gfx/blur/gaussian: Refactor Gaussian Blur

Gaussian Blur is another Blur that now supports the new system, increasing the maxium Blur size to 128 and adding support for Rotational and Zoom blur. Various optimizations were done to the actual shader code which further reduced the GPU usage.

Currently the Gaussian curve is recalculated when the blur is first created, which can lead to a short hitch due to it having to search for the correct kernels. This is currently unavoidable and expected behavior until a better solution is found.

Related: #45, #6

data/effects/blur/gaussian.effect

@@ -0,0 +1,146 @@
+// Parameters:
+/// OBS Default
+uniform float4x4 ViewProj;
+/// Texture
+uniform texture2d pImage;
+uniform float2 pImageTexel;
+/// Blur
+uniform float pSize;
+uniform float pAngle; 
+uniform float2 pCenter;
+uniform float2 pStepScale;
+/// Gaussian
+uniform float4 pKernel[32];
+
+#define MAX_BLUR_SIZE 128
+
+// Sampler
+sampler_state linearSampler {
+	Filter    = Linear;
+	AddressU  = Clamp;
+	AddressV  = Clamp;
+	MinLOD    = 0;
+	MaxLOD    = 0;
+};
+
+// Default Vertex Shader and Data
+struct VertDataIn {
+	float4 pos : POSITION;
+	float2 uv  : TEXCOORD0;
+};
+
+struct VertDataOut {
+	float4 pos : POSITION;
+	float2 uv  : TEXCOORD0;
+};
+
+VertDataOut VSDefault(VertDataIn vtx) {
+	VertDataOut vert_out;
+	vert_out.pos = mul(float4(vtx.pos.xyz, 1.0), ViewProj);
+	vert_out.uv  = vtx.uv;
+	return vert_out;
+}
+
+// Functions
+float GetKernelAt(int i) {
+	return ((float[4])(pKernel[floor(i/4)]))[i%4];
+}
+
+// Blur 1 Dimensional
+float4 PSBlur1D(VertDataOut vtx) : TARGET {
+	float4 final = pImage.Sample(linearSampler, vtx.uv)
+		* GetKernelAt(0);
+
+	// Loop unrolling is only possible with a fixed known maximum.
+	// Some compilers may unroll up to x iterations, but most will not.
+	for (int n = 1; n <= MAX_BLUR_SIZE; n++) {
+		float2 nstep = (pImageTexel * pStepScale) * n;
+		float kernel = GetKernelAt(n);
+		final += pImage.Sample(linearSampler, vtx.uv + nstep) * kernel;
+		final += pImage.Sample(linearSampler, vtx.uv - nstep) * kernel;
+
+		if (n >= pSize) {
+			break;
+		}
+	}
+
+	return final;
+}
+
+technique Draw {
+	pass {
+		vertex_shader = VSDefault(vtx);
+		pixel_shader  = PSBlur1D(vtx);
+	}
+}
+
+// Blur Rotation
+float2 rotate(float2 pt, float angle) {
+	float cp = cos(angle);
+	float sp = sin(angle);
+	float sn = -sp;
+	return float2((pt.x * cp) + (pt.y * sn), (pt.x * sp) + (pt.y * cp));
+}
+
+float2 rotateAround(float2 pt, float2 cpt, float angle) {
+	return rotate(pt - cpt, angle) + cpt;
+}
+
+float4 PSRotate(VertDataOut vtx) : TARGET {
+	float4 final = pImage.Sample(linearSampler, vtx.uv)
+		* GetKernelAt(0);
+	
+	float angstep = pAngle * pStepScale.x;
+
+	// Loop unrolling is only possible with a fixed known maximum.
+	// Some compilers may unroll up to x iterations, but most will not.
