Reduce shader permutations in the compatibility backend

drivers/gles3/rasterizer_canvas_gles3.cpp

@@ -687,6 +687,8 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 
 	state.current_tex = RID();
 
+	const uint64_t base_specialization = GLES3::Config::get_singleton()->float_texture_supported ? 0 : CanvasShaderGLES3::USE_RGBA_SHADOWS;
+
 	for (uint32_t i = 0; i <= state.current_batch_index; i++) {
 		// Skipping when there is no instances.
 		if (state.canvas_instance_batches[i].instance_count == 0) {
@@ -705,10 +707,9 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 		}
 
 		GLES3::CanvasMaterialData *material_data = state.canvas_instance_batches[i].material_data;
-		CanvasShaderGLES3::ShaderVariant variant = state.canvas_instance_batches[i].shader_variant;
-		uint64_t specialization = 0;
-		specialization |= uint64_t(state.canvas_instance_batches[i].lights_disabled);
-		specialization |= uint64_t(!GLES3::Config::get_singleton()->float_texture_supported) << 1;
+		CanvasShaderGLES3::ShaderVariant variant = CanvasShaderGLES3::MODE_DEFAULT;
+		uint64_t specialization = state.canvas_instance_batches[i].specialization;
+		specialization |= base_specialization;
 		RID shader_version = data.canvas_shader_default_version;
 
 		if (material_data) {
@@ -810,6 +811,7 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 
 void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_render_target, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, GLES3::CanvasShaderData::BlendMode p_blend_mode, Light *p_lights, uint32_t &r_index, bool &r_batch_broken, bool &r_sdf_used, const Point2 &p_repeat_offset) {
 	RenderingServer::CanvasItemTextureFilter texture_filter = p_item->texture_filter == RS::CANVAS_ITEM_TEXTURE_FILTER_DEFAULT ? state.default_filter : p_item->texture_filter;
+	const uint64_t specialization_command_mask = ~(CanvasShaderGLES3::USE_NINEPATCH | CanvasShaderGLES3::USE_PRIMITIVE | CanvasShaderGLES3::USE_ATTRIBUTES | CanvasShaderGLES3::USE_INSTANCING);
 
 	if (texture_filter != state.canvas_instance_batches[state.current_batch_index].filter) {
 		_new_batch(r_batch_broken);
@@ -868,9 +870,9 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 
 	bool lights_disabled = light_count == 0 && !state.using_directional_lights;
 
-	if (lights_disabled != state.canvas_instance_batches[state.current_batch_index].lights_disabled) {
+	if (lights_disabled != bool(state.canvas_instance_batches[state.current_batch_index].specialization & CanvasShaderGLES3::DISABLE_LIGHTING)) {
 		_new_batch(r_batch_broken);
-		state.canvas_instance_batches[state.current_batch_index].lights_disabled = lights_disabled;
+		state.canvas_instance_batches[state.current_batch_index].specialization ^= CanvasShaderGLES3::DISABLE_LIGHTING;
 	}
 
 	const Item::Command *c = p_item->commands;
@@ -936,7 +938,7 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 					state.canvas_instance_batches[state.current_batch_index].tex = rect->texture;
 					state.canvas_instance_batches[state.current_batch_index].command_type = Item::Command::TYPE_RECT;
 					state.canvas_instance_batches[state.current_batch_index].command = c;
-					state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_QUAD;
+					state.canvas_instance_batches[state.current_batch_index].specialization &= specialization_command_mask;
 				}
 
 				_prepare_canvas_texture(rect->texture, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
@@ -1026,7 +1028,8 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 					state.canvas_instance_batches[state.current_batch_index].tex = np->texture;
 					state.canvas_instance_batches[state.current_batch_index].command_type = Item::Command::TYPE_NINEPATCH;
 					state.canvas_instance_batches[state.current_batch_index].command = c;
-					state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_NINEPATCH;
+					state.canvas_instance_batches[state.current_batch_index].specialization &= specialization_command_mask;
+					state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_NINEPATCH;
 				}
 
 				_prepare_canvas_texture(np->texture, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
@@ -1092,7 +1095,8 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 				state.canvas_instance_batches[state.current_batch_index].tex = polygon->texture;
 				state.canvas_instance_batches[state.current_batch_index].command_type = Item::Command::TYPE_POLYGON;
 				state.canvas_instance_batches[state.current_batch_index].command = c;
-				state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_ATTRIBUTES;
+				state.canvas_instance_batches[state.current_batch_index].specialization &= specialization_command_mask;
+				state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_ATTRIBUTES;
 
 				_prepare_canvas_texture(polygon->texture, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
 
