13 files changed, 140 insertions, 106 deletions
diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt
index f4e57d9521b..3c25252efe8 100644
--- a/source/blender/draw/CMakeLists.txt
+++ b/source/blender/draw/CMakeLists.txt
@@ -518,8 +518,10 @@ set(GLSL_SRC
   engines/overlay/shaders/wireframe_frag.glsl
   engines/overlay/shaders/xray_fade_frag.glsl
 
-  engines/image/shaders/image_engine_frag.glsl
-  engines/image/shaders/image_engine_vert.glsl
+  engines/image/shaders/image_engine_color_frag.glsl
+  engines/image/shaders/image_engine_color_vert.glsl
+  engines/image/shaders/image_engine_depth_frag.glsl
+  engines/image/shaders/image_engine_depth_vert.glsl
 )
 
 set(GLSL_C)
diff --git a/source/blender/draw/engines/image/image_drawing_mode.hh b/source/blender/draw/engines/image/image_drawing_mode.hh
index f501bc78b11..d5a4a317a22 100644
--- a/source/blender/draw/engines/image/image_drawing_mode.hh
+++ b/source/blender/draw/engines/image/image_drawing_mode.hh
@@ -26,6 +26,8 @@
 
 #include "IMB_imbuf_types.h"
 
+#include "BLI_math_vec_types.hh"
+
 #include "image_batches.hh"
 #include "image_private.hh"
 #include "image_wrappers.hh"
@@ -80,13 +82,19 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
  private:
   DRWPass *create_image_pass() const
   {
-    /* Write depth is needed for background overlay rendering. Near depth is used for
-     * transparency checker and Far depth is used for indicating the image size. */
-    DRWState state = static_cast<DRWState>(DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH |
-                                           DRW_STATE_DEPTH_ALWAYS | DRW_STATE_BLEND_ALPHA_PREMUL);
+    DRWState state = static_cast<DRWState>(DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_ALWAYS |
+                                           DRW_STATE_BLEND_ALPHA_PREMUL);
     return DRW_pass_create("Image", state);
   }
 
+  DRWPass *create_depth_pass() const
+  {
+    /* Depth is needed for background overlay rendering. Near depth is used for
+     * transparency checker and Far depth is used for indicating the image size. */
+    DRWState state = static_cast<DRWState>(DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL);
+    return DRW_pass_create("Depth", state);
+  }
+
   void add_shgroups(const IMAGE_InstanceData *instance_data) const
   {
     const ShaderParameters &sh_params = instance_data->sh_params;
@@ -97,7 +105,6 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
     DRW_shgroup_uniform_vec4_copy(shgrp, "shuffle", sh_params.shuffle);
     DRW_shgroup_uniform_int_copy(shgrp, "drawFlags", sh_params.flags);
     DRW_shgroup_uniform_bool_copy(shgrp, "imgPremultiplied", sh_params.use_premul_alpha);
-    DRW_shgroup_uniform_vec2_copy(shgrp, "maxUv", instance_data->max_uv);
     float image_mat[4][4];
     unit_m4(image_mat);
     for (int i = 0; i < SCREEN_SPACE_DRAWING_MODE_TEXTURE_LEN; i++) {
@@ -113,6 +120,37 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
   }
 
