Add font LCD sub-pixel anti-aliasing support.

7 files changed, 111 insertions, 64 deletions

diff --git a/drivers/gles3/rasterizer_canvas_gles3.cpp b/drivers/gles3/rasterizer_canvas_gles3.cpp
index 28802f571c..b397d0c665 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.cpp
+++ b/drivers/gles3/rasterizer_canvas_gles3.cpp
@@ -322,6 +322,7 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 	RID prev_material;
 	uint32_t index = 0;
 	GLES3::CanvasShaderData::BlendMode last_blend_mode = GLES3::CanvasShaderData::BLEND_MODE_MIX;
+	Color last_blend_color;
 	GLES3::CanvasShaderData *shader_data_cache = nullptr;
 
 	state.current_tex = texture_storage->texture_gl_get_default(GLES3::DEFAULT_GL_TEXTURE_WHITE);
@@ -378,8 +379,80 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 
 		GLES3::CanvasShaderData::BlendMode blend_mode = shader_data_cache ? shader_data_cache->blend_mode : GLES3::CanvasShaderData::BLEND_MODE_MIX;
 
-		if (last_blend_mode != blend_mode) {
-			if (last_blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
+		_render_item(p_to_render_target, ci, canvas_transform_inverse, current_clip, p_lights, index, blend_mode, last_blend_mode, last_blend_color);
+	}
+	// Render last command
+	_render_batch(index);
+}
+
+void RasterizerCanvasGLES3::_render_item(RID p_render_target, const Item *p_item, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, Light *p_lights, uint32_t &r_index, GLES3::CanvasShaderData::BlendMode p_blend_mode, GLES3::CanvasShaderData::BlendMode &r_last_blend_mode, Color &r_last_blend_color) {
+	// Used by Polygon and Mesh.
+	static const GLenum prim[5] = { GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_TRIANGLES, GL_TRIANGLE_STRIP };
+
+	RS::CanvasItemTextureFilter current_filter = state.default_filter;
+	RS::CanvasItemTextureRepeat current_repeat = state.default_repeat;
+
+	if (p_item->texture_filter != RS::CANVAS_ITEM_TEXTURE_FILTER_DEFAULT) {
+		current_filter = p_item->texture_filter;
+	}
+
+	if (p_item->texture_repeat != RS::CANVAS_ITEM_TEXTURE_REPEAT_DEFAULT) {
+		current_repeat = p_item->texture_repeat;
+	}
+
+	Transform2D base_transform = p_canvas_transform_inverse * p_item->final_transform;
+	Transform2D draw_transform; // Used by transform command
+
+	Color base_color = p_item->final_modulate;
+
+	uint32_t base_flags = 0;
+
+	bool reclip = false;
+
+	bool skipping = false;
+
+	const Item::Command *c = p_item->commands;
+	while (c) {
+		if (skipping && c->type != Item::Command::TYPE_ANIMATION_SLICE) {
+			c = c->next;
+			continue;
+		}
+
+		if (c->type != Item::Command::TYPE_MESH) {
+			// For Meshes, this gets updated below.
+			_update_transform_2d_to_mat2x3(base_transform * draw_transform, state.instance_data_array[r_index].world);
+		}
+
+		for (int i = 0; i < 4; i++) {
+			state.instance_data_array[r_index].modulation[i] = 0.0;
+			state.instance_data_array[r_index].ninepatch_margins[i] = 0.0;
+			state.instance_data_array[r_index].src_rect[i] = 0.0;
+			state.instance_data_array[r_index].dst_rect[i] = 0.0;
+			state.instance_data_array[r_index].lights[i] = uint32_t(0);
+		}
+		state.instance_data_array[r_index].color_texture_pixel_size[0] = 0.0;
+		state.instance_data_array[r_index].color_texture_pixel_size[1] = 0.0;
+
+		state.instance_data_array[r_index].pad[0] = 0.0;
+		state.instance_data_array[r_index].pad[1] = 0.0;
+
+		state.instance_data_array[r_index].flags = base_flags | (state.instance_data_array[r_index == 0 ? 0 : r_index - 1].flags & (FLAGS_DEFAULT_NORMAL_MAP_USED | FLAGS_DEFAULT_SPECULAR_MAP_USED)); //reset on each command for sanity, keep canvastexture binding config
+
+		GLES3::CanvasShaderData::BlendMode blend_mode = p_blend_mode;
+		Color blend_color;
+
+		if (c->type == Item::Command::TYPE_RECT) {
+			const Item::CommandRect *rect = static_cast<const Item::CommandRect *>(c);
+			if (rect->flags & CANVAS_RECT_LCD) {
+				blend_mode = GLES3::CanvasShaderData::BLEND_MODE_LCD;
+				blend_color = rect->modulate;
+			}
+		}
+
+		if (r_last_blend_mode != blend_mode || r_last_blend_color != blend_color) {
+			_render_batch(r_index);
+
+			if (r_last_blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
 				// re-enable it
 				glEnable(GL_BLEND);
 			} else if (blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
@@ -392,6 +465,16 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 					// Nothing to do here.
 