@@ -1119,7 +1123,8 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 					state.canvas_instance_batches[state.current_batch_index].primitive_points = primitive->point_count;
 					state.canvas_instance_batches[state.current_batch_index].command_type = Item::Command::TYPE_PRIMITIVE;
 					state.canvas_instance_batches[state.current_batch_index].command = c;
-					state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_PRIMITIVE;
+					state.canvas_instance_batches[state.current_batch_index].specialization &= specialization_command_mask;
+					state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_PRIMITIVE;
 				}
 
 				_prepare_canvas_texture(state.canvas_instance_batches[state.current_batch_index].tex, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
@@ -1164,7 +1169,8 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 				_new_batch(r_batch_broken);
 
 				Color modulate(1, 1, 1, 1);
-				state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_ATTRIBUTES;
+				state.canvas_instance_batches[state.current_batch_index].specialization &= specialization_command_mask;
+				state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_ATTRIBUTES;
 				if (c->type == Item::Command::TYPE_MESH) {
 					const Item::CommandMesh *m = static_cast<const Item::CommandMesh *>(c);
 					state.canvas_instance_batches[state.current_batch_index].tex = m->texture;
@@ -1174,7 +1180,7 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 				} else if (c->type == Item::Command::TYPE_MULTIMESH) {
 					const Item::CommandMultiMesh *mm = static_cast<const Item::CommandMultiMesh *>(c);
 					state.canvas_instance_batches[state.current_batch_index].tex = mm->texture;
-					state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_INSTANCED;
+					state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_INSTANCING;
 
 					if (GLES3::MeshStorage::get_singleton()->multimesh_uses_colors(mm->multimesh)) {
 						state.instance_data_array[r_index].flags |= FLAGS_INSTANCING_HAS_COLORS;
@@ -1189,7 +1195,7 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 					const Item::CommandParticles *pt = static_cast<const Item::CommandParticles *>(c);
 					RID particles = pt->particles;
 					state.canvas_instance_batches[state.current_batch_index].tex = pt->texture;
-					state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_INSTANCED;
+					state.canvas_instance_batches[state.current_batch_index].specialization |= CanvasShaderGLES3::USE_INSTANCING;
 					state.instance_data_array[r_index].flags |= FLAGS_INSTANCING_HAS_COLORS;
 					state.instance_data_array[r_index].flags |= FLAGS_INSTANCING_HAS_CUSTOM_DATA;
 

drivers/gles3/rasterizer_canvas_gles3.h

@@ -273,14 +273,12 @@ public:
 
 		RID material;
 		GLES3::CanvasMaterialData *material_data = nullptr;
-		CanvasShaderGLES3::ShaderVariant shader_variant = CanvasShaderGLES3::MODE_QUAD;
 		uint64_t vertex_input_mask = RS::ARRAY_FORMAT_VERTEX | RS::ARRAY_FORMAT_COLOR | RS::ARRAY_FORMAT_TEX_UV;
+		uint64_t specialization = 0;
 
 		const Item::Command *command = nullptr;
 		Item::Command::Type command_type = Item::Command::TYPE_ANIMATION_SLICE; // Can default to any type that doesn't form a batch.
 		uint32_t primitive_points = 0;
-
-		bool lights_disabled = false;
 	};
 
 	// DataBuffer contains our per-frame data. I.e. the resources that are updated each frame.

drivers/gles3/shaders/canvas.glsl

@@ -1,17 +1,16 @@
 /* clang-format off */
 #[modes]
 
-mode_quad =
-mode_ninepatch = #define USE_NINEPATCH
-mode_primitive = #define USE_PRIMITIVE
-mode_attributes = #define USE_ATTRIBUTES
-mode_instanced = #define USE_ATTRIBUTES \n#define USE_INSTANCING
+mode_default =
 
 #[specializations]
 
 DISABLE_LIGHTING = true
 USE_RGBA_SHADOWS = false
-SINGLE_INSTANCE = false
+USE_NINEPATCH = false
+USE_PRIMITIVE = false
+USE_ATTRIBUTES = false
+USE_INSTANCING = false
 
 #[vertex]
 

drivers/gles3/shaders/sky.glsl

@@ -2,17 +2,15 @@
 #[modes]
 
 mode_background =
-mode_half_res = #define USE_HALF_RES_PASS
-mode_quarter_res = #define USE_QUARTER_RES_PASS
 mode_cubemap = #define USE_CUBEMAP_PASS
-mode_cubemap_half_res = #define USE_CUBEMAP_PASS \n#define USE_HALF_RES_PASS
-mode_cubemap_quarter_res = #define USE_CUBEMAP_PASS \n#define USE_QUARTER_RES_PASS
 
 #[specializations]
 
 USE_MULTIVIEW = false
 USE_INVERTED_Y = true
 APPLY_TONEMAPPING = true
+USE_QUARTER_RES_PASS = false
+USE_HALF_RES_PASS = false
 
 #[vertex]