.

We still draw 2 pass one for shadow and one for the link color on top.

One variation to draw instances of theses links so that we only do one
drawcall.

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl
new file mode 100644
index 00000000000..8dda575107a
--- /dev/null
+++ b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl
@@ -0,0 +1,10 @@
+
+in float colorGradient;
+in vec4 finalColor;
+
+out vec4 fragColor;
+
+void main() {
+	fragColor = finalColor;
+	fragColor.a *= smoothstep(1.0, 0.1, abs(colorGradient));
+}
\ No newline at end of file