diff --git a/effects/blending.frag b/effects/blending.frag
index 132135c06..b418137b5 100644
--- a/effects/blending.frag
+++ b/effects/blending.frag
@@ -1,3 +1,5 @@
+#version 110
+
 const int BLEND_MODE_ADD = 0;
 const int BLEND_MODE_AVERAGE = 1;
 const int BLEND_MODE_COLORBURN = 2;
@@ -25,5 +27,11 @@ const int BLEND_MODE_SUBSTRACT = 23;
 const int BLEND_MODE_SUBTRACT = 24;
 const int BLEND_MODE_VIVIDLIGHT = 25;
 
+uniform sampler2D background;
+uniform sampler2D texture;
+varying vec2 vTexCoord;
+
 void main(void) {
+	gl_FragColor = texture2D(background, vTexCoord);
+	// gl_FragColor = texture2D(texture, vTexCoord)*2.0;
 }
\ No newline at end of file
diff --git a/project/effect.h b/project/effect.h
index f571a56df..dd681dc98 100644
--- a/project/effect.h
+++ b/project/effect.h
@@ -134,7 +134,7 @@ struct GLTextureCoords {
 	float textureBottomLeftQ;
 
 	int blendmode;
-	double opacity;
+	float opacity;
 };
 
 qint16 mix_audio_sample(qint16 a, qint16 b);
diff --git a/ui/renderfunctions.cpp b/ui/renderfunctions.cpp
index aab4b4c49..c480a6f69 100644
--- a/ui/renderfunctions.cpp
+++ b/ui/renderfunctions.cpp
@@ -93,35 +93,26 @@ void process_effect(QOpenGLContext* ctx,
 	}
 }
 
-GLuint compose_sequence(Viewer* viewer,
-						QOpenGLContext* ctx,
-						Sequence* seq,
-						QVector<Clip*>& nests,
-						bool video,
-						bool render_audio,
-						Effect** gizmos,
-						bool& texture_failed,
-						bool rendering,
-						int playback_speed) {
+GLuint compose_sequence(ComposeSequenceParams &params) {
 	GLint current_fbo = 0;
-	if (video) {
+	if (params.video) {
 		glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &current_fbo);
 	}
 
-	Sequence* s = seq;
+	Sequence* s = params.seq;
 	long playhead = s->playhead;
 
-	if (!nests.isEmpty()) {
-		for (int i=0;i<nests.size();i++) {
-			s = nests.at(i)->media->to_sequence();
-			playhead += nests.at(i)->clip_in - nests.at(i)->get_timeline_in_with_transition();
-			playhead = refactor_frame_number(playhead, nests.at(i)->sequence->frame_rate, s->frame_rate);
+	if (!params.nests.isEmpty()) {
+		for (int i=0;i<params.nests.size();i++) {
+			s = params.nests.at(i)->media->to_sequence();
+			playhead += params.nests.at(i)->clip_in - params.nests.at(i)->get_timeline_in_with_transition();
+			playhead = refactor_frame_number(playhead, params.nests.at(i)->sequence->frame_rate, s->frame_rate);
 		}
 
-		if (video && nests.last()->fbo != nullptr) {
-			nests.last()->fbo[0]->bind();
+		if (params.video && params.nests.last()->fbo != nullptr) {
+			params.nests.last()->fbo[0]->bind();
 			glClear(GL_COLOR_BUFFER_BIT);
-			ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
+			params.ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
 		}
 	}
 
@@ -134,7 +125,7 @@ GLuint compose_sequence(Viewer* viewer,
 
 		// if clip starts within one second and/or hasn't finished yet
 		if (c != nullptr) {
-			if ((c->track < 0) == video) {
+			if ((c->track < 0) == params.video) {
 				bool clip_is_active = false;
 
 				if (c->media != nullptr && c->media->get_type() == MEDIA_TYPE_FOOTAGE) {
@@ -146,7 +137,7 @@ GLuint compose_sequence(Viewer* viewer,
 								// if thread is already working, we don't want to touch this,
 								// but we also don't want to hang the UI thread
 								if (!c->open) {
-									open_clip(c, !rendering);
+									open_clip(c, !params.rendering);
 								}
 								clip_is_active = true;
 								if (c->track >= 0) audio_track_count++;
@@ -155,12 +146,12 @@ GLuint compose_sequence(Viewer* viewer,
 							}
 						} else {
 							//qWarning() << "Media '" + m->name + "' was not ready, retrying...";
-							texture_failed = true;
+							params.texture_failed = true;
 						}
 					}
 				} else {
 					if (is_clip_active(c, playhead)) {
-						if (!c->open) open_clip(c, !rendering);
+						if (!c->open) open_clip(c, !params.rendering);
 						clip_is_active = true;
 					} else if (c->finished_opening) {
 						close_clip(c, false);
@@ -186,7 +177,7 @@ GLuint compose_sequence(Viewer* viewer,
 	int half_width = s->width/2;
 	int half_height = s->height/2;
 