   /**
+   * \brief add depth drawing calls.
+   *
+   * The depth is used to identify if the tile exist or transparent.
+   */
+  void add_depth_shgroups(IMAGE_InstanceData &instance_data,
+                          Image *image,
+                          ImageUser *UNUSED(image_user)) const
+  {
+    GPUShader *shader = IMAGE_shader_depth_get();
+    DRWShadingGroup *shgrp = DRW_shgroup_create(shader, instance_data.passes.depth_pass);
+    float image_mat[4][4];
+    unit_m4(image_mat);
+    for (int i = 0; i < SCREEN_SPACE_DRAWING_MODE_TEXTURE_LEN; i++) {
+      const TextureInfo &info = instance_data.texture_infos[i];
+      if (!info.visible) {
+        continue;
+      }
+
+      LISTBASE_FOREACH (ImageTile *, image_tile_ptr, &image->tiles) {
+        DRWShadingGroup *shsub = DRW_shgroup_create_sub(shgrp);
+        const ImageTileWrapper image_tile(image_tile_ptr);
+        const int tile_x = image_tile.get_tile_x_offset();
+        const int tile_y = image_tile.get_tile_y_offset();
+        float4 min_max_uv(tile_x, tile_y, tile_x + 1, tile_y + 1);
+        DRW_shgroup_uniform_vec4_copy(shsub, "min_max_uv", min_max_uv);
+        DRW_shgroup_call_obmat(shsub, info.batch, image_mat);
+      }
+    }
+  }
+
+  /**
    * \brief Update GPUTextures for drawing the image.
    *
    * GPUTextures that are marked dirty are rebuild. GPUTextures that aren't marked dirty are
@@ -367,6 +405,7 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
   {
     IMAGE_InstanceData *instance_data = vedata->instance_data;
     instance_data->passes.image_pass = create_image_pass();
+    instance_data->passes.depth_pass = create_depth_pass();
   }
 
   void cache_image(IMAGE_Data *vedata, Image *image, ImageUser *iuser) const override
@@ -376,7 +415,6 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
     TextureMethod method(instance_data);
 
     instance_data->partial_update.ensure_image(image);
-    instance_data->max_uv_update();
     instance_data->clear_dirty_flag();
 
     // Step: Find out which screen space textures are needed to draw on the screen. Remove the
@@ -391,6 +429,7 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
 
     // Step: Add the GPU textures to the shgroup.
     instance_data->update_batches();
+    add_depth_shgroups(*instance_data, image, iuser);
     add_shgroups(instance_data);
   }
 
@@ -408,6 +447,7 @@ template<typename TextureMethod> class ScreenSpaceDrawingMode : public AbstractD
     GPU_framebuffer_clear_color_depth(dfbl->default_fb, clear_col, 1.0);
 
     DRW_view_set_active(instance_data->view);
+    DRW_draw_pass(instance_data->passes.depth_pass);
     DRW_draw_pass(instance_data->passes.image_pass);
     DRW_view_set_active(nullptr);
   }
diff --git a/source/blender/draw/engines/image/image_engine.cc b/source/blender/draw/engines/image/image_engine.cc
index 840d4840f1b..201733f41a7 100644
--- a/source/blender/draw/engines/image/image_engine.cc
+++ b/source/blender/draw/engines/image/image_engine.cc
@@ -145,7 +145,6 @@ class ImageEngine {
 
 static void IMAGE_engine_init(void *ved)
 {
-  IMAGE_shader_library_ensure();
   IMAGE_Data *vedata = (IMAGE_Data *)ved;
   if (vedata->instance_data == nullptr) {
     vedata->instance_data = MEM_new<IMAGE_InstanceData>(__func__);
diff --git a/source/blender/draw/engines/image/image_instance_data.hh b/source/blender/draw/engines/image/image_instance_data.hh
index 7fb0a6ca3eb..1a7a20b8b9a 100644
--- a/source/blender/draw/engines/image/image_instance_data.hh
+++ b/source/blender/draw/engines/image/image_instance_data.hh
@@ -57,29 +57,14 @@ struct IMAGE_InstanceData {
 
   struct {
     DRWPass *image_pass;
+    DRWPass *depth_pass;
   } passes;
 
   /** \brief Transform matrix to convert a normalized screen space coordinates to texture space. */
   float ss_to_texture[4][4];
   TextureInfo texture_infos[SCREEN_SPACE_DRAWING_MODE_TEXTURE_LEN];
 
