5 files changed, 130 insertions, 1 deletions
diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index b52817c68a8..de4d59ad10b 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -133,6 +133,8 @@ data_to_c_simple(shaders/gpu_shader_flat_color_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_flat_color_alpha_test_0_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_widget_base_vert.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_2D_nodelink_frag.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_2D_nodelink_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_flat_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_line_dashed_uniform_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_line_dashed_frag.glsl SRC)
diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index 5041d524f18..486aea561c4 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -171,8 +171,10 @@ typedef enum GPUBuiltinShader {
 	GPU_SHADER_INSTANCE_VARIYING_COLOR_VARIYING_SIZE, /* Uniformly scaled */
 	GPU_SHADER_INSTANCE_VARIYING_COLOR_VARIYING_SCALE,
 	GPU_SHADER_INSTANCE_EDGES_VARIYING_COLOR,
-	/* specialized for widget drawing */
+	/* specialized for UI drawing */
 	GPU_SHADER_2D_WIDGET_BASE,
+	GPU_SHADER_2D_NODELINK,
+	GPU_SHADER_2D_NODELINK_INST,
 
 	GPU_SHADER_3D_INSTANCE_BONE_ENVELOPE_SOLID,
 	GPU_SHADER_3D_INSTANCE_BONE_ENVELOPE_WIRE,
diff --git a/source/blender/gpu/intern/gpu_shader.c b/source/blender/gpu/intern/gpu_shader.c
index 55184418284..c2f0aaf65de 100644
--- a/source/blender/gpu/intern/gpu_shader.c
+++ b/source/blender/gpu/intern/gpu_shader.c
@@ -68,6 +68,8 @@ extern char datatoc_gpu_shader_2D_image_vert_glsl[];
 extern char datatoc_gpu_shader_2D_image_rect_vert_glsl[];
 extern char datatoc_gpu_shader_2D_image_multi_rect_vert_glsl[];
 extern char datatoc_gpu_shader_2D_widget_base_vert_glsl[];
+extern char datatoc_gpu_shader_2D_nodelink_frag_glsl[];
+extern char datatoc_gpu_shader_2D_nodelink_vert_glsl[];
 
 extern char datatoc_gpu_shader_3D_image_vert_glsl[];
 extern char datatoc_gpu_shader_image_frag_glsl[];
@@ -799,6 +801,10 @@ GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader)
 
 		[GPU_SHADER_2D_WIDGET_BASE] = { datatoc_gpu_shader_2D_widget_base_vert_glsl,
 		                                datatoc_gpu_shader_2D_smooth_color_frag_glsl},
+		[GPU_SHADER_2D_NODELINK] = { datatoc_gpu_shader_2D_nodelink_vert_glsl,
+		                             datatoc_gpu_shader_2D_nodelink_frag_glsl },
+		[GPU_SHADER_2D_NODELINK_INST] = { datatoc_gpu_shader_2D_nodelink_vert_glsl,
+		                                  datatoc_gpu_shader_2D_nodelink_frag_glsl },
 
 		[GPU_SHADER_3D_INSTANCE_BONE_ENVELOPE_SOLID] = { datatoc_gpu_shader_instance_bone_envelope_solid_vert_glsl,
 		                                                 datatoc_gpu_shader_simple_lighting_frag_glsl },
@@ -813,6 +819,9 @@ GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader)
 		/* just a few special cases */
 		const char *defines = NULL;
 		switch (shader) {
+			case GPU_SHADER_2D_NODELINK_INST:
+				defines = "#define USE_INSTANCE;\n";
+				break;
 			case GPU_SHADER_SMOKE_COBA:
 				defines = "#define USE_COBA;\n";
 				break;
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
diff --git a/source/blender/gpu/shaders/gpu_shader_2D_nodelink_vert.glsl b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_vert.glsl
new file mode 100644
index 00000000000..3fcae15bf16
--- /dev/null
+++ b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_vert.glsl
@@ -0,0 +1,106 @@
+/**
+ * 2D Quadratic Bezier thick line drawing
+ **/
+
+#define MID_VERTEX 57
+
+/* u is position along the curve, defining the tangent space.
+ * v is "signed" distance (compressed to [0..1] range) from the pos in expand direction */
+in vec2 uv;
+in vec2 pos; /* verts position in the curve tangent space */
+in vec2 expand;
+
+#ifdef USE_INSTANCE
+/* Instance attrib */
+in vec2 P0;
+in vec2 P1;
+in vec2 P2;
+in vec2 P3;
+in ivec4 colid_doarrow;
+
+uniform vec4 colors[6];
+
+#define colStart   colors[colid_doarrow[0]]
+#define colEnd     colors[colid_doarrow[1]]
+#define colShadow  colors[colid_doarrow[2]]
+#define doArrow    (colid_doarrow[3] != 0)
+
+#else
+/* Single curve drawcall, use uniform. */
+uniform vec2 bezierPts[4];
+
+#define P0 bezierPts[0]
+#define P1 bezierPts[1]
+#define P2 bezierPts[2]
+#define P3 bezierPts[3]
+
+uniform vec4 colors[3];
+uniform bool doArrow;
+
+#define colShadow  colors[0]
+#define colStart   colors[1]
+#define colEnd     colors[2]
+
+#endif
+
+uniform float expandSize;
+uniform mat4 ModelViewProjectionMatrix;
+
+out float colorGradient;
+out vec4 finalColor;
+
+void main(void)
+{
+	float t = uv.x;
+	float t2 = t * t;
+	float t2_3 = 3.0 * t2;
+	float one_minus_t = 1.0 - t;
+	float one_minus_t2 = one_minus_t * one_minus_t;
+	float one_minus_t2_3 = 3.0 * one_minus_t2;
+
+	vec2 point = (P0 * one_minus_t2 * one_minus_t +
+	              P1 * one_minus_t2_3 * t +
+	              P2 * t2_3 * one_minus_t +
+	              P3 * t2 * t);
+
+	vec2 tangent = ((P1 - P0) * one_minus_t2_3 +
+	                (P2 - P1) * 6.0 * (t - t2) +
+	                (P3 - P2) * t2_3);
+
+	/* tangent space at t */
+	tangent = normalize(tangent);
+	vec2 normal = tangent.yx * vec2(-1.0, 1.0);
+
+	/* Position vertex on the curve tangent space */
+	point += pos.x * tangent + pos.y * normal;
+
+	gl_Position = ModelViewProjectionMatrix * vec4(point, 0.0, 1.0);
+
+	vec2 exp_axis = expand.x * tangent + expand.y * normal;
+
+	/* rotate & scale the expand axis */
+	exp_axis = ModelViewProjectionMatrix[0].xy * exp_axis.xx +
+	           ModelViewProjectionMatrix[1].xy * exp_axis.yy;
+
+
+	float expand_dist = (uv.y * 2.0 - 1.0);
+	colorGradient = expand_dist;
+
+	if (gl_VertexID < MID_VERTEX) {
+		/* Shadow pass */
+		finalColor = colShadow;
+	}
+	else {
+		/* Second pass */
+		finalColor = mix(colStart, colEnd, uv.x);
+		expand_dist *= 0.5;
+	}
+
+	/* Expand into a line */
+	gl_Position.xy += exp_axis * expandSize * expand_dist;
+
+	/* if arrow */
+	if (expand.y != 1.0 && !doArrow) {
+		gl_Position.xy *= 0.0;
+	}
+}
+\ No newline at end of file