+	for (int n = 1; n <= MAX_BLUR_SIZE; n++) {
+		float kernel = GetKernelAt(n);
+		final += pImage.Sample(linearSampler, rotateAround(vtx.uv, pCenter, angstep * n)) * kernel;
+		final += pImage.Sample(linearSampler, rotateAround(vtx.uv, pCenter, angstep * -n)) * kernel;
+
+		if (n >= pSize) {
+			break;
+		}
+	}
+	
+	return final;
+}
+
+technique Rotate {
+	pass {
+		vertex_shader = VSDefault(vtx);
+		pixel_shader  = PSRotate(vtx);
+	}
+}
+
+// Blur Zoom
+float4 PSZoom(VertDataOut vtx) : TARGET {
+	float4 final = pImage.Sample(linearSampler, vtx.uv)
+		* GetKernelAt(0);
+
+	// step is calculated from the direction relative to the center
+	float2 dir = normalize(vtx.uv - pCenter) * pStepScale * pImageTexel;
+	float dist = distance(vtx.uv, pCenter);
+
+	// Loop unrolling is only possible with a fixed known maximum.
+	// Some compilers may unroll up to x iterations, but most will not.
+	for (int n = 1; n <= MAX_BLUR_SIZE; n++) {
+		float kernel = GetKernelAt(n);
+		final += pImage.Sample(linearSampler, vtx.uv + (dir * n) * dist) * kernel;
+		final += pImage.Sample(linearSampler, vtx.uv - (dir * n) * dist) * kernel;
+
+		if (n >= pSize) {
+			break;
+		}
+	}
+
+	return final;
+}
+
+technique Zoom {
+	pass {
+		vertex_shader = VSDefault(vtx);
+		pixel_shader  = PSZoom(vtx);
+	}
+}

source/gfx/blur/gfx-blur-gaussian.cpp

@@ -0,0 +1,577 @@
+// Modern effects for a modern Streamer
+// Copyright (C) 2019 Michael Fabian Dirks
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+#include "gfx-blur-gaussian.hpp"
+#include "plugin.hpp"
+#include "util-math.hpp"
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4201)
+#endif
+#include <obs-module.h>
+#include <obs.h>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+// FIXME: This breaks when MAX_KERNEL_SIZE is changed, due to the way the Gaussian
+//  function first goes up at the point, and then once we pass the critical point
+//  will go down again and it is not handled well. This is a pretty basic
+//  approximation anyway at the moment.
+#define MAX_KERNEL_SIZE 128
+#define MAX_BLUR_SIZE (MAX_KERNEL_SIZE - 1)
+#define SEARCH_DENSITY double_t(1. / 500.)
+#define SEARCH_THRESHOLD double_t(1. / (MAX_KERNEL_SIZE * 5))
+#define SEARCH_EXTENSION 1
+#define SEARCH_RANGE MAX_KERNEL_SIZE * 2
+
+gfx::blur::gaussian_data::gaussian_data()
+{
+	{
+		char* file = obs_module_file("effects/blur/gaussian.effect");
+		m_effect   = std::make_shared<gs::effect>(file);
+		bfree(file);
+	}
+
+	// Precalculate Kernels
+	for (size_t kernel_size = 1; kernel_size <= MAX_BLUR_SIZE; kernel_size++) {
+		std::vector<double_t> kernel_math(MAX_KERNEL_SIZE);
+		std::vector<float_t>  kernel_data(MAX_KERNEL_SIZE);
+		double_t              actual_width = 1.;
+
+		// Find actual kernel width.
+		for (double_t h = SEARCH_DENSITY; h < SEARCH_RANGE; h += SEARCH_DENSITY) {
+			if (util::math::gaussian<double_t>(double_t(kernel_size + SEARCH_EXTENSION), h) > SEARCH_THRESHOLD) {
+				actual_width = h;
+				break;
+			}
+		}
+
+		// Calculate and normalize
+		double_t sum = 0;
+		for (size_t p = 0; p <= kernel_size; p++) {
+			kernel_math[p] = util::math::gaussian<double_t>(double_t(p), actual_width);
+			sum += kernel_math[p] * (p > 0 ? 2 : 1);
+		}
+
+		// Normalize to fill the entire 0..1 range over the width.