 				} break;
+				case GLES3::CanvasShaderData::BLEND_MODE_LCD: {
+					glBlendEquation(GL_FUNC_ADD);
+					if (state.transparent_render_target) {
+						glBlendFuncSeparate(GL_CONSTANT_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+					} else {
+						glBlendFuncSeparate(GL_CONSTANT_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_ZERO, GL_ONE);
+					}
+					glBlendColor(blend_color.r, blend_color.g, blend_color.b, blend_color.a);
+
+				} break;
 				case GLES3::CanvasShaderData::BLEND_MODE_MIX: {
 					glBlendEquation(GL_FUNC_ADD);
 					if (state.transparent_render_target) {
@@ -437,68 +520,10 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 
 				} break;
 			}
-			last_blend_mode = blend_mode;
-		}
-
-		_render_item(p_to_render_target, ci, canvas_transform_inverse, current_clip, p_lights, index);
-	}
-	// Render last command
-	_render_batch(index);
-}
-
-void RasterizerCanvasGLES3::_render_item(RID p_render_target, const Item *p_item, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, Light *p_lights, uint32_t &r_index) {
-	// Used by Polygon and Mesh.
-	static const GLenum prim[5] = { GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_TRIANGLES, GL_TRIANGLE_STRIP };
-
-	RS::CanvasItemTextureFilter current_filter = state.default_filter;
-	RS::CanvasItemTextureRepeat current_repeat = state.default_repeat;
-
-	if (p_item->texture_filter != RS::CANVAS_ITEM_TEXTURE_FILTER_DEFAULT) {
-		current_filter = p_item->texture_filter;
-	}
-
-	if (p_item->texture_repeat != RS::CANVAS_ITEM_TEXTURE_REPEAT_DEFAULT) {
-		current_repeat = p_item->texture_repeat;
-	}
-
-	Transform2D base_transform = p_canvas_transform_inverse * p_item->final_transform;
-	Transform2D draw_transform; // Used by transform command
-
-	Color base_color = p_item->final_modulate;
-
-	uint32_t base_flags = 0;
-
-	bool reclip = false;
-
-	bool skipping = false;
-
-	const Item::Command *c = p_item->commands;
-	while (c) {
-		if (skipping && c->type != Item::Command::TYPE_ANIMATION_SLICE) {
-			c = c->next;
-			continue;
-		}
-
-		if (c->type != Item::Command::TYPE_MESH) {
-			// For Meshes, this gets updated below.
-			_update_transform_2d_to_mat2x3(base_transform * draw_transform, state.instance_data_array[r_index].world);
+			r_last_blend_mode = blend_mode;
+			r_last_blend_color = blend_color;
 		}
 