-  /**
-   * \brief Maximum uv's that are on the border of the image.
-   *
-   * Larger UV coordinates would be drawn as a border. */
-  float max_uv[2];
-
  public:
-  void max_uv_update()
-  {
-    copy_v2_fl2(max_uv, 1.0f, 1.0);
-    LISTBASE_FOREACH (ImageTile *, image_tile_ptr, &image->tiles) {
-      ImageTileWrapper image_tile(image_tile_ptr);
-      max_uv[0] = max_ii(max_uv[0], image_tile.get_tile_x_offset() + 1);
-      max_uv[1] = max_ii(max_uv[1], image_tile.get_tile_y_offset() + 1);
-    }
-  }
-
   void clear_dirty_flag()
   {
     reset_dirty_flag(false);
diff --git a/source/blender/draw/engines/image/image_private.hh b/source/blender/draw/engines/image/image_private.hh
index 6d665db4c41..d8f8adb7e84 100644
--- a/source/blender/draw/engines/image/image_private.hh
+++ b/source/blender/draw/engines/image/image_private.hh
@@ -72,7 +72,7 @@ class AbstractDrawingMode {
 
 /* image_shader.c */
 GPUShader *IMAGE_shader_image_get();
-void IMAGE_shader_library_ensure();
+GPUShader *IMAGE_shader_depth_get();
 void IMAGE_shader_free();
 
 }  // namespace blender::draw::image_engine
diff --git a/source/blender/draw/engines/image/image_shader.cc b/source/blender/draw/engines/image/image_shader.cc
index e3cb60c5511..952843d7dd7 100644
--- a/source/blender/draw/engines/image/image_shader.cc
+++ b/source/blender/draw/engines/image/image_shader.cc
@@ -29,44 +29,33 @@
 #include "image_engine.h"
 #include "image_private.hh"
 
-extern "C" {
-extern char datatoc_common_colormanagement_lib_glsl[];
-extern char datatoc_common_globals_lib_glsl[];
-extern char datatoc_common_view_lib_glsl[];
-
-extern char datatoc_engine_image_frag_glsl[];
-extern char datatoc_engine_image_vert_glsl[];
-}
-
 namespace blender::draw::image_engine {
 
 struct IMAGE_Shaders {
   GPUShader *image_sh;
+  GPUShader *depth_sh;
 };
 
 static struct {
   IMAGE_Shaders shaders;
-  DRWShaderLibrary *lib;
 } e_data = {{nullptr}}; /* Engine data */
 
-void IMAGE_shader_library_ensure()
+GPUShader *IMAGE_shader_image_get()
 {
-  if (e_data.lib == nullptr) {
-    e_data.lib = DRW_shader_library_create();
-    /* NOTE: These need to be ordered by dependencies. */
-    DRW_SHADER_LIB_ADD(e_data.lib, common_colormanagement_lib);
-    DRW_SHADER_LIB_ADD(e_data.lib, common_globals_lib);
-    DRW_SHADER_LIB_ADD(e_data.lib, common_view_lib);
+  IMAGE_Shaders *sh_data = &e_data.shaders;
+  if (sh_data->image_sh == nullptr) {
+    sh_data->image_sh = GPU_shader_create_from_info_name("image_engine_color_shader");
   }
+  return sh_data->image_sh;
 }
 
-GPUShader *IMAGE_shader_image_get()
+GPUShader *IMAGE_shader_depth_get()
 {
   IMAGE_Shaders *sh_data = &e_data.shaders;
-  if (sh_data->image_sh == nullptr) {
-    sh_data->image_sh = GPU_shader_create_from_info_name("image_engine_shader");
+  if (sh_data->depth_sh == nullptr) {
+    sh_data->depth_sh = GPU_shader_create_from_info_name("image_engine_depth_shader");
   }
-  return sh_data->image_sh;
+  return sh_data->depth_sh;
 }
 
 void IMAGE_shader_free()
@@ -75,8 +64,6 @@ void IMAGE_shader_free()
   for (int i = 0; i < (sizeof(IMAGE_Shaders) / sizeof(GPUShader *)); i++) {
     DRW_SHADER_FREE_SAFE(sh_data_as_array[i]);
   }
-
-  DRW_SHADER_LIB_FREE_SAFE(e_data.lib);
 }
 
