Spreadsheet: new spreadsheet editor

This implements the MVP for the new spreadsheet editor (T85879). The functionality
is still very limited, but it proved to be useful already. A more complete picture
of where we want to go with the new editor can be found in T86279.

Supported features:
* Show point attributes of evaluated meshes (no original data, no other domains,
  no other geometry types, yet). Since only meshes are supported right now, the
  output of the Point Distribute is not shown, because it is a point cloud.
* Only show data for selected vertices when the mesh is in edit mode.
  Different parts of Blender keep track of selection state and original-indices with
  varying degrees of success. Therefore, when the selected-only filter is used, the
  result might be a bit confusing when using some modifiers or nodes. This will
  be improved in the future.
* All data is readonly. Since only evaluated data is displayed currently, it has to
  be readonly. However, this is not an inherent limitation of the spreadsheet editor.
  In the future editable data will be displayed as well.

Some boilerplate code for the new editor has been committed before in
rB9cb5f0a2282a7a84f7f8636b43a32bdc04b51cd5.

It would be good to let the spreadsheet editor mature for a couple of weeks as part
of the geometry nodes project. Then other modules are invited to show their own data
in the new editor!

Differential Revision: https://developer.blender.org/D10566

1 files changed, 304 insertions, 0 deletions

diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_draw.cc b/source/blender/editors/space_spreadsheet/spreadsheet_draw.cc
new file mode 100644
index 00000000000..d6379c740e8
--- /dev/null
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_draw.cc
@@ -0,0 +1,304 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+#include "UI_view2d.h"
+
+#include "GPU_immediate.h"
+
+#include "DNA_screen_types.h"
+#include "DNA_userdef_types.h"
+
+#include "BLI_rect.h"
+
+#include "spreadsheet_draw.hh"
+
+namespace blender::ed::spreadsheet {
+
+SpreadsheetDrawer::SpreadsheetDrawer()
+{
+  left_column_width = UI_UNIT_X * 2;
+  top_row_height = UI_UNIT_Y * 1.1f;
+  row_height = UI_UNIT_Y;
+}
+
+SpreadsheetDrawer::~SpreadsheetDrawer() = default;
+
+void SpreadsheetDrawer::draw_top_row_cell(int UNUSED(column_index),
+                                          const CellDrawParams &UNUSED(params)) const
+{
+}
+
+void SpreadsheetDrawer::draw_left_column_cell(int UNUSED(row_index),
+                                              const CellDrawParams &UNUSED(params)) const
+{
+}
+
+void SpreadsheetDrawer::draw_content_cell(int UNUSED(row_index),
+                                          int UNUSED(column_index),
+                                          const CellDrawParams &UNUSED(params)) const
+{
+}
+
+int SpreadsheetDrawer::column_width(int UNUSED(column_index)) const
+{
+  return 5 * UI_UNIT_X;
+}
+
+static void draw_index_column_background(const uint pos,
+                                         const ARegion *region,
+                                         const SpreadsheetDrawer &drawer)
+{
+  immUniformThemeColorShade(TH_BACK, 11);
+  immRecti(pos, 0, region->winy - drawer.top_row_height, drawer.left_column_width, 0);
+}
+
+static void draw_alternating_row_overlay(const uint pos,
+                                         const int scroll_offset_y,
+                                         const ARegion *region,
+                                         const SpreadsheetDrawer &drawer)
+{
+  immUniformThemeColor(TH_ROW_ALTERNATE);
+  GPU_blend(GPU_BLEND_ALPHA);
+  BLI_assert(drawer.row_height > 0);
+  const int row_pair_height = drawer.row_height * 2;
+  const int row_top_y = region->winy - drawer.top_row_height - scroll_offset_y % row_pair_height;
+  for (const int i : IndexRange(region->winy / row_pair_height + 1)) {
+    int x_left = 0;
+    int x_right = region->winx;
+    int y_top = row_top_y - i * row_pair_height - drawer.row_height;
+    int y_bottom = y_top - drawer.row_height;
