Cleanup: GPU: Use explicit clear value in GPU_clear* commands

This replace `GPU_clear()` by `GPU_clear_color()` and `GPU_clear_depth()`.
Since we always set the clear value before clearing, it is unecessary
to track the clear color state.
Moreover, it makes it clearer what we clear the framebuffer to.

source/blender/draw/intern/draw_manager.c

@@ -1593,7 +1593,6 @@ void DRW_draw_render_loop_offscreen(struct Depsgraph *depsgraph,
      * be to do that in the colormanagmeent shader. */
     GPU_offscreen_bind(ofs, false);
     GPU_clear_color(0.0f, 0.0f, 0.0f, 1.0f);
-    GPU_clear(GPU_COLOR_BIT);
     /* Premult Alpha over black background. */
     GPU_blend(GPU_BLEND_ALPHA_PREMULT);
   }

source/blender/editors/gpencil/gpencil_fill.c

@@ -455,7 +455,7 @@ static bool gpencil_render_offscreen(tGPDfill *tgpf)
   GPU_matrix_identity_set();
 
   GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
-  GPU_clear(GPU_COLOR_BIT | GPU_DEPTH_BIT);
+  GPU_clear_depth(1.0f);
 
   ED_view3d_update_viewmat(
       tgpf->depsgraph, tgpf->scene, tgpf->v3d, tgpf->region, NULL, winmat, NULL, true);

source/blender/editors/include/UI_resources.h

@@ -431,12 +431,9 @@ void UI_GetColorPtrBlendShade3ubv(const unsigned char cp1[3],
 // (for anything fancy use UI_GetThemeColor[Fancy] then BLF_color)
 void UI_FontThemeColor(int fontid, int colorid);
 
-// clear the openGL ClearColor using the input colorid
+// clear the framebuffer using the input colorid
 void UI_ThemeClearColor(int colorid);
 
-// clear the openGL ClearColor using the input colorid using optional transparency
-void UI_ThemeClearColorAlpha(int colorid, float alpha);
-
 // internal (blender) usage only, for init and set active
 void UI_SetTheme(int spacetype, int regionid);
 

source/blender/editors/interface/interface_panel.c

@@ -1442,10 +1442,6 @@ void UI_panels_end(const bContext *C, ARegion *region, int *r_x, int *r_y)
 
 void UI_panels_draw(const bContext *C, ARegion *region)
 {
-  if (region->alignment != RGN_ALIGN_FLOAT) {
-    UI_ThemeClearColor(TH_BACK);
-  }
-
   /* Draw panels, selected on top. Also in reverse order, because
    * UI blocks are added in reverse order and we need child panels
    * to draw on top. */

source/blender/editors/interface/interface_region_hud.c

@@ -217,8 +217,7 @@ static void hud_region_draw(const bContext *C, ARegion *region)
 {
   UI_view2d_view_ortho(&region->v2d);
   wmOrtho2_region_pixelspace(region);
-  GPU_clear_color(0, 0, 0, 0.0f);
-  GPU_clear(GPU_COLOR_BIT);
+  GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
 
   if ((region->flag & RGN_FLAG_HIDDEN) == 0) {
     ui_draw_menu_back(NULL,

source/blender/editors/interface/resources.c

@@ -1474,13 +1474,6 @@ void UI_ThemeClearColor(int colorid)
   GPU_clear_color(col[0], col[1], col[2], 1.0f);
 }
 
-void UI_ThemeClearColorAlpha(int colorid, float alpha)
-{
-  float col[3];
-  UI_GetThemeColor3fv(colorid, col);
-  GPU_clear_color(col[0], col[1], col[2], alpha);
-}
-
 int UI_ThemeMenuShadowWidth(void)
 {
   bTheme *btheme = UI_GetTheme();

source/blender/editors/render/render_opengl.c

@@ -339,7 +339,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
       GPU_offscreen_bind(oglrender->ofs, true);
 
       GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
-      GPU_clear(GPU_COLOR_BIT | GPU_DEPTH_BIT);
+      GPU_clear_depth(1.0f);
 