+		double_t inverse_sum = 1.0 / sum;
+		for (size_t p = 0; p <= kernel_size; p++) {
+			kernel_data.at(p) = float_t(kernel_math[p] * inverse_sum);
+		}
+
+		m_kernels.push_back(std::move(kernel_data));
+	}
+}
+
+gfx::blur::gaussian_data::~gaussian_data()
+{
+	m_effect.reset();
+}
+
+std::shared_ptr<::gs::effect> gfx::blur::gaussian_data::get_effect()
+{
+	return m_effect;
+}
+
+std::vector<float_t> const& gfx::blur::gaussian_data::get_kernel(size_t width)
+{
+	if (width < 1)
+		width = 1;
+	if (width > MAX_BLUR_SIZE)
+		width = MAX_BLUR_SIZE;
+	width -= 1;
+	return m_kernels[width];
+}
+
+gfx::blur::gaussian_factory::gaussian_factory() {}
+
+gfx::blur::gaussian_factory::~gaussian_factory() {}
+
+bool gfx::blur::gaussian_factory::is_type_supported(::gfx::blur::type v)
+{
+	switch (v) {
+	case ::gfx::blur::type::Area:
+		return true;
+	case ::gfx::blur::type::Directional:
+		return true;
+	case ::gfx::blur::type::Rotational:
+		return true;
+	case ::gfx::blur::type::Zoom:
+		return true;
+	default:
+		return false;
+	}
+}
+
+std::shared_ptr<::gfx::blur::ibase> gfx::blur::gaussian_factory::create(::gfx::blur::type v)
+{
+	switch (v) {
+	case ::gfx::blur::type::Area:
+		return std::make_shared<::gfx::blur::gaussian>();
+	case ::gfx::blur::type::Directional:
+		return std::static_pointer_cast<::gfx::blur::gaussian>(std::make_shared<::gfx::blur::gaussian_directional>());
+	case ::gfx::blur::type::Rotational:
+		return std::make_shared<::gfx::blur::gaussian_rotational>();
+	case ::gfx::blur::type::Zoom:
+		return std::make_shared<::gfx::blur::gaussian_zoom>();
+	default:
+		throw std::runtime_error("Invalid type.");
+	}
+}
+
+double_t gfx::blur::gaussian_factory::get_min_size(::gfx::blur::type)
+{
+	return double_t(1.0);
+}
+
+double_t gfx::blur::gaussian_factory::get_step_size(::gfx::blur::type)
+{
+	return double_t(1.0);
+}
+
+double_t gfx::blur::gaussian_factory::get_max_size(::gfx::blur::type)
+{
+	return double_t(MAX_BLUR_SIZE);
+}
+
+double_t gfx::blur::gaussian_factory::get_min_angle(::gfx::blur::type v)
+{
+	switch (v) {
+	case ::gfx::blur::type::Directional:
+	case ::gfx::blur::type::Rotational:
+		return -180.0;
+	default:
+		return 0;
+	}
+}
+
+double_t gfx::blur::gaussian_factory::get_step_angle(::gfx::blur::type)
+{
+	return double_t(0.01);
+}
+
+double_t gfx::blur::gaussian_factory::get_max_angle(::gfx::blur::type v)
+{
+	switch (v) {
+	case ::gfx::blur::type::Directional:
+	case ::gfx::blur::type::Rotational:
+		return 180.0;
+	default:
+		return 0;
+	}
+}
+
+bool gfx::blur::gaussian_factory::is_step_scale_supported(::gfx::blur::type v)
+{
+	switch (v) {
+	case ::gfx::blur::type::Area:
+	case ::gfx::blur::type::Zoom:
+	case ::gfx::blur::type::Directional:
+		return true;
+	default:
+		return false;
+	}
+}
+
+double_t gfx::blur::gaussian_factory::get_min_step_scale_x(::gfx::blur::type)
+{
+	return double_t(0.01);
+}
+
+double_t gfx::blur::gaussian_factory::get_step_step_scale_x(::gfx::blur::type)
+{
+	return double_t(0.01);
+}
+
+double_t gfx::blur::gaussian_factory::get_max_step_scale_x(::gfx::blur::type)
+{
+	return double_t(1000.0);
+}
+
