Revive the WebGL backend

Always declare the clip buffer when using
WEBGL_shader_pixel_local_storage. The spec requires the shader to explicitly declare every plane that has been enabled.

Also fix some bit-rot in path_fiddle.

Diffs=
e1b4a53ec Revive the WebGL backend (#7948)

Co-authored-by: Chris Dalton <99840794+csmartdalton@users.noreply.github.com>

.rive_head

@@ -1 +1 @@
-813db58e71b442a83574745cf6cc29e5d885b403
+e1b4a53ecb34d62e9d4160e3040803173c2233b0

pls/path_fiddle/fiddle_context_gl.cpp

@@ -1,6 +1,6 @@
 #include "fiddle_context.hpp"
 
-#ifndef RIVE_DESKTOP_GL
+#ifdef RIVE_TOOLS_NO_GLFW
 
 std::unique_ptr<FiddleContext> FiddleContext::MakeGLPLS() { return nullptr; }
 
@@ -109,7 +109,7 @@ class FiddleContextGL : public FiddleContext
 
     float dpiScale(GLFWwindow*) const override
     {
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(RIVE_WEBGL)
         return 2;
 #else
         return 1;

pls/renderer/shaders/draw_image_mesh.glsl

@@ -98,7 +98,7 @@ FRAG_STORAGE_BUFFER_BLOCK_END
 
 PLS_BLOCK_BEGIN
 PLS_DECL4F(COLOR_PLANE_IDX, colorBuffer);
-#ifdef @ENABLE_CLIPPING
+#if defined(@ENABLE_CLIPPING) || defined(@PLS_IMPL_ANGLE)
 PLS_DECLUI(CLIP_PLANE_IDX, clipBuffer);
 #endif
 PLS_DECL4F(SCRATCH_COLOR_PLANE_IDX, scratchColorBuffer);

pls/renderer/shaders/draw_path.glsl

@@ -309,7 +309,7 @@ INLINE half4 find_paint_color(float4 paint
 
 PLS_BLOCK_BEGIN
 PLS_DECL4F(COLOR_PLANE_IDX, colorBuffer);
-#ifdef @ENABLE_CLIPPING
+#if defined(@ENABLE_CLIPPING) || defined(@PLS_IMPL_ANGLE)
 PLS_DECLUI(CLIP_PLANE_IDX, clipBuffer);
 #endif
 PLS_DECL4F(SCRATCH_COLOR_PLANE_IDX, scratchColorBuffer);