From cdb27ac06b5e708e25c8036ef6931a103d7395ef Mon Sep 17 00:00:00 2001
From: jp9000 <obs.jim@gmail.com>
Date: Sat, 14 Mar 2015 00:23:09 -0700
Subject: [PATCH] libobs: Add functions to push/pop blend states

This is particularly important for the filter pipeline in order to
ensure that when the last filter is reached that the original blend
state is properly reset.
---
 libobs/graphics/graphics-internal.h |  1 +
 libobs/graphics/graphics.c          | 26 ++++++++++++++++++++++++++
 libobs/graphics/graphics.h          |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/libobs/graphics/graphics-internal.h b/libobs/graphics/graphics-internal.h
index e4655f1cd..43155795c 100644
--- a/libobs/graphics/graphics-internal.h
+++ b/libobs/graphics/graphics-internal.h
@@ -292,4 +292,5 @@ struct graphics_subsystem {
 	volatile long          ref;
 
 	struct blend_state     cur_blend_state;
+	DARRAY(struct blend_state) blend_state_stack;
 };
diff --git a/libobs/graphics/graphics.c b/libobs/graphics/graphics.c
index 79d5b8a45..54092a7d1 100644
--- a/libobs/graphics/graphics.c
+++ b/libobs/graphics/graphics.c
@@ -213,6 +213,7 @@ void gs_destroy(graphics_t *graphics)
 	pthread_mutex_destroy(&graphics->effect_mutex);
 	da_free(graphics->matrix_stack);
 	da_free(graphics->viewport_stack);
+	da_free(graphics->blend_state_stack);
 	if (graphics->module)
 		os_dlclose(graphics->module);
 	bfree(graphics);
@@ -1002,6 +1003,31 @@ void gs_perspective(float angle, float aspect, float near, float far)
 			ymin, ymax, near, far);
 }
 
+void gs_blend_state_push(void)
+{
+	graphics_t *graphics = thread_graphics;
+	if (!graphics) return;
+
+	da_push_back(graphics->blend_state_stack, &graphics->cur_blend_state);
+}
+
+void gs_blend_state_pop(void)
+{
+	graphics_t *graphics = thread_graphics;
+	struct blend_state *state;
+
+	if (!graphics) return;
+
+	state = da_end(graphics->blend_state_stack);
+	if (!state)
+		return;
+
+	gs_enable_blending(state->enabled);
+	gs_blend_function(state->src, state->dest);
+
+	da_pop_back(graphics->blend_state_stack);
+}
+
 void gs_reset_blend_state(void)
 {
 	graphics_t *graphics = thread_graphics;
diff --git a/libobs/graphics/graphics.h b/libobs/graphics/graphics.h
index 7f7ad24c2..d4b560c7b 100644
--- a/libobs/graphics/graphics.h
+++ b/libobs/graphics/graphics.h
@@ -537,6 +537,8 @@ EXPORT void gs_cubetexture_set_image(gs_texture_t *cubetex, uint32_t side,
 
 EXPORT void gs_perspective(float fovy, float aspect, float znear, float zfar);
 
+EXPORT void gs_blend_state_push(void);
+EXPORT void gs_blend_state_pop(void);
 EXPORT void gs_reset_blend_state(void);
 
 /* -------------------------- */