Add AT_LIGHT_PASS builtin to canvas shaders

This one allows for complex shaders paired with a simple lighting shader to skip code that would otherwise be pointlessly (and wastefully) run during the light pass.

Depending on your game (number of items and lights), this can yield some performance gain.

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gles3/shader_compiler_gles3.cpp b/drivers/gles3/shader_compiler_gles3.cpp
index b1f7b4c9bd..3376f99112 100644
--- a/drivers/gles3/shader_compiler_gles3.cpp
+++ b/drivers/gles3/shader_compiler_gles3.cpp
@@ -668,6 +668,7 @@ ShaderCompilerGLES3::ShaderCompilerGLES3() {
 	actions[VS::SHADER_CANVAS_ITEM].renames["PROJECTION_MATRIX"] = "projection_matrix";
 	actions[VS::SHADER_CANVAS_ITEM].renames["EXTRA_MATRIX"] == "extra_matrix";
 	actions[VS::SHADER_CANVAS_ITEM].renames["TIME"] = "time";
+	actions[VS::SHADER_CANVAS_ITEM].renames["AT_LIGHT_PASS"] = "at_light_pass";
 
 	actions[VS::SHADER_CANVAS_ITEM].renames["COLOR"] = "color";
 	actions[VS::SHADER_CANVAS_ITEM].renames["NORMAL"] = "normal";
diff --git a/drivers/gles3/shaders/canvas.glsl b/drivers/gles3/shaders/canvas.glsl
index 017009015e..31fea8237a 100644
--- a/drivers/gles3/shaders/canvas.glsl
+++ b/drivers/gles3/shaders/canvas.glsl
@@ -59,6 +59,9 @@ out vec4 local_rot;
 out highp vec2 pos;
 #endif
 
+const bool at_light_pass = true;
+#else
+const bool at_light_pass = false;
 #endif
 
 
@@ -191,6 +194,9 @@ in highp vec2 pos;
 
 #endif
 
+const bool at_light_pass = true;
+#else
+const bool at_light_pass = false;
 #endif
 
 uniform mediump vec4 final_modulate;