+double_t gfx::blur::gaussian_factory::get_min_step_scale_y(::gfx::blur::type)
+{
+	return double_t(0.01);
+}
+
+double_t gfx::blur::gaussian_factory::get_step_step_scale_y(::gfx::blur::type)
+{
+	return double_t(0.01);
+}
+
+double_t gfx::blur::gaussian_factory::get_max_step_scale_y(::gfx::blur::type)
+{
+	return double_t(1000.0);
+}
+
+std::shared_ptr<::gfx::blur::gaussian_data> gfx::blur::gaussian_factory::data()
+{
+	std::unique_lock<std::mutex>                ulock(m_data_lock);
+	std::shared_ptr<::gfx::blur::gaussian_data> data = m_data.lock();
+	if (!data) {
+		data   = std::make_shared<::gfx::blur::gaussian_data>();
+		m_data = data;
+	}
+	return data;
+}
+
+::gfx::blur::gaussian_factory& gfx::blur::gaussian_factory::get()
+{
+	static ::gfx::blur::gaussian_factory instance;
+	return instance;
+}
+
+gfx::blur::gaussian::gaussian()
+	: m_size(1.), m_step_scale({1., 1.}), m_data(::gfx::blur::gaussian_factory::get().data())
+{
+	m_rendertarget  = std::make_shared<gs::rendertarget>(GS_RGBA, GS_ZS_NONE);
+	m_rendertarget2 = std::make_shared<gs::rendertarget>(GS_RGBA, GS_ZS_NONE);
+}
+
+gfx::blur::gaussian::~gaussian() {}
+
+void gfx::blur::gaussian::set_input(std::shared_ptr<::gs::texture> texture)
+{
+	m_input_texture = texture;
+}
+
+::gfx::blur::type gfx::blur::gaussian::get_type()
+{
+	return ::gfx::blur::type::Area;
+}
+
+double_t gfx::blur::gaussian::get_size()
+{
+	return m_size;
+}
+
+void gfx::blur::gaussian::set_size(double_t width)
+{
+	if (width < 1.)
+		width = 1.;
+	if (width > MAX_BLUR_SIZE)
+		width = MAX_BLUR_SIZE;
+	m_size = width;
+}
+
+void gfx::blur::gaussian::set_step_scale(double_t x, double_t y)
+{
+	m_step_scale.first  = x;
+	m_step_scale.second = y;
+}
+
+void gfx::blur::gaussian::get_step_scale(double_t& x, double_t& y)
+{
+	x = m_step_scale.first;
+	y = m_step_scale.second;
+}
+
+double_t gfx::blur::gaussian::get_step_scale_x()
+{
+	return m_step_scale.first;
+}
+
+double_t gfx::blur::gaussian::get_step_scale_y()
+{
+	return m_step_scale.second;
+}
+
+std::shared_ptr<::gs::texture> gfx::blur::gaussian::render()
+{
+	std::shared_ptr<::gs::effect> effect = m_data->get_effect();
+	auto                          kernel = m_data->get_kernel(size_t(m_size));
+
+	if (!effect || ((m_step_scale.first + m_step_scale.second) < FLT_EPSILON)) {
+		return m_input_texture;
+	}
+
+	float_t width  = float_t(m_input_texture->get_width());
+	float_t height = float_t(m_input_texture->get_height());
+
+	// Setup
+	obs_enter_graphics();
+	gs_set_cull_mode(GS_NEITHER);
+	gs_enable_color(true, true, true, true);
+	gs_enable_depth_test(false);
+	gs_depth_function(GS_ALWAYS);
+	gs_blend_state_push();
+	gs_reset_blend_state();
+	gs_enable_blending(false);
+	gs_blend_function(GS_BLEND_ONE, GS_BLEND_ZERO);
+	gs_enable_stencil_test(false);
+	gs_enable_stencil_write(false);
+	gs_stencil_function(GS_STENCIL_BOTH, GS_ALWAYS);
+	gs_stencil_op(GS_STENCIL_BOTH, GS_ZERO, GS_ZERO, GS_ZERO);
+
+	effect->get_parameter("pImage").set_texture(m_input_texture);
+	effect->get_parameter("pStepScale").set_float2(float_t(m_step_scale.first), float_t(m_step_scale.second));
+	effect->get_parameter("pSize").set_float(float_t(m_size));