+    y_top = std::min(y_top, region->winy - drawer.top_row_height);
+    y_bottom = std::min(y_bottom, region->winy - drawer.top_row_height);
+    immRecti(pos, x_left, y_top, x_right, y_bottom);
+  }
+  GPU_blend(GPU_BLEND_NONE);
+}
+
+static void draw_top_row_background(const uint pos,
+                                    const ARegion *region,
+                                    const SpreadsheetDrawer &drawer)
+{
+  immUniformThemeColorShade(TH_BACK, 11);
+  immRecti(pos, 0, region->winy, region->winx, region->winy - drawer.top_row_height);
+}
+
+static void draw_separator_lines(const uint pos,
+                                 const int scroll_offset_x,
+                                 const ARegion *region,
+                                 const SpreadsheetDrawer &drawer)
+{
+  immUniformThemeColorShade(TH_BACK, -11);
+
+  immBeginAtMost(GPU_PRIM_LINES, drawer.tot_columns * 2 + 4);
+
+  /* Left column line. */
+  immVertex2i(pos, drawer.left_column_width, region->winy);
+  immVertex2i(pos, drawer.left_column_width, 0);
+
+  /* Top row line. */
+  immVertex2i(pos, 0, region->winy - drawer.top_row_height);
+  immVertex2i(pos, region->winx, region->winy - drawer.top_row_height);
+
+  /* Column separator lines. */
+  int line_x = drawer.left_column_width - scroll_offset_x;
+  for (const int column_index : IndexRange(drawer.tot_columns)) {
+    const int column_width = drawer.column_width(column_index);
+    line_x += column_width;
+    if (line_x >= drawer.left_column_width) {
+      immVertex2i(pos, line_x, region->winy);
+      immVertex2i(pos, line_x, 0);
+    }
+  }
+  immEnd();
+}
+
+static void get_visible_rows(const SpreadsheetDrawer &drawer,
+                             const ARegion *region,
+                             const int scroll_offset_y,
+                             int *r_first_row,
+                             int *r_max_visible_rows)
+{
+  *r_first_row = -scroll_offset_y / drawer.row_height;
+  *r_max_visible_rows = region->winy / drawer.row_height + 1;
+}
+
+static void draw_left_column_content(const int scroll_offset_y,
+                                     const bContext *C,
+                                     ARegion *region,
+                                     const SpreadsheetDrawer &drawer)
+{
+  GPU_scissor_test(true);
+  GPU_scissor(0, 0, drawer.left_column_width, region->winy - drawer.top_row_height);
+
+  uiBlock *left_column_block = UI_block_begin(C, region, __func__, UI_EMBOSS_NONE);
+  int first_row, max_visible_rows;
+  get_visible_rows(drawer, region, scroll_offset_y, &first_row, &max_visible_rows);
+  for (const int row_index : IndexRange(first_row, max_visible_rows)) {
+    if (row_index >= drawer.tot_rows) {
+      break;
+    }
+    CellDrawParams params;
+    params.block = left_column_block;
+    params.xmin = 0;
+    params.ymin = region->winy - drawer.top_row_height - (row_index + 1) * drawer.row_height -
+                  scroll_offset_y;
+    params.width = drawer.left_column_width;
+    params.height = drawer.row_height;
+    drawer.draw_left_column_cell(row_index, params);
+  }
+
+  UI_block_end(C, left_column_block);
+  UI_block_draw(C, left_column_block);
+
+  GPU_scissor_test(false);
+}
+
+static void draw_top_row_content(const bContext *C,
+                                 ARegion *region,
+                                 const SpreadsheetDrawer &drawer,
+                                 const int scroll_offset_x)
+{
+  GPU_scissor_test(true);
+  GPU_scissor(drawer.left_column_width + 1,
+              region->winy - drawer.top_row_height,
+              region->winx - drawer.left_column_width,
+              drawer.top_row_height);
+
+  uiBlock *first_row_block = UI_block_begin(C, region, __func__, UI_EMBOSS_NONE);
+
+  int left_x = drawer.left_column_width - scroll_offset_x;
+  for (const int column_index : IndexRange(drawer.tot_columns)) {
+    const int column_width = drawer.column_width(column_index);
+    const int right_x = left_x + column_width;
+