       GPU_matrix_reset();
       wmOrtho2(0, scene->r.xsch, 0, scene->r.ysch);

source/blender/editors/screen/area.c

@@ -351,11 +351,9 @@ static void region_draw_status_text(ScrArea *area, ARegion *region)
 
   if (overlap) {
     GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
-    GPU_clear(GPU_COLOR_BIT);
   }
   else {
     UI_ThemeClearColor(TH_HEADER);
-    GPU_clear(GPU_COLOR_BIT);
   }
 
   int fontid = BLF_set_default();
@@ -519,7 +517,6 @@ void ED_region_do_draw(bContext *C, ARegion *region)
 
   if (area && area_is_pseudo_minimized(area)) {
     UI_ThemeClearColor(TH_EDITOR_OUTLINE);
-    GPU_clear(GPU_COLOR_BIT);
     return;
   }
   /* optional header info instead? */
@@ -2529,11 +2526,9 @@ static void region_clear_color(const bContext *C, const ARegion *region, ThemeCo
     float back[4];
     UI_GetThemeColor4fv(colorid, back);
     GPU_clear_color(back[3] * back[0], back[3] * back[1], back[3] * back[2], back[3]);
-    GPU_clear(GPU_COLOR_BIT);
   }
   else {
     UI_ThemeClearColor(colorid);
-    GPU_clear(GPU_COLOR_BIT);
   }
 }
 

source/blender/editors/screen/screen_draw.c

@@ -606,8 +606,8 @@ void ED_screen_preview_render(const bScreen *screen, int size_x, int size_y, uin
   GPUOffScreen *offscreen = GPU_offscreen_create(size_x, size_y, true, false, err_out);
 
   GPU_offscreen_bind(offscreen, true);
-  GPU_clear_color(0.0, 0.0, 0.0, 0.0);
-  GPU_clear(GPU_COLOR_BIT | GPU_DEPTH_BIT);
+  GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
+  GPU_clear_depth(1.0f);
 
   screen_preview_draw(screen, size_x, size_y);
 

source/blender/editors/space_action/space_action.c

@@ -191,7 +191,6 @@ static void action_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 
@@ -278,7 +277,6 @@ static void action_channel_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_clip/space_clip.c

@@ -926,7 +926,6 @@ static void clip_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   /* data... */
   movieclip_main_area_set_view2d(C, region);
@@ -1054,7 +1053,6 @@ static void graph_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 
@@ -1099,7 +1097,6 @@ static void dopesheet_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 
@@ -1172,7 +1169,6 @@ static void clip_channels_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_console/space_console.c

@@ -215,7 +215,6 @@ static void console_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   /* worlks best with no view2d matrix set */
   UI_view2d_view_ortho(v2d);

source/blender/editors/space_file/space_file.c

@@ -449,7 +449,6 @@ static void file_main_region_draw(const bContext *C, ARegion *region)
   FileSelectParams *params = ED_fileselect_get_params(sfile);
 
   View2D *v2d = &region->v2d;
-  float col[3];
 
   /* Needed, because filelist is not initialized on loading */
   if (!sfile->files || filelist_empty(sfile->files)) {
@@ -457,9 +456,7 @@ static void file_main_region_draw(const bContext *C, ARegion *region)
   }
 
   /* clear and setup matrix */
-  UI_GetThemeColor3fv(TH_BACK, col);
-  GPU_clear_color(col[0], col[1], col[2], 1.0f);
-  GPU_clear(GPU_COLOR_BIT);
+  UI_ThemeClearColor(TH_BACK);
 
   /* Allow dynamically sliders to be set, saves notifiers etc. */
 

source/blender/editors/space_graph/space_graph.c

@@ -200,12 +200,9 @@ static void graph_main_region_draw(const bContext *C, ARegion *region)
   Scene *scene = CTX_data_scene(C);
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  float col[3];
 
