UI: desaturate toolbar icons that the mouse is not over.

This does not look great with light toolbar buttons as in the default,
so consider this a work in progress.

7 files changed, 45 insertions, 16 deletions

diff --git a/source/blender/editors/include/UI_interface_icons.h b/source/blender/editors/include/UI_interface_icons.h
index 5af2bcb27a1..a17eb6be618 100644
--- a/source/blender/editors/include/UI_interface_icons.h
+++ b/source/blender/editors/include/UI_interface_icons.h
@@ -76,6 +76,7 @@ void UI_icon_draw_preview_aspect_size(float x, float y, int icon_id, float aspec
 void UI_icon_draw_aspect(float x, float y, int icon_id, float aspect, float alpha);
 void UI_icon_draw_aspect_color(float x, float y, int icon_id, float aspect, const float rgb[3]);
 void UI_icon_draw_size(float x, float y, int size, int icon_id, float alpha);
+void UI_icon_draw_desaturate(float x, float y, int icon_id, float aspect, float alpha);
 void UI_icons_free(void);
 void UI_icons_free_drawinfo(void *drawinfo);
 
diff --git a/source/blender/editors/interface/interface_icons.c b/source/blender/editors/interface/interface_icons.c
index e2d28fc7986..c78e49517c3 100644
--- a/source/blender/editors/interface/interface_icons.c
+++ b/source/blender/editors/interface/interface_icons.c
@@ -977,7 +977,7 @@ PreviewImage *UI_icon_to_preview(int icon_id)
 }
 
 static void icon_draw_rect(float x, float y, int w, int h, float UNUSED(aspect), int rw, int rh,
-                           unsigned int *rect, float alpha, const float rgb[3], const bool UNUSED(is_preview))
+                           unsigned int *rect, float alpha, const float rgb[3], const bool desaturate)
 {
 	ImBuf *ima = NULL;
 	int draw_w = w;
@@ -1026,7 +1026,8 @@ static void icon_draw_rect(float x, float y, int w, int h, float UNUSED(aspect),
 	UI_widgetbase_draw_cache_flush();
 
 	/* draw */
-	IMMDrawPixelsTexState state = immDrawPixelsTexSetup(GPU_SHADER_2D_IMAGE_COLOR);
+	GPUBuiltinShader shader = (desaturate) ? GPU_SHADER_2D_IMAGE_DESATURATE_COLOR : GPU_SHADER_2D_IMAGE_COLOR;
+	IMMDrawPixelsTexState state = immDrawPixelsTexSetup(shader);
 	immDrawPixelsTex(&state, draw_x, draw_y, draw_w, draw_h, GL_RGBA, GL_UNSIGNED_BYTE, GL_NEAREST, rect,
 	                 1.0f, 1.0f, col);
 
@@ -1192,7 +1193,7 @@ static int get_draw_size(enum eIconSizes size)
 
 static void icon_draw_size(
         float x, float y, int icon_id, float aspect, float alpha, const float rgb[3],
-        enum eIconSizes size, int draw_size, const bool UNUSED(nocreate), const bool is_preview)
+        enum eIconSizes size, int draw_size, const bool desaturate)
 {
 	bTheme *btheme = UI_GetTheme();
 	Icon *icon = NULL;
@@ -1250,7 +1251,7 @@ static void icon_draw_size(
 			di->data.geom.image_cache = ibuf;
 		}
 		glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-		icon_draw_rect(x, y, w, h, aspect, w, h, ibuf->rect, alpha, rgb, is_preview);
+		icon_draw_rect(x, y, w, h, aspect, w, h, ibuf->rect, alpha, rgb, desaturate);
 		glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 	}
 	else if (di->type == ICON_TYPE_TEXTURE) {
@@ -1269,7 +1270,7 @@ static void icon_draw_size(
 		if (!iimg->rect) return;  /* something has gone wrong! */
 
