vulkan: also support glslang as a shader compiler

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6980>

subprojects/gst-plugins-bad/ext/vulkan/meson.build

@@ -23,10 +23,11 @@ vulkan_sources = files(
 )
 vulkan_plugin_enums = []
 
-glslc = find_program('glslc', required: get_option('vulkan'))
-if not glslc.found()
+glslc = find_program('glslc', required: false)
+glslang = find_program('glslang', required: false)
+if not glslc.found() and not glslang.found()
   if get_option('vulkan').enabled()
-    error('GStreamer Vulkan plugin required via options, but glslc was not found.')
+    error('GStreamer Vulkan plugin required via options, but glslc or glslang was not found.')
   else
     subdir_done()
   endif

subprojects/gst-plugins-bad/ext/vulkan/shaders/ayuv_to_rgb.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "upsample_ayuv.glsl"
 #include "swizzle.glsl"

subprojects/gst-plugins-bad/ext/vulkan/shaders/meson.build

@@ -16,19 +16,36 @@ gst_vulkan_shader_sources = [
 bin2array = find_program('bin2array.py')
 
 # FIXME: meson compiler class instead?
-glslc_build_options = []
-optimization = get_option('optimization')
-if get_option('debug')
-  glslc_build_options += ['-g']
-endif
-if get_option('werror')
-  glslc_build_options += ['-Werror']
-endif
-if optimization == 's'
-  glslc_build_options += ['-Os']
-endif
-if optimization in ['1', '2', '3']
-  glslc_build_options += ['-O']
+if glslc.found()
+  glslc_build_options = []
+  optimization = get_option('optimization')
+  if get_option('debug')
+    glslc_build_options += ['-g']
+  endif
+  if get_option('werror')
+    glslc_build_options += ['-Werror']
+  endif
+  if optimization == 's'
+    glslc_build_options += ['-Os']
+  endif
+  if optimization in ['1', '2', '3']
+    glslc_build_options += ['-O']
+  endif
+elif glslang.found()
+  glslang_build_options = []
+  optimization = get_option('optimization')
+  if get_option('debug')
+    glslang_build_options += ['-g']
+  endif
+  if optimization == 's'
+    glslang_build_options += ['-Os']
+  endif
+  if optimization == '0'
+    glslang_build_options += ['-Od']
+  endif
+else
+  error('No glslc or glslang!')
+  subdir_done()
 endif
 
 vulkan_compiled_shader_sources = []
@@ -36,21 +53,36 @@ foreach shader: gst_vulkan_shader_sources
   basefn = shader.split('.').get(0)
   suffix = shader.split('.').get(1)
 
-  stage_arg = suffix == 'frag' ? '-fshader-stage=fragment' : '-fshader-stage=vertex'
   basename = '@0@.@1@'.format(basefn, suffix)
   spv_shader = basename + '.spv'
   c_shader_source = basename + '.c'
   c_shader_header = basename + '.h'
 
-  compiled_shader = custom_target(spv_shader,
-      input: shader,
-      output: spv_shader,
-      depfile: '@PLAINNAME@.d',
-      command: [glslc] + glslc_build_options + [stage_arg,
-        '--target-env=vulkan1.0',
-        '-MD', '-MF', '@DEPFILE@',
-        '@INPUT@',
-        '-o', '@OUTPUT@'])
+  if glslc.found()
+    stage_arg = suffix == 'frag' ? '-fshader-stage=fragment' : '-fshader-stage=vertex'
+    compiled_shader = custom_target(spv_shader,
+        input: shader,
+        output: spv_shader,
+        depfile: '@PLAINNAME@.d',
+        command: [glslc] + glslc_build_options + [stage_arg,
+          '--target-env=vulkan1.0',
+          '-MD', '-MF', '@DEPFILE@',
+          '@INPUT@',
+          '-o', '@OUTPUT@'])
+  elif glslang.found()
+    compiled_shader = custom_target(spv_shader,
+        input: shader,
+        output: spv_shader,
+        depfile: '@PLAINNAME@.d',
+        command: [glslang] + glslang_build_options + [
+          '-V100',
+          '-I' + meson.current_source_dir(),
+          '--target-env', 'vulkan1.0',
+          '--depfile', '@DEPFILE@',
+          '--quiet',
+          '@INPUT@',
+          '-o', '@OUTPUT@'])
+  endif
 
   c_shader = custom_target (c_shader_source,
       input: compiled_shader,

subprojects/gst-plugins-bad/ext/vulkan/shaders/nv12_to_rgb.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "upsample_nv12.glsl"
 #include "swizzle.glsl"

subprojects/gst-plugins-bad/ext/vulkan/shaders/rgb_to_ayuv.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "swizzle.glsl"
 

subprojects/gst-plugins-bad/ext/vulkan/shaders/rgb_to_nv12.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "swizzle.glsl"
 

subprojects/gst-plugins-bad/ext/vulkan/shaders/rgb_to_yuy2.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "swizzle.glsl"
 

subprojects/gst-plugins-bad/ext/vulkan/shaders/swizzle.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "swizzle.glsl"
 
 layout(location = 0) in vec2 inTexCoord;

subprojects/gst-plugins-bad/ext/vulkan/shaders/swizzle_and_clobber_alpha.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "swizzle.glsl"
 
 layout(location = 0) in vec2 inTexCoord;

subprojects/gst-plugins-bad/ext/vulkan/shaders/view_convert.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "view_defines.h"
 #include "swizzle.glsl"
 

subprojects/gst-plugins-bad/ext/vulkan/shaders/yuy2_to_rgb.frag

@@ -19,6 +19,8 @@
 
 #version 450 core
 
+#extension GL_GOOGLE_include_directive : enable
+
 #include "color_convert_generic.glsl"
 #include "upsample_yuy2.glsl"
 #include "swizzle.glsl"