   /* clear and setup matrix */
-  UI_GetThemeColor3fv(TH_BACK, col);
-  GPU_clear_color(col[0], col[1], col[2], 1.0f);
-  GPU_clear(GPU_COLOR_BIT);
+  UI_ThemeClearColor(TH_BACK);
 
   UI_view2d_view_ortho(v2d);
 
@@ -358,12 +355,9 @@ static void graph_channel_region_draw(const bContext *C, ARegion *region)
 {
   bAnimContext ac;
   View2D *v2d = &region->v2d;
-  float col[3];
 
   /* clear and setup matrix */
-  UI_GetThemeColor3fv(TH_BACK, col);
-  GPU_clear_color(col[0], col[1], col[2], 1.0f);
-  GPU_clear(GPU_COLOR_BIT);
+  UI_ThemeClearColor(TH_BACK);
 
   UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_image/space_image.c

@@ -650,7 +650,6 @@ static void image_main_region_draw(const bContext *C, ARegion *region)
 
   GPU_framebuffer_bind(framebuffer_default);
   GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
-  GPU_clear(GPU_COLOR_BIT);
 
   GPU_framebuffer_bind(framebuffer_overlay);
 
@@ -661,7 +660,6 @@ static void image_main_region_draw(const bContext *C, ARegion *region)
   UI_GetThemeColor3fv(TH_BACK, col);
   srgb_to_linearrgb_v3_v3(col, col);
   GPU_clear_color(col[0], col[1], col[2], 1.0f);
-  GPU_clear(GPU_COLOR_BIT);
   GPU_depth_test(GPU_DEPTH_NONE);
 
   image_user_refresh_scene(C, sima);

source/blender/editors/space_info/info_draw.c

@@ -147,7 +147,6 @@ static int report_textview_begin(TextViewContext *tvc)
   tvc->iter = reports->list.last;
 
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   tvc->iter_tmp = 0;
   if (tvc->iter && report_textview_skip__internal(tvc)) {

source/blender/editors/space_info/space_info.c

@@ -142,7 +142,6 @@ static void info_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   /* quick way to avoid drawing if not bug enough */
   if (region->winy < 16) {

source/blender/editors/space_nla/space_nla.c

@@ -194,7 +194,6 @@ static void nla_channel_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 
@@ -238,7 +237,6 @@ static void nla_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_node/node_draw.c

@@ -1343,8 +1343,6 @@ static void node_draw_basis(const bContext *C,
     }
   }
 
-  UI_ThemeClearColor(color_id);
-
   UI_block_end(C, node->block);
   UI_block_draw(C, node->block);
   node->block = NULL;
@@ -1737,8 +1735,8 @@ void drawnodespace(const bContext *C, ARegion *region)
 
   UI_view2d_view_ortho(v2d);
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
   GPU_depth_test(GPU_DEPTH_NONE);
+  GPU_scissor_test(true);
 
   /* XXX snode->cursor set in coordspace for placing new nodes, used for drawing noodles too */
   UI_view2d_region_to_view(&region->v2d,

source/blender/editors/space_outliner/space_outliner.c

@@ -87,7 +87,6 @@ static void outliner_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   draw_outliner(C);
 

source/blender/editors/space_script/space_script.c

@@ -127,7 +127,6 @@ static void script_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_sequencer/sequencer_draw.c

@@ -1529,11 +1529,7 @@ static void sequencer_stop_running_jobs(const bContext *C, Scene *scene)
 
 static void sequencer_preview_clear(void)
 {
-  float col[3];
-
-  UI_GetThemeColor3fv(TH_SEQ_PREVIEW, col);
-  GPU_clear_color(col[0], col[1], col[2], 1.0f);
-  GPU_clear(GPU_COLOR_BIT);
+  UI_ThemeClearColor(TH_SEQ_PREVIEW);
 }
 
 static void sequencer_preview_get_rect(rctf *preview,
@@ -2266,7 +2262,6 @@ void draw_timeline_seq(const bContext *C, ARegion *region)
   else {
     GPU_clear_color(col[0], col[1], col[2], 0.0f);
   }
-  GPU_clear(GPU_COLOR_BIT);
 