-	if (video) {
+	if (params.video) {
 		glPushMatrix();
 		glLoadIdentity();
 		glOrtho(-half_width, half_width, -half_height, half_height, -1, 10);
@@ -197,7 +188,7 @@ GLuint compose_sequence(Viewer* viewer,
 
 		if (c->media != nullptr && c->media->get_type() == MEDIA_TYPE_FOOTAGE && !c->finished_opening) {
 			qWarning() << "Tried to display clip" << i << "but it's closed";
-			texture_failed = true;
+			params.texture_failed = true;
 		} else {
 			if (c->track < 0) {
 				glColor4f(1.0, 1.0, 1.0, 1.0);
@@ -218,7 +209,7 @@ GLuint compose_sequence(Viewer* viewer,
 							c->texture->setMinMagFilters(QOpenGLTexture::Linear, QOpenGLTexture::Linear);
 							c->texture->allocateStorage(get_gl_pix_fmt_from_av(c->pix_fmt), QOpenGLTexture::UInt8);
 						}
-						get_clip_frame(c, qMax(playhead, c->timeline_in), texture_failed);
+						get_clip_frame(c, qMax(playhead, c->timeline_in), params.texture_failed);
 						textureID = c->texture->textureId();
 						break;
 					case MEDIA_TYPE_SEQUENCE:
@@ -229,7 +220,7 @@ GLuint compose_sequence(Viewer* viewer,
 
 				if (textureID == 0 && c->media != nullptr) {
 					qWarning() << "Texture hasn't been created yet";
-					texture_failed = true;
+					params.texture_failed = true;
 				} else if (playhead >= c->get_timeline_in_with_transition()) {
 					glPushMatrix();
 
@@ -238,7 +229,7 @@ GLuint compose_sequence(Viewer* viewer,
 						c->fbo = new QOpenGLFramebufferObject* [2];
 						c->fbo[0] = new QOpenGLFramebufferObject(video_width, video_height);
 						c->fbo[1] = new QOpenGLFramebufferObject(video_width, video_height);
-						ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
+						params.ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
 					}
 
 					bool fbo_switcher = false;
@@ -250,18 +241,18 @@ GLuint compose_sequence(Viewer* viewer,
 					if (c->media == nullptr) {
 						c->fbo[fbo_switcher]->bind();
 						glClear(GL_COLOR_BUFFER_BIT);
-						ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
+						params.ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
 						composite_texture = c->fbo[fbo_switcher]->texture();
 					} else {
 						// for nested sequences
 						if (c->media->get_type()== MEDIA_TYPE_SEQUENCE) {
-							nests.append(c);
-							textureID = compose_sequence(viewer, ctx, seq, nests, video, render_audio, gizmos, texture_failed, rendering, false);
-							nests.removeLast();
+							params.nests.append(c);
+							textureID = compose_sequence(params);
+							params.nests.removeLast();
 							fbo_switcher = true;
 						}
 
-						composite_texture = draw_clip(ctx, c->fbo[fbo_switcher], textureID, true);
+						composite_texture = draw_clip(params.ctx, c->fbo[fbo_switcher], textureID, true);
 					}
 
 					fbo_switcher = !fbo_switcher;
@@ -294,7 +285,7 @@ GLuint compose_sequence(Viewer* viewer,
 
 					for (int j=0;j<c->effects.size();j++) {
 						Effect* e = c->effects.at(j);
-						process_effect(ctx, c, e, timecode, coords, composite_texture, fbo_switcher, texture_failed, TA_NO_TRANSITION);
+						process_effect(params.ctx, c, e, timecode, coords, composite_texture, fbo_switcher, params.texture_failed, TA_NO_TRANSITION);
 
 						if (e->are_gizmos_enabled()) {
 							if (first_gizmo_effect == nullptr) first_gizmo_effect = e;
@@ -303,28 +294,28 @@ GLuint compose_sequence(Viewer* viewer,
 					}
 
 					if (selected_effect != nullptr) {
-						(*gizmos) = selected_effect;
+						(*params.gizmos) = selected_effect;
 					} else if (is_clip_selected(c, true)) {
-						(*gizmos) = first_gizmo_effect;
+						(*params.gizmos) = first_gizmo_effect;
 					}
 
