Fix T80825: UV Editor UV Grid

Regression introduced by D8234.

source/blender/draw/engines/overlay/overlay_grid.c

@@ -29,6 +29,8 @@
 #include "ED_image.h"
 #include "ED_view3d.h"
 
+#include "UI_resources.h"
+
 #include "overlay_private.h"
 
 enum {
@@ -61,7 +63,8 @@ void OVERLAY_grid_init(OVERLAY_Data *vedata)
     SpaceImage *sima = (SpaceImage *)draw_ctx->space_data;
     shd->grid_flag = ED_space_image_has_buffer(sima) ? 0 : PLANE_IMAGE | SHOW_GRID;
     shd->grid_distance = 1.0f;
-    shd->grid_mesh_size = 1.0f;
+    copy_v3_fl3(
+        shd->grid_size, (float)sima->tile_grid_shape[0], (float)sima->tile_grid_shape[1], 1.0f);
     for (int step = 0; step < 8; step++) {
       shd->grid_steps[step] = powf(4, step) * (1.0f / 16.0f);
     }
@@ -169,11 +172,11 @@ void OVERLAY_grid_init(OVERLAY_Data *vedata)
   }
 
   if (winmat[3][3] == 0.0f) {
-    shd->grid_mesh_size = dist;
+    copy_v3_fl(shd->grid_size, dist);
   }
   else {
     float viewdist = 1.0f / min_ff(fabsf(winmat[0][0]), fabsf(winmat[1][1]));
-    shd->grid_mesh_size = viewdist * dist;
+    copy_v3_fl(shd->grid_size, viewdist * dist);
   }
 
   shd->grid_distance = dist / 2.0f;
@@ -203,18 +206,19 @@ void OVERLAY_grid_cache_init(OVERLAY_Data *vedata)
   struct GPUBatch *geom = DRW_cache_grid_get();
 
   if (pd->is_image_editor) {
+    float mat[4][4];
+
     /* add quad background */
     sh = OVERLAY_shader_grid_image();
     grp = DRW_shgroup_create(sh, psl->grid_ps);
-    DRW_shgroup_call(grp, DRW_cache_quad_get(), NULL);
     float color_back[4];
     interp_v4_v4v4(color_back, G_draw.block.colorBackground, G_draw.block.colorGrid, 0.5);
     DRW_shgroup_uniform_vec4_copy(grp, "color", color_back);
-
-    /* add wire border */
-    grp = DRW_shgroup_create(sh, psl->grid_ps);
-    DRW_shgroup_call(grp, DRW_cache_quad_wires_get(), NULL);
-    DRW_shgroup_uniform_vec4_copy(grp, "color", G_draw.block.colorGrid);
+    unit_m4(mat);
+    mat[0][0] = shd->grid_size[0];
+    mat[1][1] = shd->grid_size[1];
+    mat[2][2] = shd->grid_size[2];
+    DRW_shgroup_call_obmat(grp, DRW_cache_quad_get(), mat);
   }
 
   sh = OVERLAY_shader_grid();
@@ -225,7 +229,7 @@ void OVERLAY_grid_cache_init(OVERLAY_Data *vedata)
   DRW_shgroup_uniform_vec3(grp, "planeAxes", shd->zplane_axes, 1);
   DRW_shgroup_uniform_float(grp, "gridDistance", &shd->grid_distance, 1);
   DRW_shgroup_uniform_float_copy(grp, "lineKernel", shd->grid_line_size);
-  DRW_shgroup_uniform_float_copy(grp, "meshSize", shd->grid_mesh_size);
+  DRW_shgroup_uniform_vec3(grp, "gridSize", shd->grid_size, 1);
   DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
   DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
   if (shd->zneg_flag) {
@@ -250,6 +254,26 @@ void OVERLAY_grid_cache_init(OVERLAY_Data *vedata)
   if (shd->zpos_flag) {
     DRW_shgroup_call(grp, geom, NULL);
   }
+
+  if (pd->is_image_editor) {
+    float theme_color[4];
+    UI_GetThemeColorShade4fv(TH_BACK, 60, theme_color);
+    srgb_to_linearrgb_v4(theme_color, theme_color);
+
+    float mat[4][4];
+    /* add wire border */
+    sh = OVERLAY_shader_grid_image();
+    grp = DRW_shgroup_create(sh, psl->grid_ps);
+    DRW_shgroup_uniform_vec4_copy(grp, "color", theme_color);
+    unit_m4(mat);
+    for (int x = 0; x < shd->grid_size[0]; x++) {
+      mat[3][0] = x;
+      for (int y = 0; y < shd->grid_size[1]; y++) {
+        mat[3][1] = y;
+        DRW_shgroup_call_obmat(grp, DRW_cache_quad_wires_get(), mat);
+      }
+    }
+  }
 }
 
 void OVERLAY_grid_draw(OVERLAY_Data *vedata)

source/blender/draw/engines/overlay/overlay_private.h

@@ -127,7 +127,7 @@ typedef struct OVERLAY_PassList {
 typedef struct OVERLAY_ShadingData {
   /** Grid */
   float grid_axes[3], grid_distance;
-  float zplane_axes[3], grid_mesh_size;
+  float zplane_axes[3], grid_size[3];
   float grid_steps[8];
   float inv_viewport_size[2];
   float grid_line_size;

source/blender/draw/engines/overlay/shaders/grid_frag.glsl

@@ -10,7 +10,7 @@ out vec4 FragColor;
 
 uniform vec3 planeAxes;
 uniform float gridDistance;
-uniform float meshSize;
+uniform vec3 gridSize;
 uniform float lineKernel = 0.0;
 uniform sampler2D depthBuffer;
 
@@ -73,7 +73,7 @@ vec3 get_axes(vec3 co, vec3 fwidthCos, float line_size)
 
 void main()
 {
-  vec3 wPos = local_pos * meshSize;
+  vec3 wPos = local_pos * gridSize;
   vec3 dFdxPos = dFdx(wPos);
   vec3 dFdyPos = dFdy(wPos);
   vec3 fwidthPos = abs(dFdxPos) + abs(dFdyPos);

source/blender/draw/engines/overlay/shaders/grid_vert.glsl

@@ -3,7 +3,7 @@
  * Clément Foucault */
 
 uniform vec3 planeAxes;
-uniform float meshSize;
+uniform vec3 gridSize;
 
 uniform int gridFlag;
 
@@ -37,7 +37,7 @@ void main()
 
   local_pos = vert_pos;
 
-  vec3 real_pos = cameraPos * planeAxes + vert_pos * meshSize;
+  vec3 real_pos = cameraPos * planeAxes + vert_pos * gridSize;
 
   /* Used for additional Z axis */
   if ((gridFlag & CLIP_Z_POS) != 0) {