+	effect->get_parameter("pKernel").set_float_array(kernel.data(), MAX_KERNEL_SIZE);
+
+	// First Pass
+	if (m_step_scale.first > FLT_EPSILON) {
+		effect->get_parameter("pImageTexel").set_float2(float_t(1. / width), 0.);
+
+		{
+			auto op = m_rendertarget2->render(uint32_t(width), uint32_t(height));
+			gs_ortho(0, 1., 0, 1., 0, 1.);
+			while (gs_effect_loop(effect->get_object(), "Draw")) {
+				gs_draw_sprite(0, 0, 1, 1);
+			}
+		}
+
+		std::swap(m_rendertarget, m_rendertarget2);
+		effect->get_parameter("pImage").set_texture(m_rendertarget->get_texture());
+	}
+
+	// Second Pass
+	if (m_step_scale.second > FLT_EPSILON) {
+		effect->get_parameter("pImageTexel").set_float2(0., float_t(1. / height));
+
+		{
+			auto op = m_rendertarget2->render(uint32_t(width), uint32_t(height));
+			gs_ortho(0, 1., 0, 1., 0, 1.);
+			while (gs_effect_loop(effect->get_object(), "Draw")) {
+				gs_draw_sprite(0, 0, 1, 1);
+			}
+		}
+
+		std::swap(m_rendertarget, m_rendertarget2);
+	}
+
+	gs_blend_state_pop();
+	obs_leave_graphics();
+
+	return this->get();
+}
+
+std::shared_ptr<::gs::texture> gfx::blur::gaussian::get()
+{
+	return m_rendertarget->get_texture();
+}
+
+gfx::blur::gaussian_directional::gaussian_directional() : m_angle(0.) {}
+
+gfx::blur::gaussian_directional::~gaussian_directional() {}
+
+::gfx::blur::type gfx::blur::gaussian_directional::get_type()
+{
+	return ::gfx::blur::type::Directional;
+}
+
+double_t gfx::blur::gaussian_directional::get_angle()
+{
+	return RAD_TO_DEG(m_angle);
+}
+
+void gfx::blur::gaussian_directional::set_angle(double_t angle)
+{
+	m_angle = DEG_TO_RAD(angle);
+}
+
+std::shared_ptr<::gs::texture> gfx::blur::gaussian_directional::render()
+{
+	std::shared_ptr<::gs::effect> effect = m_data->get_effect();
+	auto                          kernel = m_data->get_kernel(size_t(m_size));
+
+	if (!effect || ((m_step_scale.first + m_step_scale.second) < FLT_EPSILON)) {
+		return m_input_texture;
+	}
+
+	float_t width  = float_t(m_input_texture->get_width());
+	float_t height = float_t(m_input_texture->get_height());
+
+	// Setup
+	obs_enter_graphics();
+	gs_set_cull_mode(GS_NEITHER);
+	gs_enable_color(true, true, true, true);
+	gs_enable_depth_test(false);
+	gs_depth_function(GS_ALWAYS);
+	gs_blend_state_push();
+	gs_reset_blend_state();
+	gs_enable_blending(false);
+	gs_blend_function(GS_BLEND_ONE, GS_BLEND_ZERO);
+	gs_enable_stencil_test(false);
+	gs_enable_stencil_write(false);
+	gs_stencil_function(GS_STENCIL_BOTH, GS_ALWAYS);
+	gs_stencil_op(GS_STENCIL_BOTH, GS_ZERO, GS_ZERO, GS_ZERO);
+
+	effect->get_parameter("pImage").set_texture(m_input_texture);
+	effect->get_parameter("pImageTexel")
+		.set_float2(float_t(1. / width * cos(m_angle)), float_t(1. / height * sin(m_angle)));
+	effect->get_parameter("pStepScale").set_float2(float_t(m_step_scale.first), float_t(m_step_scale.second));
+	effect->get_parameter("pSize").set_float(float_t(m_size));
+	effect->get_parameter("pKernel").set_float_array(kernel.data(), MAX_KERNEL_SIZE);
+
+	// First Pass
+	{
+		auto op = m_rendertarget->render(uint32_t(width), uint32_t(height));
+		gs_ortho(0, 1., 0, 1., 0, 1.);