+    CellDrawParams params;
+    params.block = first_row_block;
+    params.xmin = left_x;
+    params.ymin = region->winy - drawer.top_row_height;
+    params.width = column_width;
+    params.height = drawer.top_row_height;
+    drawer.draw_top_row_cell(column_index, params);
+
+    left_x = right_x;
+  }
+
+  UI_block_end(C, first_row_block);
+  UI_block_draw(C, first_row_block);
+
+  GPU_scissor_test(false);
+}
+
+static void draw_cell_contents(const bContext *C,
+                               ARegion *region,
+                               const SpreadsheetDrawer &drawer,
+                               const int scroll_offset_x,
+                               const int scroll_offset_y)
+{
+  GPU_scissor_test(true);
+  GPU_scissor(drawer.left_column_width + 1,
+              0,
+              region->winx - drawer.left_column_width,
+              region->winy - drawer.top_row_height);
+
+  uiBlock *cells_block = UI_block_begin(C, region, __func__, UI_EMBOSS_NONE);
+
+  int first_row, max_visible_rows;
+  get_visible_rows(drawer, region, scroll_offset_y, &first_row, &max_visible_rows);
+
+  int left_x = drawer.left_column_width - scroll_offset_x;
+  for (const int column_index : IndexRange(drawer.tot_columns)) {
+    const int column_width = drawer.column_width(column_index);
+    const int right_x = left_x + column_width;
+
+    if (right_x >= drawer.left_column_width && left_x <= region->winx) {
+      for (const int row_index : IndexRange(first_row, max_visible_rows)) {
+        if (row_index >= drawer.tot_rows) {
+          break;
+        }
+
+        CellDrawParams params;
+        params.block = cells_block;
+        params.xmin = left_x;
+        params.ymin = region->winy - drawer.top_row_height - (row_index + 1) * drawer.row_height -
+                      scroll_offset_y;
+        params.width = column_width;
+        params.height = drawer.row_height;
+        drawer.draw_content_cell(row_index, column_index, params);
+      }
+    }
+
+    left_x = right_x;
+  }
+
+  UI_block_end(C, cells_block);
+  UI_block_draw(C, cells_block);
+
+  GPU_scissor_test(false);
+}
+
+static void update_view2d_tot_rect(const SpreadsheetDrawer &drawer,
+                                   ARegion *region,
+                                   const int row_amount)
+{
+  int column_width_sum = 0;
+  for (const int column_index : IndexRange(drawer.tot_columns)) {
+    column_width_sum += drawer.column_width(column_index);
+  }
+
+  UI_view2d_totRect_set(&region->v2d,
+                        column_width_sum + drawer.left_column_width,
+                        row_amount * drawer.row_height + drawer.top_row_height);
+}
+
+void draw_spreadsheet_in_region(const bContext *C,
+                                ARegion *region,
+                                const SpreadsheetDrawer &drawer)
+{
+  update_view2d_tot_rect(drawer, region, drawer.tot_rows);
+
+  UI_ThemeClearColor(TH_BACK);
+
+  View2D *v2d = &region->v2d;
+  const int scroll_offset_y = v2d->cur.ymax;
+  const int scroll_offset_x = v2d->cur.xmin;
+
+  GPUVertFormat *format = immVertexFormat();
+  uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_I32, 2, GPU_FETCH_INT_TO_FLOAT);
+  immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
+
+  draw_index_column_background(pos, region, drawer);
+  draw_alternating_row_overlay(pos, scroll_offset_y, region, drawer);
+  draw_top_row_background(pos, region, drawer);
+  draw_separator_lines(pos, scroll_offset_x, region, drawer);
+
+  immUnbindProgram();
+
+  draw_left_column_content(scroll_offset_y, C, region, drawer);
+  draw_top_row_content(C, region, drawer, scroll_offset_x);
+  draw_cell_contents(C, region, drawer, scroll_offset_x, scroll_offset_y);
+
+  rcti scroller_mask;
+  BLI_rcti_init(&scroller_mask,
+                drawer.left_column_width,
+                region->winx,
+                0,
+                region->winy - drawer.top_row_height);
+  UI_view2d_scrollers_draw(v2d, &scroller_mask);
+}
+
+}  // namespace blender::ed::spreadsheet