Add antialiasing filters (FXAA, SSAA) (luanti-org#13253)

builtin/settingtypes.txt

@@ -342,14 +342,27 @@ texture_clean_transparent (Clean transparent textures) bool false
 #    texture autoscaling.
 texture_min_size (Minimum texture size) int 64 1 32768
 
-#    Use multi-sample antialiasing (MSAA) to smooth out block edges.
-#    This algorithm smooths out the 3D viewport while keeping the image sharp,
-#    but it doesn't affect the insides of textures
-#    (which is especially noticeable with transparent textures).
-#    Visible spaces appear between nodes when shaders are disabled.
-#    If set to 0, MSAA is disabled.
-#    A restart is required after changing this option.
-fsaa (FSAA) enum 0 0,1,2,4,8,16
+#    Select the antialiasing method to apply.
+#
+#    * None - No antialiasing (default)
+#
+#    * FSAA - Hardware-provided full-screen antialiasing (incompatible with shaders)
+#             A.K.A multi-sample antialiasing (MSAA)
+#             Smoothens out block edges but does not affect the insides of textures.
+#             A restart is required to change this option.
+#
+#    * FXAA - Fast approximate antialiasing (requires shaders)
+#             Applies a post-processing filter to detect and smoothen high-contrast edges.
+#             Provides balance between speed and image quality.
+#
+#    * SSAA - Super-sampling antialiasing (requires shaders)
+#             Renders higher-resolution image of the scene, then scales down to reduce
+#             the aliasing effects. This is the slowest and the most accurate method.
+antialiasing (Antialiasing method) enum none none,fsaa,fxaa,ssaa
+
+#    Defines size of the sampling grid for FSAA and SSAA antializasing methods.
+#    Value of 2 means taking 2x2 = 4 samples.
+fsaa (Anti-aliasing scale) enum 2 2,4,8,16
 
 [**Occlusion Culling]
 

client/shaders/fxaa/opengl_fragment.glsl

@@ -0,0 +1,116 @@
+#define rendered texture0
+
+uniform sampler2D rendered;
+uniform vec2 texelSize0;
+
+varying vec2 sampleNW;
+varying vec2 sampleNE;
+varying vec2 sampleSW;
+varying vec2 sampleSE;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+/**
+Basic FXAA implementation based on the code on geeks3d.com with the
+modification that the texture2DLod stuff was removed since it's
+unsupported by WebGL.
+--
+From:
+https://github.com/mitsuhiko/webgl-meincraft
+Copyright (c) 2011 by Armin Ronacher.
+Some rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * The names of the contributors may not be used to endorse or
+      promote products derived from this software without specific
+      prior written permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef FXAA_REDUCE_MIN
+    #define FXAA_REDUCE_MIN   (1.0/ 128.0)
+#endif
+#ifndef FXAA_REDUCE_MUL
+    #define FXAA_REDUCE_MUL   (1.0 / 8.0)
+#endif
+#ifndef FXAA_SPAN_MAX
+    #define FXAA_SPAN_MAX     8.0
+#endif
+
+//optimized version for mobile, where dependent 
+//texture reads can be a bottleneck
+vec4 fxaa(sampler2D tex, vec2 fragCoord, vec2 inverseVP,
+            vec2 v_rgbNW, vec2 v_rgbNE, 
+            vec2 v_rgbSW, vec2 v_rgbSE, 
+            vec2 v_rgbM) {
+    vec4 color;
+    vec3 rgbNW = texture2D(tex, v_rgbNW).xyz;
+    vec3 rgbNE = texture2D(tex, v_rgbNE).xyz;
+    vec3 rgbSW = texture2D(tex, v_rgbSW).xyz;
+    vec3 rgbSE = texture2D(tex, v_rgbSE).xyz;
+    vec4 texColor = texture2D(tex, v_rgbM);
+    vec3 rgbM  = texColor.xyz;
+    vec3 luma = vec3(0.299, 0.587, 0.114);
+    float lumaNW = dot(rgbNW, luma);
+    float lumaNE = dot(rgbNE, luma);
+    float lumaSW = dot(rgbSW, luma);
+    float lumaSE = dot(rgbSE, luma);
+    float lumaM  = dot(rgbM,  luma);
+    float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
+    float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
+
+    mediump vec2 dir;
+    dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
+    dir.y =  ((lumaNW + lumaSW) - (lumaNE + lumaSE));
+
+    float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) *
+                          (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
+
+    float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
+    dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
+              max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
+              dir * rcpDirMin)) * inverseVP;
+
+    vec3 rgbA = 0.5 * (
+        texture2D(tex, fragCoord + dir * (1.0 / 3.0 - 0.5)).xyz +
+        texture2D(tex, fragCoord + dir * (2.0 / 3.0 - 0.5)).xyz);
+    vec3 rgbB = rgbA * 0.5 + 0.25 * (
+        texture2D(tex, fragCoord + dir * -0.5).xyz +
+        texture2D(tex, fragCoord + dir * 0.5).xyz);
+
+    float lumaB = dot(rgbB, luma);
+    if ((lumaB < lumaMin) || (lumaB > lumaMax))
+        color = vec4(rgbA, 1.0);
+    else
+        color = vec4(rgbB, 1.0);
+    return color;
+}
+
+void main(void)
+{
+	vec2 uv = varTexCoord.st;
+
+	gl_FragColor = fxaa(rendered, uv, texelSize0, 
+		sampleNW, sampleNE, sampleSW, sampleSE, uv);
+}