 		glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-		icon_draw_rect(x, y, w, h, aspect, iimg->w, iimg->h, iimg->rect, alpha, rgb, is_preview);
+		icon_draw_rect(x, y, w, h, aspect, iimg->w, iimg->h, iimg->rect, alpha, rgb, desaturate);
 		glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 	}
 	else if (di->type == ICON_TYPE_PREVIEW) {
@@ -1282,7 +1283,7 @@ static void icon_draw_size(
 			/* preview images use premul alpha ... */
 			glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
-			icon_draw_rect(x, y, w, h, aspect, pi->w[size], pi->h[size], pi->rect[size], alpha, rgb, is_preview);
+			icon_draw_rect(x, y, w, h, aspect, pi->w[size], pi->h[size], pi->rect[size], alpha, rgb, desaturate);
 			glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 		}
 	}
@@ -1528,21 +1529,26 @@ int UI_idcode_icon_get(const int idcode)
 
 static void icon_draw_at_size(
         float x, float y, int icon_id, float aspect, float alpha,
-        enum eIconSizes size, const bool nocreate)
+        enum eIconSizes size, const bool desaturate)
 {
 	int draw_size = get_draw_size(size);
-	icon_draw_size(x, y, icon_id, aspect, alpha, NULL, size, draw_size, nocreate, false);
+	icon_draw_size(x, y, icon_id, aspect, alpha, NULL, size, draw_size, desaturate);
 }
 
 void UI_icon_draw_aspect(float x, float y, int icon_id, float aspect, float alpha)
 {
-	icon_draw_at_size(x, y, icon_id, aspect, alpha, ICON_SIZE_ICON, 0);
+	icon_draw_at_size(x, y, icon_id, aspect, alpha, ICON_SIZE_ICON, false);
 }
 
 void UI_icon_draw_aspect_color(float x, float y, int icon_id, float aspect, const float rgb[3])
 {
 	int draw_size = get_draw_size(ICON_SIZE_ICON);
-	icon_draw_size(x, y, icon_id, aspect, 1.0f, rgb, ICON_SIZE_ICON, draw_size, false, false);
+	icon_draw_size(x, y, icon_id, aspect, 1.0f, rgb, ICON_SIZE_ICON, draw_size, false);
+}
+
+void UI_icon_draw_desaturate(float x, float y, int icon_id, float aspect, float alpha)
+{
+	icon_draw_at_size(x, y, icon_id, aspect, alpha, ICON_SIZE_ICON, true);
 }
 
 /* draws icon with dpi scale factor */
@@ -1558,21 +1564,21 @@ void UI_icon_draw_alpha(float x, float y, int icon_id, float alpha)
 
 void UI_icon_draw_size(float x, float y, int size, int icon_id, float alpha)
 {
-	icon_draw_size(x, y, icon_id, 1.0f, alpha, NULL, ICON_SIZE_ICON, size, true, false);
+	icon_draw_size(x, y, icon_id, 1.0f, alpha, NULL, ICON_SIZE_ICON, size, false);
 }
 
 void UI_icon_draw_preview(float x, float y, int icon_id)
 {
-	icon_draw_at_size(x, y, icon_id, 1.0f, 1.0f, ICON_SIZE_PREVIEW, 0);
+	icon_draw_at_size(x, y, icon_id, 1.0f, 1.0f, ICON_SIZE_PREVIEW, false);
 }
 
 void UI_icon_draw_preview_aspect(float x, float y, int icon_id, float aspect)
 {
-	icon_draw_at_size(x, y, icon_id, aspect, 1.0f, ICON_SIZE_PREVIEW, 0);
+	icon_draw_at_size(x, y, icon_id, aspect, 1.0f, ICON_SIZE_PREVIEW, false);
 }
 
 void UI_icon_draw_preview_aspect_size(float x, float y, int icon_id, float aspect, float alpha, int size)
 {
-	icon_draw_size(x, y, icon_id, aspect, alpha, NULL, ICON_SIZE_PREVIEW, size, false, true);
+	icon_draw_size(x, y, icon_id, aspect, alpha, NULL, ICON_SIZE_PREVIEW, size, false);
 }
 