-		for (int i = 0; i < 4; i++) {
-			state.instance_data_array[r_index].modulation[i] = 0.0;
-			state.instance_data_array[r_index].ninepatch_margins[i] = 0.0;
-			state.instance_data_array[r_index].src_rect[i] = 0.0;
-			state.instance_data_array[r_index].dst_rect[i] = 0.0;
-			state.instance_data_array[r_index].lights[i] = uint32_t(0);
-		}
-		state.instance_data_array[r_index].color_texture_pixel_size[0] = 0.0;
-		state.instance_data_array[r_index].color_texture_pixel_size[1] = 0.0;
-
-		state.instance_data_array[r_index].pad[0] = 0.0;
-		state.instance_data_array[r_index].pad[1] = 0.0;
-
-		state.instance_data_array[r_index].flags = base_flags | (state.instance_data_array[r_index == 0 ? 0 : r_index - 1].flags & (FLAGS_DEFAULT_NORMAL_MAP_USED | FLAGS_DEFAULT_SPECULAR_MAP_USED)); //reset on each command for sanity, keep canvastexture binding config
-
 		switch (c->type) {
 			case Item::Command::TYPE_RECT: {
 				const Item::CommandRect *rect = static_cast<const Item::CommandRect *>(c);
@@ -569,6 +594,8 @@ void RasterizerCanvasGLES3::_render_item(RID p_render_target, const Item *p_item
 					state.instance_data_array[r_index].msdf[1] = rect->outline; // Outline size.
 					state.instance_data_array[r_index].msdf[2] = 0.f; // Reserved.
 					state.instance_data_array[r_index].msdf[3] = 0.f; // Reserved.
+				} else if (rect->flags & CANVAS_RECT_LCD) {
+					state.instance_data_array[r_index].flags |= FLAGS_USE_LCD;
 				}
 
 				state.instance_data_array[r_index].modulation[0] = rect->modulate.r * base_color.r;
diff --git a/drivers/gles3/rasterizer_canvas_gles3.h b/drivers/gles3/rasterizer_canvas_gles3.h
index f920e37130..372ac00493 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.h
+++ b/drivers/gles3/rasterizer_canvas_gles3.h
@@ -73,6 +73,7 @@ class RasterizerCanvasGLES3 : public RendererCanvasRender {
 		FLAGS_DEFAULT_SPECULAR_MAP_USED = (1 << 27),
 
 		FLAGS_USE_MSDF = (1 << 28),
+		FLAGS_USE_LCD = (1 << 29),
 	};
 
 	enum {
@@ -249,7 +250,7 @@ public:
 
 	void canvas_render_items(RID p_to_render_target, Item *p_item_list, const Color &p_modulate, Light *p_light_list, Light *p_directional_list, const Transform2D &p_canvas_transform, RS::CanvasItemTextureFilter p_default_filter, RS::CanvasItemTextureRepeat p_default_repeat, bool p_snap_2d_vertices_to_pixel, bool &r_sdf_used) override;
 	void _render_items(RID p_to_render_target, int p_item_count, const Transform2D &p_canvas_transform_inverse, Light *p_lights, bool p_to_backbuffer = false);
-	void _render_item(RID p_render_target, const Item *p_item, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, Light *p_lights, uint32_t &r_index);
+	void _render_item(RID p_render_target, const Item *p_item, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, Light *p_lights, uint32_t &r_index, GLES3::CanvasShaderData::BlendMode p_blend_mode, GLES3::CanvasShaderData::BlendMode &r_last_blend_mode, Color &r_last_blend_color);
 	void _render_batch(uint32_t &p_max_index);
 	void _bind_instance_data_buffer(uint32_t p_max_index);
 	void _allocate_instance_data_buffer();
diff --git a/drivers/gles3/shaders/canvas.glsl b/drivers/gles3/shaders/canvas.glsl
index 4df818cd4c..5ec25327be 100644
--- a/drivers/gles3/shaders/canvas.glsl
+++ b/drivers/gles3/shaders/canvas.glsl
@@ -473,7 +473,13 @@ void main() {
 			float a = clamp(d * px_size + 0.5, 0.0, 1.0);
 			color.a = a * color.a;
 		}
-
+	} else if (bool(draw_data[draw_data_instance].flags & FLAGS_USE_LCD)) {
+		vec4 lcd_sample = texture(color_texture, uv);
+		if (lcd_sample.a == 1.0) {
+			color.rgb = lcd_sample.rgb * color.a;
+		} else {
+			color = vec4(0.0, 0.0, 0.0, 0.0);
+		}
 	} else {
 #else
 	{
diff --git a/drivers/gles3/shaders/canvas_uniforms_inc.glsl b/drivers/gles3/shaders/canvas_uniforms_inc.glsl
index 852dccf415..6b61fe9375 100644
--- a/drivers/gles3/shaders/canvas_uniforms_inc.glsl
+++ b/drivers/gles3/shaders/canvas_uniforms_inc.glsl
@@ -25,6 +25,7 @@
 #define FLAGS_DEFAULT_SPECULAR_MAP_USED uint(1 << 27)
 