+		while (gs_effect_loop(effect->get_object(), "Draw")) {
+			gs_draw_sprite(0, 0, 1, 1);
+		}
+	}
+
+	gs_blend_state_pop();
+	obs_leave_graphics();
+
+	return this->get();
+}
+
+::gfx::blur::type gfx::blur::gaussian_rotational::get_type()
+{
+	return ::gfx::blur::type::Rotational;
+}
+
+std::shared_ptr<::gs::texture> gfx::blur::gaussian_rotational::render()
+{
+	std::shared_ptr<::gs::effect> effect = m_data->get_effect();
+	auto                          kernel = m_data->get_kernel(size_t(m_size));
+
+	if (!effect || ((m_step_scale.first + m_step_scale.second) < FLT_EPSILON)) {
+		return m_input_texture;
+	}
+
+	float_t width  = float_t(m_input_texture->get_width());
+	float_t height = float_t(m_input_texture->get_height());
+
+	// Setup
+	obs_enter_graphics();
+	gs_set_cull_mode(GS_NEITHER);
+	gs_enable_color(true, true, true, true);
+	gs_enable_depth_test(false);
+	gs_depth_function(GS_ALWAYS);
+	gs_blend_state_push();
+	gs_reset_blend_state();
+	gs_enable_blending(false);
+	gs_blend_function(GS_BLEND_ONE, GS_BLEND_ZERO);
+	gs_enable_stencil_test(false);
+	gs_enable_stencil_write(false);
+	gs_stencil_function(GS_STENCIL_BOTH, GS_ALWAYS);
+	gs_stencil_op(GS_STENCIL_BOTH, GS_ZERO, GS_ZERO, GS_ZERO);
+
+	effect->get_parameter("pImage").set_texture(m_input_texture);
+	effect->get_parameter("pImageTexel").set_float2(float_t(1. / width), float_t(1. / height));
+	effect->get_parameter("pStepScale").set_float2(float_t(m_step_scale.first), float_t(m_step_scale.second));
+	effect->get_parameter("pSize").set_float(float_t(m_size));
+	effect->get_parameter("pAngle").set_float(float_t(m_angle / m_size));
+	effect->get_parameter("pCenter").set_float2(float_t(m_center.first), float_t(m_center.second));
+	effect->get_parameter("pKernel").set_float_array(kernel.data(), MAX_KERNEL_SIZE);
+
+	// First Pass
+	{
+		auto op = m_rendertarget->render(uint32_t(width), uint32_t(height));
+		gs_ortho(0, 1., 0, 1., 0, 1.);
+		while (gs_effect_loop(effect->get_object(), "Rotate")) {
+			gs_draw_sprite(0, 0, 1, 1);
+		}
+	}
+
+	gs_blend_state_pop();
+	obs_leave_graphics();
+
+	return this->get();
+}
+
+void gfx::blur::gaussian_rotational::set_center(double_t x, double_t y)
+{
+	m_center.first  = x;
+	m_center.second = y;
+}
+
+void gfx::blur::gaussian_rotational::get_center(double_t& x, double_t& y)
+{
+	x = m_center.first;
+	y = m_center.second;
+}
+
+double_t gfx::blur::gaussian_rotational::get_angle()
+{
+	return double_t(RAD_TO_DEG(m_angle));
+}
+
+void gfx::blur::gaussian_rotational::set_angle(double_t angle)
+{
+	m_angle = DEG_TO_RAD(angle);
+}
+
+::gfx::blur::type gfx::blur::gaussian_zoom::get_type()
+{
+	return ::gfx::blur::type::Zoom;
+}
+
+std::shared_ptr<::gs::texture> gfx::blur::gaussian_zoom::render()
+{
+	std::shared_ptr<::gs::effect> effect = m_data->get_effect();
+	auto                          kernel = m_data->get_kernel(size_t(m_size));
+
+	if (!effect || ((m_step_scale.first + m_step_scale.second) < FLT_EPSILON)) {
+		return m_input_texture;
+	}
+
+	float_t width  = float_t(m_input_texture->get_width());
+	float_t height = float_t(m_input_texture->get_height());
+
+	// Setup
+	obs_enter_graphics();