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index 4c481ebc308..1ce4941554c 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -1317,14 +1317,18 @@ static void widget_draw_icon_ex(
 			xs = (int)(xs + 0.1f);
 			ys = (int)(ys + 0.1f);
 		}
-		
+
 		/* to indicate draggable */
 		if (but->dragpoin && (but->flag & UI_ACTIVE)) {
 			float rgb[3] = {1.25f, 1.25f, 1.25f};
 			UI_icon_draw_aspect_color(xs, ys, icon, aspect, rgb);
 		}
-		else
+		else if ((but->flag & (UI_ACTIVE | UI_SELECT | UI_SELECT_DRAW)) || !UI_but_is_tool(but)) {
 			UI_icon_draw_aspect(xs, ys, icon, aspect, alpha);
+		}
+		else {
+			UI_icon_draw_desaturate(xs, ys, icon, aspect, alpha);
+		}
 	}
 
 	if (show_menu_icon) {
diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index cf6bbc7cb94..575dff1e811 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -147,6 +147,7 @@ data_to_c_simple(shaders/gpu_shader_2D_image_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_image_rect_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_image_multi_rect_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_image_frag.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_image_desaturate_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_image_linear_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_image_shuffle_color_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_image_mask_uniform_color_frag.glsl SRC)
diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index 2c795b01a5d..59bf92aa672 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -114,6 +114,7 @@ typedef enum GPUBuiltinShader {
 	GPU_SHADER_2D_SMOOTH_COLOR_DITHER,
 	GPU_SHADER_2D_IMAGE,
 	GPU_SHADER_2D_IMAGE_COLOR,
+	GPU_SHADER_2D_IMAGE_DESATURATE_COLOR,
 	GPU_SHADER_2D_IMAGE_ALPHA_COLOR,
 	GPU_SHADER_2D_IMAGE_ALPHA,
 	GPU_SHADER_2D_IMAGE_RECT_COLOR,
diff --git a/source/blender/gpu/intern/gpu_shader.c b/source/blender/gpu/intern/gpu_shader.c
index 9f492b7af50..609aa529872 100644
--- a/source/blender/gpu/intern/gpu_shader.c
+++ b/source/blender/gpu/intern/gpu_shader.c
@@ -81,6 +81,7 @@ extern char datatoc_gpu_shader_3D_image_vert_glsl[];
 extern char datatoc_gpu_shader_image_frag_glsl[];
 extern char datatoc_gpu_shader_image_linear_frag_glsl[];
 extern char datatoc_gpu_shader_image_color_frag_glsl[];
+extern char datatoc_gpu_shader_image_desaturate_frag_glsl[];
 extern char datatoc_gpu_shader_image_varying_color_frag_glsl[];
 extern char datatoc_gpu_shader_image_alpha_color_frag_glsl[];
 extern char datatoc_gpu_shader_image_shuffle_color_frag_glsl[];
@@ -709,6 +710,8 @@ GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader)
 		                          datatoc_gpu_shader_image_frag_glsl },
 		[GPU_SHADER_2D_IMAGE_COLOR] = { datatoc_gpu_shader_2D_image_vert_glsl,
 		                                datatoc_gpu_shader_image_color_frag_glsl },
+		[GPU_SHADER_2D_IMAGE_DESATURATE_COLOR] = { datatoc_gpu_shader_2D_image_vert_glsl,
+		                                           datatoc_gpu_shader_image_desaturate_frag_glsl },
 		[GPU_SHADER_2D_IMAGE_ALPHA_COLOR] = { datatoc_gpu_shader_2D_image_vert_glsl,
 		                                      datatoc_gpu_shader_image_alpha_color_frag_glsl },
 		[GPU_SHADER_2D_IMAGE_ALPHA] = { datatoc_gpu_shader_2D_image_vert_glsl,
diff --git a/source/blender/gpu/shaders/gpu_shader_image_desaturate_frag.glsl b/source/blender/gpu/shaders/gpu_shader_image_desaturate_frag.glsl
new file mode 100644
index 00000000000..5b2ccb8ff3a
--- /dev/null
+++ b/source/blender/gpu/shaders/gpu_shader_image_desaturate_frag.glsl
@@ -0,0 +1,13 @@
+
+in vec2 texCoord_interp;
+out vec4 fragColor;
+
+uniform vec4 color;
+uniform sampler2D image;
+
+void main()
+{
+	vec4 tex = texture(image, texCoord_interp);
+	tex.rgb = 0.3333333 * vec3(tex.r + tex.g + tex.b);
+	fragColor = tex * color;
+}