obs-filters: Add mask/blend filter

This filter allows the ability to use a texture to modify the video
output of a source, the ability to:
- apply a color-based mask (dark = transparent, light = opaque)
- apply a mask based upon the alpha of an image
- blend an image via subtraction, addition, or multiplication

plugins/obs-filters/mask-filter.c

@@ -0,0 +1,166 @@
+#include <obs-module.h>
+#include <graphics/vec4.h>
+#include <util/dstr.h>
+
+#define SETTING_TYPE                   "type"
+#define SETTING_IMAGE_PATH             "image_path"
+#define SETTING_COLOR                  "color"
+#define SETTING_OPACITY                "opacity"
+
+#define TEXT_TYPE                      obs_module_text("Type")
+#define TEXT_IMAGE_PATH                obs_module_text("Path")
+#define TEXT_COLOR                     obs_module_text("Color")
+#define TEXT_OPACITY                   obs_module_text("Opacity")
+#define TEXT_PATH_IMAGES               obs_module_text("BrowsePath.Images")
+#define TEXT_PATH_ALL_FILES            obs_module_text("BrowsePath.AllFiles")
+
+struct mask_filter_data {
+	obs_source_t                   *context;
+	gs_effect_t                    *effect;
+
+	gs_texture_t                   *target;
+	struct vec4                    color;
+};
+
+static const char *mask_filter_get_name(void)
+{
+	return obs_module_text("MaskFilter");
+}
+
+static void mask_filter_update(void *data, obs_data_t *settings)
+{
+	struct mask_filter_data *filter = data;
+
+	const char *path = obs_data_get_string(settings, SETTING_IMAGE_PATH);
+	const char *effect_file = obs_data_get_string(settings, SETTING_TYPE);
+	uint32_t color = (uint32_t)obs_data_get_int(settings, SETTING_COLOR);
+	int opacity = (int)obs_data_get_int(settings, SETTING_OPACITY);
+	char *effect_path;
+
+	color |= (uint32_t)(((double)opacity) * 2.55) << 24;
+
+	vec4_from_rgba(&filter->color, color);
+
+	obs_enter_graphics();
+
+	gs_texture_destroy(filter->target);
+	filter->target = (path) ? gs_texture_create_from_file(path) : NULL;
+
+	effect_path = obs_module_file(effect_file);
+	gs_effect_destroy(filter->effect);
+	filter->effect = gs_effect_create_from_file(effect_path, NULL);
+	bfree(effect_path);
+
+	obs_leave_graphics();
+}
+
+static void mask_filter_defaults(obs_data_t *settings)
+{
+	obs_data_set_default_string(settings, SETTING_TYPE,
+			"mask_color_filter.effect");
+	obs_data_set_default_int(settings, SETTING_COLOR, 0xFFFFFF);
+	obs_data_set_default_int(settings, SETTING_OPACITY, 100);
+}
+
+#define IMAGE_FILTER_EXTENSIONS \
+	" (*.bmp *.jpg *.jpeg *.tga *.gif *.png)"
+
+static obs_properties_t *mask_filter_properties(void *data)
+{
+	obs_properties_t *props = obs_properties_create();
+	struct dstr filter_str = {0};
+	obs_property_t *p;
+
+	dstr_copy(&filter_str, TEXT_PATH_IMAGES);
+	dstr_cat(&filter_str, IMAGE_FILTER_EXTENSIONS ";;");
+	dstr_cat(&filter_str, TEXT_PATH_ALL_FILES);
+	dstr_cat(&filter_str, " (*.*)");
+
+	p = obs_properties_add_list(props, SETTING_TYPE, TEXT_TYPE,
+			OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
+
+	obs_property_list_add_string(p,
+			obs_module_text("MaskBlendType.MaskColor"),
+			"mask_color_filter.effect");
+	obs_property_list_add_string(p,
+			obs_module_text("MaskBlendType.MaskAlpha"),
+			"mask_alpha_filter.effect");
+	obs_property_list_add_string(p,
+			obs_module_text("MaskBlendType.BlendMultiply"),
+			"blend_mul_filter.effect");
+	obs_property_list_add_string(p,
+			obs_module_text("MaskBlendType.BlendAddition"),
+			"blend_add_filter.effect");
+	obs_property_list_add_string(p,
+			obs_module_text("MaskBlendType.BlendSubtraction"),
+			"blend_sub_filter.effect");
+
+	obs_properties_add_path(props, SETTING_IMAGE_PATH, TEXT_IMAGE_PATH,
+			OBS_PATH_FILE, filter_str.array, NULL);
+	obs_properties_add_color(props, SETTING_COLOR, TEXT_COLOR);
+	obs_properties_add_int(props, SETTING_OPACITY, TEXT_OPACITY, 0, 100, 1);
+
+	dstr_free(&filter_str);
+
+	UNUSED_PARAMETER(data);
+	return props;
+}
+
+static void *mask_filter_create(obs_data_t *settings, obs_source_t *context)
+{
+	struct mask_filter_data *filter =
+		bzalloc(sizeof(struct mask_filter_data));
+	filter->context = context;
+
+	obs_source_update(context, settings);
+	return filter;
+}
+
+static void mask_filter_destroy(void *data)
+{
+	struct mask_filter_data *filter = data;
+
+	obs_enter_graphics();
+	gs_effect_destroy(filter->effect);
+	gs_texture_destroy(filter->target);
+	obs_leave_graphics();
+
+	bfree(filter);
+}
+
+static void mask_filter_render(void *data, gs_effect_t *effect)
+{
+	struct mask_filter_data *filter = data;
+	gs_eparam_t *param;
+
+	if (!filter->target || !filter->effect) {
+		obs_source_skip_video_filter(filter->context);
+		return;
+	}
+
+	obs_source_process_filter_begin(filter->context, GS_RGBA,
+			OBS_ALLOW_DIRECT_RENDERING);
+
+	param = gs_effect_get_param_by_name(filter->effect, "target");
+	gs_effect_set_texture(param, filter->target);
+
+	param = gs_effect_get_param_by_name(filter->effect, "color");
+	gs_effect_set_vec4(param, &filter->color);
+
+	obs_source_process_filter_end(filter->context, filter->effect, 0, 0);
+
+	UNUSED_PARAMETER(effect);
+}
+
+struct obs_source_info mask_filter = {
+	.id                            = "mask_filter",
+	.type                          = OBS_SOURCE_TYPE_FILTER,
+	.output_flags                  = OBS_SOURCE_VIDEO,
+	.get_name                      = mask_filter_get_name,
+	.create                        = mask_filter_create,
+	.destroy                       = mask_filter_destroy,
+	.update                        = mask_filter_update,
+	.get_defaults                  = mask_filter_defaults,
+	.get_properties                = mask_filter_properties,
+	.video_render                  = mask_filter_render
+};