 					if (c->get_opening_transition() != nullptr) {
 						int transition_progress = playhead - c->get_timeline_in_with_transition();
 						if (transition_progress < c->get_opening_transition()->get_length()) {
-							process_effect(ctx, c, c->get_opening_transition(), (double)transition_progress/(double)c->get_opening_transition()->get_length(), coords, composite_texture, fbo_switcher, texture_failed, TA_OPENING_TRANSITION);
+							process_effect(params.ctx, c, c->get_opening_transition(), (double)transition_progress/(double)c->get_opening_transition()->get_length(), coords, composite_texture, fbo_switcher, params.texture_failed, TA_OPENING_TRANSITION);
 						}
 					}
 
 					if (c->get_closing_transition() != nullptr) {
 						int transition_progress = playhead - (c->get_timeline_out_with_transition() - c->get_closing_transition()->get_length());
 						if (transition_progress >= 0 && transition_progress < c->get_closing_transition()->get_length()) {
-							process_effect(ctx, c, c->get_closing_transition(), (double)transition_progress/(double)c->get_closing_transition()->get_length(), coords, composite_texture, fbo_switcher, texture_failed, TA_CLOSING_TRANSITION);
+							process_effect(params.ctx, c, c->get_closing_transition(), (double)transition_progress/(double)c->get_closing_transition()->get_length(), coords, composite_texture, fbo_switcher, params.texture_failed, TA_CLOSING_TRANSITION);
 						}
 					}
 					// EFFECT CODE END
 
-					if (!nests.isEmpty()) {
-						nests.last()->fbo[0]->bind();
+					if (!params.nests.isEmpty()) {
+						params.nests.last()->fbo[0]->bind();
 					}
 					glViewport(0, 0, s->width, s->height);
 
@@ -333,10 +324,16 @@ GLuint compose_sequence(Viewer* viewer,
 					glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 					glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
-					glBegin(GL_QUADS);
+					// get current color attachment from framebuffer
+					GLint texture_id;
+					params.ctx->functions()->glGetFramebufferAttachmentParameteriv(GL_TEXTURE_2D, GL_COLOR_ATTACHMENT0, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME, &texture_id);
 
-					QOpenGLShaderProgram program;
-					program.bind();
+					params.blend_mode_program->bind();
+					params.blend_mode_program->setUniformValue("blend_mode", coords.blendmode);
+					params.blend_mode_program->setUniformValue("opacity", coords.opacity);
+//					blend_mode_program->setUniformValue("background", texture_id);
+
+					glBegin(GL_QUADS);
 
 					if (coords.grid_size <= 1) {
 						float z = 0.0f;
@@ -382,44 +379,44 @@ GLuint compose_sequence(Viewer* viewer,
 						}
 					}
 
-					program.release();
-
 					glEnd();
 
+					params.blend_mode_program->release();
+
 					glBindTexture(GL_TEXTURE_2D, 0); // unbind texture
 
 					// prepare gizmos
-					if ((*gizmos) != nullptr
-							&& nests.isEmpty()
-							&& ((*gizmos) == first_gizmo_effect
-							|| (*gizmos) == selected_effect)) {
-						(*gizmos)->gizmo_draw(timecode, coords); // set correct gizmo coords
-						(*gizmos)->gizmo_world_to_screen(); // convert gizmo coords to screen coords
+					if ((*params.gizmos) != nullptr
+							&& params.nests.isEmpty()
+							&& ((*params.gizmos) == first_gizmo_effect
+							|| (*params.gizmos) == selected_effect)) {
+						(*params.gizmos)->gizmo_draw(timecode, coords); // set correct gizmo coords
+						(*params.gizmos)->gizmo_world_to_screen(); // convert gizmo coords to screen coords
 					}
 
-					if (!nests.isEmpty()) {
-						ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
+					if (!params.nests.isEmpty()) {
+						params.ctx->functions()->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, current_fbo);
 					}
 
 					glPopMatrix();
 				}
 			} else {
-				if (render_audio || (config.enable_audio_scrubbing && audio_scrub && seq->playhead > c->timeline_in)) {
+				if (params.render_audio || (config.enable_audio_scrubbing && audio_scrub && params.seq->playhead > c->timeline_in)) {
 					if (c->media != nullptr && c->media->get_type() == MEDIA_TYPE_SEQUENCE) {
-						nests.append(c);
-						compose_sequence(viewer, ctx, seq, nests, video, render_audio, gizmos, texture_failed, rendering, playback_speed);
-						nests.removeLast();
+						params.nests.append(c);
+						compose_sequence(params);
+						params.nests.removeLast();
 					} else {
 						if (c->lock.tryLock()) {
 							// clip is not caching, start caching audio
-							cache_clip(c, playhead, c->audio_reset, !render_audio, nests, playback_speed);
+							cache_clip(c, playhead, c->audio_reset, !params.render_audio, params.nests, params.playback_speed);
 							c->lock.unlock();
 						}
 					}
 				}
 
