TextureCache: Add R16G16 to D24S8 converter.

src/video_core/host_shaders/CMakeLists.txt

@@ -17,6 +17,7 @@ set(SHADER_FILES
     convert_d24s8_to_r16g16.frag
     convert_depth_to_float.frag
     convert_float_to_depth.frag
+    convert_r16g16_to_d24s8.frag
     full_screen_triangle.vert
     fxaa.frag
     fxaa.vert

src/video_core/host_shaders/convert_r16g16_to_d24s8.frag

@@ -0,0 +1,18 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#version 450
+// #extension GL_ARB_shader_stencil_export : require
+
+layout(binding = 0) uniform sampler2D color_texture;
+
+void main() {
+    ivec2 coord = ivec2(gl_FragCoord.xy);
+    vec4 color = texelFetch(color_texture, coord, 0).rgba;
+    uint depth_stencil_unorm = (uint(color.r * (exp2(16) - 1.0f)) << 16)
+                      | (uint(color.g * (exp2(16) - 1.0f)) << 16);
+
+    gl_FragDepth = float(depth_stencil_unorm >> 8) / (exp2(24.0) - 1.0f);
+    // gl_FragStencilRefARB = int(depth_stencil_unorm & 0x00FF);
+}