client/shaders/fxaa/opengl_vertex.glsl

@@ -0,0 +1,27 @@
+uniform vec2 texelSize0;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+varying vec2 sampleNW;
+varying vec2 sampleNE;
+varying vec2 sampleSW;
+varying vec2 sampleSE;
+
+/*
+Based on 
+https://github.com/mattdesl/glsl-fxaa/
+Portions Copyright (c) 2011 by Armin Ronacher.
+*/
+void main(void)
+{
+	varTexCoord.st = inTexCoord0.st;
+	sampleNW = varTexCoord.st + vec2(-1.0, -1.0) * texelSize0;
+	sampleNE = varTexCoord.st + vec2(1.0, -1.0) * texelSize0;
+	sampleSW = varTexCoord.st + vec2(-1.0, 1.0) * texelSize0;
+	sampleSE = varTexCoord.st + vec2(1.0, 1.0) * texelSize0;
+	gl_Position = inVertexPosition;
+}

client/shaders/second_stage/opengl_fragment.glsl

@@ -8,6 +8,8 @@ struct ExposureParams {
 uniform sampler2D rendered;
 uniform sampler2D bloom;
 
+uniform vec2 texelSize0;
+
 uniform ExposureParams exposureParams;
 uniform lowp float bloomIntensity;
 uniform lowp float saturation;
@@ -80,7 +82,15 @@ vec3 applySaturation(vec3 color, float factor)
 void main(void)
 {
 	vec2 uv = varTexCoord.st;
+#ifdef ENABLE_SSAA
+	vec4 color = vec4(0.);
+	for (float dx = 1.; dx < SSAA_SCALE; dx += 2.)
+	for (float dy = 1.; dy < SSAA_SCALE; dy += 2.)
+		color += texture2D(rendered, uv + texelSize0 * vec2(dx, dy)).rgba;
+	color /= SSAA_SCALE * SSAA_SCALE / 4.;
+#else
 	vec4 color = texture2D(rendered, uv).rgba;
+#endif
 
 	// translate to linear colorspace (approximate)
 	color.rgb = pow(color.rgb, vec3(2.2));