   UI_view2d_view_ortho(v2d);
   /* Get timeline boundbox, needed for the scrollers. */

source/blender/editors/space_text/space_text.c

@@ -296,7 +296,6 @@ static void text_main_region_draw(const bContext *C, ARegion *region)
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
-  GPU_clear(GPU_COLOR_BIT);
 
   // UI_view2d_view_ortho(v2d);
 

source/blender/editors/space_view3d/view3d_draw.c

@@ -2319,7 +2319,7 @@ void ED_view3d_draw_depth_gpencil(Depsgraph *depsgraph, Scene *scene, ARegion *r
   /* Setup view matrix. */
   ED_view3d_draw_setup_view(NULL, NULL, depsgraph, scene, region, v3d, NULL, NULL, NULL);
 
-  GPU_clear(GPU_DEPTH_BIT);
+  GPU_clear_depth(1.0f);
 
   GPU_depth_test(GPU_DEPTH_LESS_EQUAL);
 

source/blender/editors/uvedit/uvedit_draw.c

@@ -553,7 +553,6 @@ void ED_uvedit_draw_main(SpaceImage *sima,
           view_layer, ((View3D *)NULL), &objects_len);
       if (objects_len > 0) {
         GPU_clear_depth(1.0f);
-        GPU_clear(GPU_DEPTH_BIT);
       }
 
       /* go over all objects and create the batches + add their areas to the total */

source/blender/gpu/GPU_framebuffer.h

@@ -225,7 +225,6 @@ void GPU_offscreen_viewport_data_get(GPUOffScreen *ofs,
 
 void GPU_clear_color(float red, float green, float blue, float alpha);
 void GPU_clear_depth(float depth);
-void GPU_clear(eGPUFrameBufferBits flags);
 
 void GPU_frontbuffer_read_pixels(
     int x, int y, int w, int h, int channels, eGPUDataFormat format, void *data);

source/blender/gpu/intern/gpu_framebuffer.cc

@@ -1117,18 +1117,22 @@ void GPU_offscreen_viewport_data_get(GPUOffScreen *ofs,
 
 void GPU_clear_color(float red, float green, float blue, float alpha)
 {
+  BLI_assert((GPU_write_mask_get() & GPU_WRITE_COLOR) != 0);
+
+  GPU_context_active_get()->state_manager->apply_state();
+
   glClearColor(red, green, blue, alpha);
+  glClear(GL_COLOR_BUFFER_BIT);
 }
 
 void GPU_clear_depth(float depth)
 {
-  glClearDepth(depth);
-}
+  BLI_assert((GPU_write_mask_get() & GPU_WRITE_DEPTH) != 0);
 
-void GPU_clear(eGPUFrameBufferBits flags)
-{
   GPU_context_active_get()->state_manager->apply_state();
-  glClear(convert_buffer_bits_to_gl(flags));
+
+  glClearDepth(depth);
+  glClear(GL_DEPTH_BUFFER_BIT);
 }
 
 void GPU_frontbuffer_read_pixels(

source/blender/gpu/intern/gpu_select_pick.c

@@ -339,7 +339,7 @@ void gpu_select_pick_begin(uint (*buffer)[4], uint bufsize, const rcti *input, c
 
     /* It's possible we don't want to clear depth buffer,
      * so existing elements are masked by current z-buffer. */
-    GPU_clear(GPU_DEPTH_BIT);
+    GPU_clear_depth(1.0f);
 