+	gs_set_cull_mode(GS_NEITHER);
+	gs_enable_color(true, true, true, true);
+	gs_enable_depth_test(false);
+	gs_depth_function(GS_ALWAYS);
+	gs_blend_state_push();
+	gs_reset_blend_state();
+	gs_enable_blending(false);
+	gs_blend_function(GS_BLEND_ONE, GS_BLEND_ZERO);
+	gs_enable_stencil_test(false);
+	gs_enable_stencil_write(false);
+	gs_stencil_function(GS_STENCIL_BOTH, GS_ALWAYS);
+	gs_stencil_op(GS_STENCIL_BOTH, GS_ZERO, GS_ZERO, GS_ZERO);
+
+	effect->get_parameter("pImage").set_texture(m_input_texture);
+	effect->get_parameter("pImageTexel").set_float2(float_t(1. / width), float_t(1. / height));
+	effect->get_parameter("pStepScale").set_float2(float_t(m_step_scale.first), float_t(m_step_scale.second));
+	effect->get_parameter("pSize").set_float(float_t(m_size));
+	effect->get_parameter("pCenter").set_float2(float_t(m_center.first), float_t(m_center.second));
+	effect->get_parameter("pKernel").set_float_array(kernel.data(), MAX_KERNEL_SIZE);
+
+	// First Pass
+	{
+		auto op = m_rendertarget->render(uint32_t(width), uint32_t(height));
+		gs_ortho(0, 1., 0, 1., 0, 1.);
+		while (gs_effect_loop(effect->get_object(), "Zoom")) {
+			gs_draw_sprite(0, 0, 1, 1);
+		}
+	}
+
+	gs_blend_state_pop();
+	obs_leave_graphics();
+
+	return this->get();
+}
+
+void gfx::blur::gaussian_zoom::set_center(double_t x, double_t y)
+{
+	m_center.first  = x;
+	m_center.second = y;
+}
+
+void gfx::blur::gaussian_zoom::get_center(double_t& x, double_t& y)
+{
+	x = m_center.first;
+	y = m_center.second;
+}

source/gfx/blur/gfx-blur-gaussian.hpp

@@ -0,0 +1,167 @@
+// Modern effects for a modern Streamer
+// Copyright (C) 2019 Michael Fabian Dirks
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+#pragma once
+#include <mutex>
+#include <vector>
+#include "gfx-blur-base.hpp"
+#include "obs/gs/gs-effect.hpp"
+#include "obs/gs/gs-rendertarget.hpp"
+#include "obs/gs/gs-texture.hpp"
+
+namespace gfx {
+	namespace blur {
+		class gaussian_data {
+			std::shared_ptr<::gs::effect>     m_effect;
+			std::vector<std::vector<float_t>> m_kernels;
+
+			public:
+			gaussian_data();
+			~gaussian_data();
+
+			std::shared_ptr<::gs::effect> get_effect();
+
+			std::vector<float_t> const& get_kernel(size_t width);
+		};
+
+		class gaussian_factory : public ::gfx::blur::ifactory {
+			std::mutex                                m_data_lock;
+			std::weak_ptr<::gfx::blur::gaussian_data> m_data;
+
+			public:
+			gaussian_factory();
+			virtual ~gaussian_factory();
+
+			virtual bool is_type_supported(::gfx::blur::type type) override;
+
+			virtual std::shared_ptr<::gfx::blur::ibase> create(::gfx::blur::type type) override;
+
+			virtual double_t get_min_size(::gfx::blur::type type) override;
+
+			virtual double_t get_step_size(::gfx::blur::type type) override;
+
+			virtual double_t get_max_size(::gfx::blur::type type) override;
+
+			virtual double_t get_min_angle(::gfx::blur::type type) override;
+
+			virtual double_t get_step_angle(::gfx::blur::type type) override;
+
+			virtual double_t get_max_angle(::gfx::blur::type type) override;
+
+			virtual bool is_step_scale_supported(::gfx::blur::type type) override;
+
