Added an example of fullscreen shader effects with the GPU renderer

test/build-shaders.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -e
+
+make-header() {
+    xxd -i "$1" | sed \
+        -e 's/^unsigned /const unsigned /g' \
+        -e 's,^const,static const,' \
+        > "$1.h"
+}
+
+# Requires shadercross CLI installed from SDL_shadercross
+for filename in *.hlsl; do
+    if [ -f "$filename" ]; then
+        shadercross "$filename" -o "${filename/.hlsl/.spv}"
+        make-header "${filename/.hlsl/.spv}"
+        shadercross "$filename" -o "${filename/.hlsl/.msl}"
+        make-header "${filename/.hlsl/.msl}"
+        shadercross "$filename" -o "${filename/.hlsl/.dxil}"
+        make-header "${filename/.hlsl/.dxil}"
+    fi
+done
+
+rm -f *.spv *.msl *.dxil