[gtk/wip.win32.fixes: 12/13] gskglcompiler.c: Set version as appropriate for GLES 3.0+ contexts

[Chun-wei Fan <fanchunwei src gnome org>]

commit 0ab3ebbeddf4fa6620110ede772a538978198aa3
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Nov 25 16:09:50 2021 +0800

    gskglcompiler.c: Set version as appropriate for GLES 3.0+ contexts
    
    Instead of just using "300 es" as the shader target version for libANGLE
    GLES contexts, just apply that whenever we are using GLES 3.0+ contexts.
    
    Also simplify the code by making ->glsl_version a const char* and make
    the existing macros defined appropriately, and add a new macro for the
    "300 es" version string.

 gsk/gl/gskglcompiler.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)
---
diff --git a/gsk/gl/gskglcompiler.c b/gsk/gl/gskglcompiler.c
index 30f2ae585d..70a2da24ad 100644
--- a/gsk/gl/gskglcompiler.c
+++ b/gsk/gl/gskglcompiler.c
@@ -28,10 +28,11 @@
 #include "gskglcompilerprivate.h"
 #include "gskglprogramprivate.h"
 
-#define SHADER_VERSION_GLES       100
-#define SHADER_VERSION_GL2_LEGACY 110
-#define SHADER_VERSION_GL3_LEGACY 130
-#define SHADER_VERSION_GL3        150
+#define SHADER_VERSION_GLES       "100"
+#define SHADER_VERSION_GLES3      "300 es"
+#define SHADER_VERSION_GL2_LEGACY "110"
+#define SHADER_VERSION_GL3_LEGACY "130"
+#define SHADER_VERSION_GL3        "150"
 
 struct _GskGLCompiler
 {
@@ -49,11 +50,11 @@ struct _GskGLCompiler
 
   GArray *attrib_locations;
 
-  int glsl_version;
+  const char *glsl_version;
 
   guint gl3 : 1;
   guint gles : 1;
-  guint force_glsl_300es : 1;
+  guint use_glsl_300es : 1;
   guint legacy : 1;
   guint debug_shaders : 1;
 };
@@ -99,7 +100,7 @@ gsk_gl_compiler_class_init (GskGLCompilerClass *klass)
 static void
 gsk_gl_compiler_init (GskGLCompiler *self)
 {
-  self->glsl_version = 150;
+  self->glsl_version = "150";
   self->attrib_locations = g_array_new (FALSE, FALSE, sizeof (GskGLProgramAttrib));
   self->all_preamble = g_bytes_ref (empty_bytes);
   self->vertex_preamble = g_bytes_ref (empty_bytes);
@@ -128,10 +129,13 @@ gsk_gl_compiler_new (GskGLDriver *driver,
 
   if (gdk_gl_context_get_use_es (context))
     {
-      /* for libANGLE to work with our shaders, we must use 300 es as our shader version */
-      self->force_glsl_300es =
-        (strncmp ("ANGLE ", (const char *) glGetString (GL_RENDERER), 6) == 0);
-      self->glsl_version = SHADER_VERSION_GLES;
+      int maj, min;
+
+      /* for OpenGL/ES 3.0+, use "300 es" as our shader version */
+      gdk_gl_context_get_version (context, &maj, &min);
+      self->use_glsl_300es = (maj >= 3);
+
+      self->glsl_version = self->use_glsl_300es ? SHADER_VERSION_GLES3 : SHADER_VERSION_GLES;
       self->gles = TRUE;
     }
   else if (gdk_gl_context_is_legacy (context))
@@ -551,10 +555,7 @@ gsk_gl_compiler_compile (GskGLCompiler  *self,
 
   gsk_gl_command_queue_make_current (self->driver->command_queue);
 
-  if (self->force_glsl_300es)
-    g_snprintf (version, sizeof version, "#version 300 es\n");
-  else
-    g_snprintf (version, sizeof version, "#version %d\n", self->glsl_version);
+  g_snprintf (version, sizeof version, "#version %s\n", self->glsl_version);
 
   if (self->debug_shaders)
     debug = "#define GSK_DEBUG 1\n";
@@ -564,7 +565,7 @@ gsk_gl_compiler_compile (GskGLCompiler  *self,
 
   if (self->gles)
     {
-      if (self->force_glsl_300es)
+      if (self->use_glsl_300es)
         gles = "#define GSK_GLES3 1\n";
       else
         gles = "#define GSK_GLES 1\n";