Use MSDF instead of MTSDF for font rendering.

Co-authored-by: K. S. Ernest (iFire) Lee <[email protected]>

Author: bruvzg

drivers/gles3/shaders/canvas.glsl

@@ -559,8 +559,8 @@ float map_ninepatch_axis(float pixel, float draw_size, float tex_pixel_size, flo
 
 #endif
 
-float msdf_median(float r, float g, float b, float a) {
-	return min(max(min(r, g), min(max(r, g), b)), a);
+float msdf_median(float r, float g, float b) {
+	return max(min(r, g), min(max(r, g), b));
 }
 
 void main() {
@@ -606,14 +606,15 @@ void main() {
 		vec2 msdf_size = vec2(textureSize(color_texture, 0));
 		vec2 dest_size = vec2(1.0) / fwidth(uv);
 		float px_size = max(0.5 * dot((vec2(px_range) / msdf_size), dest_size), 1.0);
-		float d = msdf_median(msdf_sample.r, msdf_sample.g, msdf_sample.b, msdf_sample.a) - 0.5;
+		float d = msdf_median(msdf_sample.r, msdf_sample.g, msdf_sample.b);
 
 		if (outline_thickness > 0.0) {
 			float cr = clamp(outline_thickness, 0.0, px_range / 2.0) / px_range;
-			float a = clamp((d + cr) * px_size, 0.0, 1.0);
+			d = min(d, msdf_sample.a);
+			float a = clamp((d - 0.5 + cr) * px_size + 0.5, 0.0, 1.0);
 			color.a = a * color.a;
 		} else {
-			float a = clamp(d * px_size + 0.5, 0.0, 1.0);
+			float a = clamp((d - 0.5) * px_size + 0.5, 0.0, 1.0);
 			color.a = a * color.a;
 		}
 	} else if (bool(read_draw_data_flags & INSTANCE_FLAGS_USE_LCD)) {

modules/text_server_adv/text_server_adv.cpp

@@ -881,9 +881,15 @@ _FORCE_INLINE_ TextServerAdvanced::FontTexturePosition TextServerAdvanced::find_
 				}
 			} else if (p_color_size == 4) {
 				for (int i = 0; i < texsize * texsize * p_color_size; i += 4) { // FORMAT_RGBA8, Color font, Multichannel(+True) SDF.
-					w[i + 0] = 255;
-					w[i + 1] = 255;
-					w[i + 2] = 255;
+					if (p_msdf) {
+						w[i + 0] = 0;
+						w[i + 1] = 0;
+						w[i + 2] = 0;
+					} else {
+						w[i + 0] = 255;
+						w[i + 1] = 255;
+						w[i + 2] = 255;
+					}
 					w[i + 3] = 0;
 				}
 			} else {

modules/text_server_fb/text_server_fb.cpp

@@ -304,9 +304,15 @@ _FORCE_INLINE_ TextServerFallback::FontTexturePosition TextServerFallback::find_
 				}
 			} else if (p_color_size == 4) {
 				for (int i = 0; i < texsize * texsize * p_color_size; i += 4) { // FORMAT_RGBA8, Color font, Multichannel(+True) SDF.
-					w[i + 0] = 255;
-					w[i + 1] = 255;
-					w[i + 2] = 255;
+					if (p_msdf) {
+						w[i + 0] = 0;
+						w[i + 1] = 0;
+						w[i + 2] = 0;
+					} else {
+						w[i + 0] = 255;
+						w[i + 1] = 255;
+						w[i + 2] = 255;
+					}
 					w[i + 3] = 0;
 				}
 			} else {

scene/resources/material.cpp

@@ -1476,8 +1476,8 @@ void vertex() {)";
 