 #define FLAGS_USE_MSDF uint(1 << 28)
+#define FLAGS_USE_LCD uint(1 << 29)
 
 // must be always 128 bytes long
 struct DrawData {
diff --git a/drivers/gles3/storage/material_storage.h b/drivers/gles3/storage/material_storage.h
index d135357f6a..a2a7554821 100644
--- a/drivers/gles3/storage/material_storage.h
+++ b/drivers/gles3/storage/material_storage.h
@@ -142,6 +142,7 @@ struct CanvasShaderData : public ShaderData {
 		BLEND_MODE_MUL,
 		BLEND_MODE_PMALPHA,
 		BLEND_MODE_DISABLED,
+		BLEND_MODE_LCD,
 	};
 
 	bool valid;
diff --git a/drivers/vulkan/rendering_device_vulkan.cpp b/drivers/vulkan/rendering_device_vulkan.cpp
index 2debba1b83..f2d78636d7 100644
--- a/drivers/vulkan/rendering_device_vulkan.cpp
+++ b/drivers/vulkan/rendering_device_vulkan.cpp
@@ -7543,6 +7543,16 @@ RenderingDeviceVulkan::DrawList *RenderingDeviceVulkan::_get_draw_list_ptr(DrawL
 	}
 }
 
+void RenderingDeviceVulkan::draw_list_set_blend_constants(DrawListID p_list, const Color &p_color) {
+	DrawList *dl = _get_draw_list_ptr(p_list);
+	ERR_FAIL_COND(!dl);
+#ifdef DEBUG_ENABLED
+	ERR_FAIL_COND_MSG(!dl->validation.active, "Submitted Draw Lists can no longer be modified.");
+#endif
+
+	vkCmdSetBlendConstants(dl->command_buffer, p_color.components);
+}
+
 void RenderingDeviceVulkan::draw_list_bind_render_pipeline(DrawListID p_list, RID p_render_pipeline) {
 	DrawList *dl = _get_draw_list_ptr(p_list);
 	ERR_FAIL_COND(!dl);
diff --git a/drivers/vulkan/rendering_device_vulkan.h b/drivers/vulkan/rendering_device_vulkan.h
index 6572de7c52..6007e1ab4d 100644
--- a/drivers/vulkan/rendering_device_vulkan.h
+++ b/drivers/vulkan/rendering_device_vulkan.h
@@ -1155,6 +1155,7 @@ public:
 	virtual DrawListID draw_list_begin(RID p_framebuffer, InitialAction p_initial_color_action, FinalAction p_final_color_action, InitialAction p_initial_depth_action, FinalAction p_final_depth_action, const Vector<Color> &p_clear_color_values = Vector<Color>(), float p_clear_depth = 1.0, uint32_t p_clear_stencil = 0, const Rect2 &p_region = Rect2(), const Vector<RID> &p_storage_textures = Vector<RID>());
 	virtual Error draw_list_begin_split(RID p_framebuffer, uint32_t p_splits, DrawListID *r_split_ids, InitialAction p_initial_color_action, FinalAction p_final_color_action, InitialAction p_initial_depth_action, FinalAction p_final_depth_action, const Vector<Color> &p_clear_color_values = Vector<Color>(), float p_clear_depth = 1.0, uint32_t p_clear_stencil = 0, const Rect2 &p_region = Rect2(), const Vector<RID> &p_storage_textures = Vector<RID>());
 
+	virtual void draw_list_set_blend_constants(DrawListID p_list, const Color &p_color);
 	virtual void draw_list_bind_render_pipeline(DrawListID p_list, RID p_render_pipeline);
 	virtual void draw_list_bind_uniform_set(DrawListID p_list, RID p_uniform_set, uint32_t p_index);
 	virtual void draw_list_bind_vertex_array(DrawListID p_list, RID p_vertex_array);