 				// visually update all the keyframe values
-				if (c->sequence == seq) { // only if you can currently see them
+				if (c->sequence == params.seq) { // only if you can currently see them
 					double ts = (playhead - c->get_timeline_in_with_transition() + c->get_clip_in_with_transition())/s->frame_rate;
 					for (int i=0;i<c->effects.size();i++) {
 						Effect* e = c->effects.at(i);
@@ -435,24 +432,32 @@ GLuint compose_sequence(Viewer* viewer,
 		}
 	}
 
-	if (audio_track_count == 0 && viewer != nullptr) {
-		viewer->play_wake();
+	if (audio_track_count == 0 && params.viewer != nullptr) {
+		params.viewer->play_wake();
 	}
 
-	if (video) {
+	if (params.video) {
 		glPopMatrix();
 	}
 
-	if (!nests.isEmpty() && nests.last()->fbo != nullptr) {
+	if (!params.nests.isEmpty() && params.nests.last()->fbo != nullptr) {
 		// returns nested clip's texture
-		return nests.last()->fbo[0]->texture();
+		return params.nests.last()->fbo[0]->texture();
 	}
 
 	return 0;
 }
 
 void compose_audio(Viewer* viewer, Sequence* seq, bool render_audio, int playback_speed) {
-	QVector<Clip*> nests;
-	bool texture_failed;
-	compose_sequence(viewer, nullptr, seq, nests, false, render_audio, nullptr, texture_failed, audio_rendering, playback_speed);
+	ComposeSequenceParams params;
+	params.viewer = viewer;
+	params.ctx = nullptr;
+	params.seq = seq;
+	params.video = false;
+	params.render_audio = render_audio;
+	params.gizmos = nullptr;
+	params.rendering = audio_rendering;
+	params.playback_speed = playback_speed;
+	params.blend_mode_program = nullptr;
+	compose_sequence(params);
 }
diff --git a/ui/renderfunctions.h b/ui/renderfunctions.h
index 6523a16ba..52698d3f8 100644
--- a/ui/renderfunctions.h
+++ b/ui/renderfunctions.h
@@ -6,19 +6,29 @@
 
 class Effect;
 class Viewer;
+class QOpenGLShaderProgram;
 struct Sequence;
 struct Clip;
 
-GLuint compose_sequence(Viewer* viewer,
-						QOpenGLContext* ctx,
-						Sequence* seq,
-						QVector<Clip*>& nests,
-						bool video,
-						bool render_audio,
-						Effect **gizmos,
-						bool &texture_failed,
-						bool rendering,
-						int playback_speed);
+struct ComposeSequenceParams {
+	Viewer* viewer;
+	QOpenGLContext* ctx;
+	Sequence* seq;
+	QVector<Clip*> nests;
+	bool video;
+	bool render_audio;
+	Effect** gizmos;
+	bool texture_failed;
+	bool rendering;
+	int playback_speed;
+	QOpenGLShaderProgram* blend_mode_program;
+	GLuint backend_buffer1;
+	GLuint backend_attachment1;
+	GLuint backend_buffer2;
+	GLuint backend_attachment2;
+};
+
+GLuint compose_sequence(ComposeSequenceParams &params);
 
 void compose_audio(Viewer* viewer, Sequence* seq, bool render_audio, int playback_speed);
 
diff --git a/ui/renderthread.cpp b/ui/renderthread.cpp
index a4ee4da23..601f40c69 100644
--- a/ui/renderthread.cpp
+++ b/ui/renderthread.cpp
@@ -15,6 +15,7 @@ RenderThread::RenderThread() :
 	gizmos(nullptr),
 	share_ctx(nullptr),
 	ctx(nullptr),
+	blend_mode_program(nullptr),
 	seq(nullptr),
 	tex_width(-1),
 	tex_height(-1),
@@ -73,6 +74,14 @@ void RenderThread::run() {
 					glBindTexture(GL_TEXTURE_2D, 0);
 				}
 
