OpenSubdiv: Split shader source files

Was a bit annoying to do tweaks in a file which contained all
vertex, geometry and fragment shaders.

intern/opensubdiv/gpu_shader_opensubdiv_geometry.glsl

@@ -0,0 +1,165 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2014 Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Sergey Sharybin
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+struct VertexData {
+	vec4 position;
+	vec3 normal;
+	vec2 uv;
+};
+
+#if __VERSION__ >= 150
+layout(lines_adjacency) in;
+  #ifdef WIREFRAME
+layout(line_strip, max_vertices = 8) out;
+  #else
+layout(triangle_strip, max_vertices = 4) out;
+  #endif
+#else
+  #extension GL_EXT_geometry_shader4: require
+  /* application provides input/output layout info */
+#endif
+
+#if __VERSION__ < 140
+  #extension GL_ARB_uniform_buffer_object: require
+  #extension GL_ARB_texture_buffer_object: enable
+  #extension GL_EXT_texture_buffer_object: enable
+#endif
+
+uniform mat4 modelViewMatrix;
+uniform mat4 projectionMatrix;
+uniform int PrimitiveIdBase;
+uniform int osd_fvar_count;
+uniform int osd_active_uv_offset;
+
+in block {
+	VertexData v;
+} inpt[];
+
+#define INTERP_FACE_VARYING_2(result, fvarOffset, tessCoord)  \
+	{ \
+		vec2 v[4]; \
+		int primOffset = (gl_PrimitiveID + PrimitiveIdBase) * 4; \
+		for (int i = 0; i < 4; ++i) { \
+			int index = (primOffset + i) * osd_fvar_count + fvarOffset; \
+			v[i] = vec2(texelFetch(FVarDataBuffer, index).s, \
+			            texelFetch(FVarDataBuffer, index + 1).s); \
+		} \
+		result = mix(mix(v[0], v[1], tessCoord.s), \
+		             mix(v[3], v[2], tessCoord.s), \
+		             tessCoord.t); \
+	}
+
+uniform samplerBuffer FVarDataBuffer;
+uniform isamplerBuffer FVarDataOffsetBuffer;
+
+out block {
+	VertexData v;
+} outpt;
+
+#ifdef FLAT_SHADING
+void emit(int index, vec3 normal)
+{
+	outpt.v.position = inpt[index].v.position;
+	outpt.v.normal = normal;
+
+	/* TODO(sergey): Only uniform subdivisions atm. */
+	vec2 quadst[4] = vec2[](vec2(0, 0), vec2(1, 0), vec2(1, 1), vec2(0, 1));
+	vec2 st = quadst[index];
+
+	INTERP_FACE_VARYING_2(outpt.v.uv, osd_active_uv_offset, st);
+
+	gl_Position = projectionMatrix * inpt[index].v.position;
+	EmitVertex();
+}
+
+#  ifdef WIREFRAME
+void emit_edge(int v0, int v1, vec3 normal)
+{
+	emit(v0, normal);
+	emit(v1, normal);
+}
+#  endif
+
+#else
+void emit(int index)
+{
+	outpt.v.position = inpt[index].v.position;
+	outpt.v.normal = inpt[index].v.normal;
+
+	/* TODO(sergey): Only uniform subdivisions atm. */
+	vec2 quadst[4] = vec2[](vec2(0, 0), vec2(1, 0), vec2(1, 1), vec2(0, 1));
+	vec2 st = quadst[index];
+
+	INTERP_FACE_VARYING_2(outpt.v.uv, osd_active_uv_offset, st);
+
+	gl_Position = projectionMatrix * inpt[index].v.position;
+	EmitVertex();
+}
+
+#  ifdef WIREFRAME
+void emit_edge(int v0, int v1)
+{
+	emit(v0);
+	emit(v1);
+}
+#  endif
+
+#endif
+
+void main()
+{
+	gl_PrimitiveID = gl_PrimitiveIDIn;
+
+#ifdef FLAT_SHADING
+	vec3 A = (inpt[0].v.position - inpt[1].v.position).xyz;
+	vec3 B = (inpt[3].v.position - inpt[1].v.position).xyz;
+	vec3 flat_normal = normalize(cross(B, A));
+#  ifndef WIREFRAME
+	emit(0, flat_normal);
+	emit(1, flat_normal);
+	emit(3, flat_normal);
+	emit(2, flat_normal);
+#  else
+	emit_edge(0, 1, flat_normal);
+	emit_edge(1, 2, flat_normal);
+	emit_edge(2, 3, flat_normal);
+	emit_edge(3, 0, flat_normal);
+#  endif
+#else
+#  ifndef WIREFRAME
+	emit(0);
+	emit(1);
+	emit(3);
+	emit(2);
+#  else
+	emit_edge(0, 1);
+	emit_edge(1, 2);
+	emit_edge(2, 3);
+	emit_edge(3, 0);
+#  endif
+#endif
+
+	EndPrimitive();
+}