[dxvk] Add new vertex and geometry shaders for fullscreen passes

These new shaders are aimed to be used by all meta operations
and will work without geometry shaders on supported hardware.

src/dxvk/meson.build

@@ -24,6 +24,10 @@ dxvk_shaders = files([
   'shaders/dxvk_copy_depth_stencil_2d.frag',
   'shaders/dxvk_copy_depth_stencil_ms.frag',
 
+  'shaders/dxvk_fullscreen_geom.geom',
+  'shaders/dxvk_fullscreen_vert.vert',
+  'shaders/dxvk_fullscreen_layer_vert.vert',
+
   'shaders/dxvk_mipgen_vert.vert',
   'shaders/dxvk_mipgen_geom.geom',
   'shaders/dxvk_mipgen_frag_1d.frag',

src/dxvk/shaders/dxvk_fullscreen_geom.geom

@@ -0,0 +1,19 @@
+#version 450
+
+layout(triangles) in;
+layout(triangle_strip, max_vertices = 3) out;
+
+layout(location = 0) in  int  i_instance[3];
+layout(location = 1) in  vec2 i_texcoord[3];
+layout(location = 0) out vec2 o_texcoord;
+
+void main() {
+  for (int i = 0; i < 3; i++) {
+    o_texcoord  = i_texcoord[i];
+    gl_Layer    = i_instance[i];
+    gl_Position = gl_in[i].gl_Position;
+    EmitVertex();
+  }
+  
+  EndPrimitive();
+}

src/dxvk/shaders/dxvk_fullscreen_layer_vert.vert

@@ -0,0 +1,15 @@
+#version 450
+
+#extension GL_ARB_shader_viewport_layer_array : enable
+
+layout(location = 0) out vec2 o_texcoord;
+
+void main() {
+  vec2 coord = vec2(
+    float(gl_VertexIndex & 2),
+    float(gl_VertexIndex & 1) * 2.0f);
+
+  o_texcoord  = coord;
+  gl_Layer    = gl_InstanceIndex;
+  gl_Position = vec4(-1.0f + 2.0f * coord, 0.0f, 1.0f);
+}

src/dxvk/shaders/dxvk_fullscreen_vert.vert

@@ -0,0 +1,14 @@
+#version 450
+
+layout(location = 0) out int  o_instance;
+layout(location = 1) out vec2 o_texcoord;
+
+void main() {
+  vec2 coord = vec2(
+    float(gl_VertexIndex & 2),
+    float(gl_VertexIndex & 1) * 2.0f);
+
+  o_instance  = gl_InstanceIndex;
+  o_texcoord  = coord;
+  gl_Position = vec4(-1.0f + 2.0f * coord, 0.0f, 1.0f);
+}