+				if (blend_mode_program == nullptr) {
+					delete_shader_program();
+					blend_mode_program = new QOpenGLShaderProgram();
+					blend_mode_program->addShaderFromSourceFile(QOpenGLShader::Vertex, "C:/msys64/home/Matt/olive/effects/common.vert");
+					blend_mode_program->addShaderFromSourceFile(QOpenGLShader::Fragment, "C:/msys64/home/Matt/olive/effects/blending.frag");
+					blend_mode_program->link();
+				}
+
 				// draw
 				paint();
 
@@ -96,8 +105,6 @@ void RenderThread::run() {
 void RenderThread::paint() {
 	glLoadIdentity();
 
-	texture_failed = false;
-
 	glClearColor(0, 0, 0, 1);
 	glClear(GL_COLOR_BUFFER_BIT);
 
@@ -109,8 +116,21 @@ void RenderThread::paint() {
 	glEnable(GL_DEPTH);
 
 	gizmos = nullptr;
-	QVector<Clip*> nests;
-	compose_sequence(nullptr, ctx, seq, nests, true, false, &gizmos, texture_failed, false, temp_reverse);
+
+	ComposeSequenceParams params;
+	params.viewer = nullptr;
+	params.ctx = ctx;
+	params.seq = seq;
+	params.video = true;
+	params.texture_failed = false;
+	params.render_audio = false;
+	params.gizmos = &gizmos;
+	params.rendering = false;
+	params.playback_speed = 1;
+	params.blend_mode_program = blend_mode_program;
+	compose_sequence(params);
+
+	texture_failed = params.texture_failed;
 
 	if (!save_fn.isEmpty()) {
 		if (texture_failed) {
@@ -138,14 +158,12 @@ void RenderThread::paint() {
 	glDisable(GL_TEXTURE_2D);
 }
 
-void RenderThread::start_render(QOpenGLContext *share, Sequence *s, const QString& save, GLvoid* pixels, int idivider, bool itemp_reverse) {
+void RenderThread::start_render(QOpenGLContext *share, Sequence *s, const QString& save, GLvoid* pixels, int idivider) {
 	seq = s;
 
 	// stall any dependent actions
 	texture_failed = true;
 
-	temp_reverse = itemp_reverse;
-
 	if (share != nullptr && (ctx == nullptr || ctx->shareContext() != share_ctx)) {
 		share_ctx = share;
 		delete_ctx();
@@ -191,8 +209,16 @@ void RenderThread::delete_fbo() {
 	frameBuffer = 0;
 }
 
+void RenderThread::delete_shader_program() {
+	if (blend_mode_program != nullptr) {
+		delete blend_mode_program;
+	}
+	blend_mode_program = nullptr;
+}
+
 void RenderThread::delete_ctx() {
 	if (ctx != nullptr) {
+		delete_shader_program();
 		delete_texture();
 		delete_fbo();
 		ctx->doneCurrent();
diff --git a/ui/renderthread.h b/ui/renderthread.h
index 54eecd646..a73813888 100644
--- a/ui/renderthread.h
+++ b/ui/renderthread.h
@@ -7,6 +7,7 @@
 #include <QOffscreenSurface>
 #include <QOpenGLContext>
 #include <QOpenGLFramebufferObject>
+#include <QOpenGLShaderProgram>
 
 struct Sequence;
 class Effect;
@@ -22,7 +23,7 @@ public:
 	GLuint texColorBuffer;
 	Effect* gizmos;
 	void paint();
-	void start_render(QOpenGLContext* share, Sequence* s, const QString &save = nullptr, GLvoid *pixels = nullptr, int idivider = 0, bool itemp_reverse = false);
+	void start_render(QOpenGLContext* share, Sequence* s, const QString &save = nullptr, GLvoid *pixels = nullptr, int idivider = 0);
 	bool did_texture_fail();
 	void cancel();
 
@@ -35,11 +36,13 @@ private:
 	// cleanup functions
 	void delete_texture();
 	void delete_fbo();
+	void delete_shader_program();
 
 	QWaitCondition waitCond;
 	QOffscreenSurface surface;
 	QOpenGLContext* share_ctx;
 	QOpenGLContext* ctx;
+	QOpenGLShaderProgram* blend_mode_program;
 	Sequence* seq;
 	int divider;
 	int tex_width;
@@ -47,7 +50,6 @@ private:
 	bool queued;
 	bool texture_failed;
 	bool running;
-	bool temp_reverse;
 	QString save_fn;
 	GLvoid *pixel_buffer;
 };