src/client/game.cpp

@@ -387,7 +387,8 @@ class GameGlobalShaderConstantSetter : public IShaderConstantSetter
 	CachedPixelShaderSetting<SamplerLayer_t> m_texture1;
 	CachedPixelShaderSetting<SamplerLayer_t> m_texture2;
 	CachedPixelShaderSetting<SamplerLayer_t> m_texture3;
-	CachedPixelShaderSetting<float, 2> m_texel_size0;
+	CachedVertexShaderSetting<float, 2> m_texel_size0_vertex;
+	CachedPixelShaderSetting<float, 2> m_texel_size0_pixel;
 	std::array<float, 2> m_texel_size0_values;
 	CachedStructPixelShaderSetting<float, 7> m_exposure_params_pixel;
 	float m_user_exposure_compensation;
@@ -445,7 +446,8 @@ class GameGlobalShaderConstantSetter : public IShaderConstantSetter
 		m_texture1("texture1"),
 		m_texture2("texture2"),
 		m_texture3("texture3"),
-		m_texel_size0("texelSize0"),
+		m_texel_size0_vertex("texelSize0"),
+		m_texel_size0_pixel("texelSize0"),
 		m_exposure_params_pixel("exposureParams",
 				std::array<const char*, 7> {
 						"luminanceMin", "luminanceMax", "exposureCorrection",
@@ -547,7 +549,8 @@ class GameGlobalShaderConstantSetter : public IShaderConstantSetter
 		tex_id = 3;
 		m_texture3.set(&tex_id, services);
 
-		m_texel_size0.set(m_texel_size0_values.data(), services);
+		m_texel_size0_vertex.set(m_texel_size0_values.data(), services);
+		m_texel_size0_pixel.set(m_texel_size0_values.data(), services);
 
 		const AutoExposure &exposure_params = m_client->getEnv().getLocalPlayer()->getLighting().exposure;
 		std::array<float, 7> exposure_buffer = {

src/client/render/plain.cpp

@@ -130,6 +130,11 @@ RenderStep* addUpscaling(RenderPipeline *pipeline, RenderStep *previousStep, v2f
 	if (downscale_factor.X == 1.0f && downscale_factor.Y == 1.0f)
 		return previousStep;
 
+	// When shaders are enabled, post-processing pipeline takes care of rescaling
+	if (g_settings->getBool("enable_shaders"))
+		return previousStep;
+
+
 	// Initialize buffer
 	TextureBuffer *buffer = pipeline->createOwned<TextureBuffer>();
 	buffer->setTexture(TEXTURE_UPSCALE, downscale_factor, "upscale", video::ECF_A8R8G8B8);

src/client/render/secondstage.cpp

@@ -118,9 +118,23 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
 	static const u8 TEXTURE_BLOOM = 2;
 	static const u8 TEXTURE_EXPOSURE_1 = 3;
 	static const u8 TEXTURE_EXPOSURE_2 = 4;
+	static const u8 TEXTURE_FXAA = 5;
 	static const u8 TEXTURE_BLOOM_DOWN = 10;
 	static const u8 TEXTURE_BLOOM_UP = 20;
 
+	// Super-sampling is simply rendering into a larger texture.
+	// Downscaling is done by the final step when rendering to the screen.
+	const std::string antialiasing = g_settings->get("antialiasing");
+	const bool enable_bloom = g_settings->getBool("enable_bloom");
+	const bool enable_auto_exposure = g_settings->getBool("enable_auto_exposure");
+	const bool enable_ssaa = antialiasing == "ssaa";
+	const bool enable_fxaa = antialiasing == "fxaa";
+
+	if (enable_ssaa) {
+		u16 ssaa_scale = MYMAX(2, g_settings->getU16("fsaa"));
+		scale *= ssaa_scale;
+	}
+
 	buffer->setTexture(TEXTURE_COLOR, scale, "3d_render", color_format);
 	buffer->setTexture(TEXTURE_EXPOSURE_1, core::dimension2du(1,1), "exposure_1", color_format, /*clear:*/ true);
 	buffer->setTexture(TEXTURE_EXPOSURE_2, core::dimension2du(1,1), "exposure_2", color_format, /*clear:*/ true);
@@ -135,8 +149,6 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
 	// Number of mipmap levels of the bloom downsampling texture
 	const u8 MIPMAP_LEVELS = 4;
 
-	const bool enable_bloom = g_settings->getBool("enable_bloom");
-	const bool enable_auto_exposure = g_settings->getBool("enable_auto_exposure");
 
 	// post-processing stage
 
@@ -175,6 +187,7 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
 		}
 	}
 
+	// Bloom pt 2
 	if (enable_bloom) {
 		// upsample
 		shader_id = client->getShaderSource()->getShader("bloom_upsample", TILE_MATERIAL_PLAIN, NDT_MESH);
@@ -188,6 +201,7 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
 		}
 	}
 