 	if (flags[FLAG_ALBEDO_TEXTURE_MSDF] && !flags[FLAG_UV1_USE_TRIPLANAR]) {
 		code += R"(
-float msdf_median(float r, float g, float b, float a) {
-	return min(max(min(r, g), min(max(r, g), b)), a);
+float msdf_median(float r, float g, float b) {
+	return max(min(r, g), min(max(r, g), b));
 }
 )";
 	}
@@ -1621,10 +1621,12 @@ void fragment() {)";
 		code += R"(
 	{
 		// Albedo Texture MSDF: Enabled
-		albedo_tex.rgb = mix(
-				vec3(1.0 + 0.055) * pow(albedo_tex.rgb, vec3(1.0 / 2.4)) - vec3(0.055),
-				vec3(12.92) * albedo_tex.rgb,
-				lessThan(albedo_tex.rgb, vec3(0.0031308)));
+		if (!OUTPUT_IS_SRGB) {
+			albedo_tex.rgb = mix(
+					vec3(1.0 + 0.055) * pow(albedo_tex.rgb, vec3(1.0 / 2.4)) - vec3(0.055),
+					vec3(12.92) * albedo_tex.rgb,
+					lessThan(albedo_tex.rgb, vec3(0.0031308)));
+		}
 		vec2 msdf_size = vec2(msdf_pixel_range) / vec2(albedo_texture_size);
 )";
 		if (flags[FLAG_USE_POINT_SIZE]) {
@@ -1634,12 +1636,13 @@ void fragment() {)";
 		}
 		code += R"(
 		float px_size = max(0.5 * dot(msdf_size, dest_size), 1.0);
-		float d = msdf_median(albedo_tex.r, albedo_tex.g, albedo_tex.b, albedo_tex.a) - 0.5;
+		float d = msdf_median(albedo_tex.r, albedo_tex.g, albedo_tex.b);
 		if (msdf_outline_size > 0.0) {
 			float cr = clamp(msdf_outline_size, 0.0, msdf_pixel_range / 2.0) / msdf_pixel_range;
-			albedo_tex.a = clamp((d + cr) * px_size, 0.0, 1.0);
+			d = min(d, albedo_tex.a);
+			albedo_tex.a = clamp((d - 0.5 + cr) * px_size + 0.5, 0.0, 1.0);
 		} else {
-			albedo_tex.a = clamp(d * px_size + 0.5, 0.0, 1.0);
+			albedo_tex.a = clamp((d - 0.5) * px_size + 0.5, 0.0, 1.0);
 		}
 		albedo_tex.rgb = vec3(1.0);
 	}

servers/rendering/renderer_rd/shaders/canvas.glsl

@@ -462,8 +462,8 @@ void light_blend_compute(uint light_base, vec4 light_color, inout vec3 color) {
 	}
 }
 
-float msdf_median(float r, float g, float b, float a) {
-	return min(max(min(r, g), min(max(r, g), b)), a);
+float msdf_median(float r, float g, float b) {
+	return max(min(r, g), min(max(r, g), b));
 }
 
 void main() {
@@ -513,14 +513,15 @@ void main() {
 		vec2 msdf_size = vec2(textureSize(sampler2D(color_texture, texture_sampler), 0));
 		vec2 dest_size = vec2(1.0) / fwidth(uv);
 		float px_size = max(0.5 * dot((vec2(px_range) / msdf_size), dest_size), 1.0);
-		float d = msdf_median(msdf_sample.r, msdf_sample.g, msdf_sample.b, msdf_sample.a) - 0.5;
+		float d = msdf_median(msdf_sample.r, msdf_sample.g, msdf_sample.b);
 
 		if (outline_thickness > 0) {
 			float cr = clamp(outline_thickness, 0.0, px_range / 2) / px_range;
-			float a = clamp((d + cr) * px_size, 0.0, 1.0);
+			d = min(d, msdf_sample.a);
+			float a = clamp((d - 0.5 + cr) * px_size + 0.5, 0.0, 1.0);
 			color.a = a * color.a;
 		} else {
-			float a = clamp(d * px_size + 0.5, 0.0, 1.0);
+			float a = clamp((d - 0.5) * px_size + 0.5, 0.0, 1.0);
 			color.a = a * color.a;
 		}
 	} else if (bool(draw_data.flags & INSTANCE_FLAGS_USE_LCD)) {