     /* scratch buffer (read new values here) */
     ps->gl.rect_depth_test = depth_buf_malloc(rect_len);
@@ -519,7 +519,7 @@ bool gpu_select_pick_load_id(uint id, bool end)
 
       if (g_pick_state.mode == GPU_SELECT_PICK_ALL) {
         /* we want new depths every time */
-        GPU_clear(GPU_DEPTH_BIT);
+        GPU_clear_depth(1.0f);
       }
     }
   }

source/blender/gpu/intern/gpu_select_sample_query.c

@@ -122,7 +122,7 @@ void gpu_select_query_begin(
   else if (mode == GPU_SELECT_NEAREST_FIRST_PASS) {
     GPU_depth_test(GPU_DEPTH_LESS_EQUAL);
     GPU_depth_mask(true);
-    GPU_clear(GPU_DEPTH_BIT);
+    GPU_clear_depth(1.0f);
   }
   else if (mode == GPU_SELECT_NEAREST_SECOND_PASS) {
     GPU_depth_test(GPU_DEPTH_EQUAL);

source/blender/windowmanager/intern/wm_draw.c

@@ -720,8 +720,7 @@ static void wm_draw_window_offscreen(bContext *C, wmWindow *win, bool stereo)
 
       wm_draw_region_buffer_create(region, false, false);
       wm_draw_region_bind(region, 0);
-      GPU_clear_color(0, 0, 0, 0);
-      GPU_clear(GPU_COLOR_BIT);
+      GPU_clear_color(0.0f, 0.0f, 0.0f, 0.0f);
       ED_region_do_draw(C, region);
       wm_draw_region_unbind(region);
 
@@ -744,7 +743,6 @@ static void wm_draw_window_onscreen(bContext *C, wmWindow *win, int view)
    * If it becomes a problem we should clear only when window size changes. */
 #if 0
   GPU_clear_color(0, 0, 0, 0);
-  GPU_clear(GPU_COLOR_BIT);
 #endif
 
   /* Blit non-overlapping area regions. */

source/blender/windowmanager/intern/wm_playanim.c

@@ -310,8 +310,7 @@ static void playanim_toscreen(
   CLAMP(offs_x, 0.0f, 1.0f);
   CLAMP(offs_y, 0.0f, 1.0f);
 
-  GPU_clear_color(0.1, 0.1, 0.1, 0.0);
-  GPU_clear(GPU_COLOR_BIT);
+  GPU_clear_color(0.1f, 0.1f, 0.1f, 0.0f);
 
   /* checkerboard for case alpha */
   if (ibuf->planes == 32) {
@@ -1313,8 +1312,7 @@ static char *wm_main_playanim_intern(int argc, const char **argv)
     maxwiny = ibuf->y * (1 + (maxwiny / ibuf->y));
   }
 
-  GPU_clear_color(0.1, 0.1, 0.1, 0.0);
-  GPU_clear(GPU_COLOR_BIT);
+  GPU_clear_color(0.1f, 0.1f, 0.1f, 0.0f);
 
   int win_x, win_y;
   playanim_window_get_size(&win_x, &win_y);

source/blender/windowmanager/intern/wm_window.c

@@ -645,11 +645,10 @@ static void wm_window_ghostwindow_add(wmWindowManager *wm,
       GHOST_SetWindowState(ghostwin, (GHOST_TWindowState)win->windowstate);
     }
 #endif
-    /* until screens get drawn, make it nice gray */
-    GPU_clear_color(0.55, 0.55, 0.55, 1.0f);
     /* Crash on OSS ATI: bugs.launchpad.net/ubuntu/+source/mesa/+bug/656100 */
     if (!GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_UNIX, GPU_DRIVER_OPENSOURCE)) {
-      GPU_clear(GPU_COLOR_BIT);
+      /* until screens get drawn, make it nice gray */
+      GPU_clear_color(0.55f, 0.55f, 0.55f, 1.0f);
     }
 
     /* needed here, because it's used before it reads userdef */

source/blender/windowmanager/xr/intern/wm_xr_draw.c

@@ -126,7 +126,7 @@ void wm_xr_draw_view(const GHOST_XrDrawViewInfo *draw_view, void *customdata)
   /* In case a framebuffer is still bound from drawing the last eye. */
   GPU_framebuffer_restore();
   /* Some systems have drawing glitches without this. */
-  GPU_clear(GPU_DEPTH_BIT);
+  GPU_clear_depth(1.0f);
 
   /* Draws the view into the surface_data->viewport's framebuffers */
   ED_view3d_draw_offscreen_simple(draw_data->depsgraph,