+	// Dynamic Exposure pt2
 	if (enable_auto_exposure) {
 		shader_id = client->getShaderSource()->getShader("update_exposure", TILE_MATERIAL_PLAIN, NDT_MESH);
 		auto update_exposure = pipeline->addStep<PostProcessingStep>(shader_id, std::vector<u8> { TEXTURE_EXPOSURE_1, u8(TEXTURE_BLOOM_DOWN + MIPMAP_LEVELS - 1) });
@@ -196,11 +210,28 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
 		update_exposure->setRenderTarget(pipeline->createOwned<TextureBufferOutput>(buffer, TEXTURE_EXPOSURE_2));
 	}
 
-	// final post-processing
+	// FXAA
+	u8 final_stage_source = TEXTURE_COLOR;
+
+	if (enable_fxaa) {
+		final_stage_source = TEXTURE_FXAA;
+
+		buffer->setTexture(TEXTURE_FXAA, scale, "fxaa", color_format);
+		shader_id = client->getShaderSource()->getShader("fxaa", TILE_MATERIAL_PLAIN);
+		PostProcessingStep *effect = pipeline->createOwned<PostProcessingStep>(shader_id, std::vector<u8> { TEXTURE_COLOR });
+		pipeline->addStep(effect);
+		effect->setBilinearFilter(0, true);
+		effect->setRenderSource(buffer);
+		effect->setRenderTarget(pipeline->createOwned<TextureBufferOutput>(buffer, TEXTURE_FXAA));
+	}
+
+	// final merge
 	shader_id = client->getShaderSource()->getShader("second_stage", TILE_MATERIAL_PLAIN, NDT_MESH);
-	PostProcessingStep *effect = pipeline->createOwned<PostProcessingStep>(shader_id, std::vector<u8> { TEXTURE_COLOR, TEXTURE_BLOOM_UP, TEXTURE_EXPOSURE_2 });
+	PostProcessingStep *effect = pipeline->createOwned<PostProcessingStep>(shader_id, std::vector<u8> { final_stage_source, TEXTURE_BLOOM_UP, TEXTURE_EXPOSURE_2 });
 	pipeline->addStep(effect);
-	effect->setBilinearFilter(1, true); // apply filter to the bloom
+	if (enable_ssaa)
+		effect->setBilinearFilter(0, true);
+	effect->setBilinearFilter(1, true);
 	effect->setRenderSource(buffer);
 
 	if (enable_auto_exposure) {

src/client/renderingengine.cpp

@@ -122,7 +122,8 @@ RenderingEngine::RenderingEngine(IEventReceiver *receiver)
 
 	// bpp, fsaa, vsync
 	bool vsync = g_settings->getBool("vsync");
-	u16 fsaa = g_settings->getU16("fsaa");
+	bool enable_fsaa = g_settings->get("antialiasing") == "fsaa";
+	u16 fsaa = enable_fsaa ? g_settings->getU16("fsaa") : 0;
 
 	// Determine driver
 	auto driverType = chooseVideoDriver();

src/client/shader.cpp

@@ -780,6 +780,12 @@ ShaderInfo ShaderSource::generateShader(const std::string &name,
 	if (g_settings->getBool("enable_auto_exposure"))
 		shaders_header << "#define ENABLE_AUTO_EXPOSURE 1\n";
 
+	if (g_settings->get("antialiasing") == "ssaa") {
+		shaders_header << "#define ENABLE_SSAA 1\n";
+		u16 ssaa_scale = MYMAX(2, g_settings->getU16("fsaa"));
+		shaders_header << "#define SSAA_SCALE " << ssaa_scale << ".\n";
+	}
+
 	shaders_header << "#line 0\n"; // reset the line counter for meaningful diagnostics
 
 	std::string common_header = shaders_header.str();

src/defaultsettings.cpp

@@ -264,6 +264,7 @@ void set_default_settings()
 	settings->setDefault("enable_waving_plants", "false");
 	settings->setDefault("exposure_compensation", "0.0");
 	settings->setDefault("enable_auto_exposure", "false");
+	settings->setDefault("antialiasing", "none");
 	settings->setDefault("enable_bloom", "false");
 	settings->setDefault("enable_bloom_debug", "false");
 	settings->setDefault("bloom_strength_factor", "1.0");