+			virtual double_t get_min_step_scale_x(::gfx::blur::type type) override;
+
+			virtual double_t get_step_step_scale_x(::gfx::blur::type type) override;
+
+			virtual double_t get_max_step_scale_x(::gfx::blur::type type) override;
+
+			virtual double_t get_min_step_scale_y(::gfx::blur::type type) override;
+
+			virtual double_t get_step_step_scale_y(::gfx::blur::type type) override;
+
+			virtual double_t get_max_step_scale_y(::gfx::blur::type type) override;
+
+			std::shared_ptr<::gfx::blur::gaussian_data> data();
+
+			public: // Singleton
+			static ::gfx::blur::gaussian_factory& get();
+		};
+
+		class gaussian : public ::gfx::blur::ibase {
+			protected:
+			std::shared_ptr<::gfx::blur::gaussian_data> m_data;
+
+			double_t                            m_size;
+			std::pair<double_t, double_t>       m_step_scale;
+			std::shared_ptr<::gs::texture>      m_input_texture;
+			std::shared_ptr<::gs::rendertarget> m_rendertarget;
+
+			private:
+			std::shared_ptr<::gs::rendertarget> m_rendertarget2;
+
+			public:
+			gaussian();
+			virtual ~gaussian();
+
+			virtual void set_input(std::shared_ptr<::gs::texture> texture) override;
+
+			virtual ::gfx::blur::type get_type() override;
+
+			virtual double_t get_size() override;
+
+			virtual void set_size(double_t width) override;
+
+			virtual void set_step_scale(double_t x, double_t y) override;
+
+			virtual void get_step_scale(double_t& x, double_t& y) override;
+
+			virtual double_t get_step_scale_x() override;
+
+			virtual double_t get_step_scale_y() override;
+
+			virtual std::shared_ptr<::gs::texture> render() override;
+
+			virtual std::shared_ptr<::gs::texture> get() override;
+		};
+
+		class gaussian_directional : public ::gfx::blur::gaussian, public ::gfx::blur::ibase_angle {
+			double_t m_angle;
+
+			public:
+			gaussian_directional();
+			virtual ~gaussian_directional();
+
+			virtual ::gfx::blur::type get_type() override;
+
+			virtual double_t get_angle() override;
+			virtual void     set_angle(double_t angle) override;
+
+			virtual std::shared_ptr<::gs::texture> render() override;
+		};
+
+		class gaussian_rotational : public ::gfx::blur::gaussian,
+									public ::gfx::blur::ibase_angle,
+									public ::gfx::blur::ibase_center {
+			std::pair<double_t, double_t> m_center;
+			double_t                      m_angle;
+
+			public:
+			virtual ::gfx::blur::type get_type() override;
+
+			virtual void set_center(double_t x, double_t y) override;
+			virtual void get_center(double_t& x, double_t& y) override;
+
+			virtual double_t get_angle() override;
+			virtual void     set_angle(double_t angle) override;
+
+			virtual std::shared_ptr<::gs::texture> render() override;
+		};
+
+		class gaussian_zoom : public ::gfx::blur::gaussian, public ::gfx::blur::ibase_center {
+			std::pair<double_t, double_t> m_center;
+
+			public:
+			virtual ::gfx::blur::type get_type() override;
+
+			virtual void set_center(double_t x, double_t y) override;
+			virtual void get_center(double_t& x, double_t& y) override;
+
+			virtual std::shared_ptr<::gs::texture> render() override;
+		};
+	} // namespace blur
+} // namespace gfx