 }  // namespace blender::draw::image_engine
diff --git a/source/blender/draw/engines/image/shaders/image_engine_color_frag.glsl b/source/blender/draw/engines/image/shaders/image_engine_color_frag.glsl
new file mode 100644
index 00000000000..fbb624e54ba
--- /dev/null
+++ b/source/blender/draw/engines/image/shaders/image_engine_color_frag.glsl
@@ -0,0 +1,33 @@
+#pragma BLENDER_REQUIRE(common_colormanagement_lib.glsl)
+
+/* Keep in sync with image_engine.c */
+#define IMAGE_DRAW_FLAG_SHOW_ALPHA (1 << 0)
+#define IMAGE_DRAW_FLAG_APPLY_ALPHA (1 << 1)
+#define IMAGE_DRAW_FLAG_SHUFFLING (1 << 2)
+#define IMAGE_DRAW_FLAG_DEPTH (1 << 3)
+
+#define FAR_DISTANCE farNearDistances.x
+#define NEAR_DISTANCE farNearDistances.y
+
+void main()
+{
+  ivec2 uvs_clamped = ivec2(uv_screen);
+  vec4 tex_color = texelFetch(imageTexture, uvs_clamped, 0);
+
+  if ((drawFlags & IMAGE_DRAW_FLAG_APPLY_ALPHA) != 0) {
+    if (!imgPremultiplied) {
+      tex_color.rgb *= tex_color.a;
+    }
+  }
+  if ((drawFlags & IMAGE_DRAW_FLAG_DEPTH) != 0) {
+    tex_color = smoothstep(FAR_DISTANCE, NEAR_DISTANCE, tex_color);
+  }
+
+  if ((drawFlags & IMAGE_DRAW_FLAG_SHUFFLING) != 0) {
+    tex_color = vec4(dot(tex_color, shuffle));
+  }
+  if ((drawFlags & IMAGE_DRAW_FLAG_SHOW_ALPHA) == 0) {
+    tex_color.a = 1.0;
+  }
+  fragColor = tex_color;
+}
diff --git a/source/blender/draw/engines/image/shaders/image_engine_vert.glsl b/source/blender/draw/engines/image/shaders/image_engine_color_vert.glsl
index deefab655d2..fb72a132613 100644
--- a/source/blender/draw/engines/image/shaders/image_engine_vert.glsl
+++ b/source/blender/draw/engines/image/shaders/image_engine_color_vert.glsl
@@ -4,7 +4,6 @@ void main()
 {
   vec3 image_pos = vec3(pos, 0.0);
   uv_screen = image_pos.xy;
-  uv_image = uv;
 
   vec3 world_pos = point_object_to_world(image_pos);
   vec4 position = point_world_to_ndc(world_pos);
diff --git a/source/blender/draw/engines/image/shaders/image_engine_depth_frag.glsl b/source/blender/draw/engines/image/shaders/image_engine_depth_frag.glsl
new file mode 100644
index 00000000000..88610fb97fd
--- /dev/null
+++ b/source/blender/draw/engines/image/shaders/image_engine_depth_frag.glsl
@@ -0,0 +1,16 @@
+#pragma BLENDER_REQUIRE(common_colormanagement_lib.glsl)
+
+#define Z_DEPTH_BORDER 1.0
+#define Z_DEPTH_IMAGE 0.75
+
+bool is_border(vec2 uv)
+{
+  return (uv.x < min_max_uv.x || uv.y < min_max_uv.y || uv.x >= min_max_uv.z ||
+          uv.y >= min_max_uv.w);
+}
+
+void main()
+{
+  bool border = is_border(uv_image);
+  gl_FragDepth = border ? Z_DEPTH_BORDER : Z_DEPTH_IMAGE;
+}
diff --git a/source/blender/draw/engines/image/shaders/image_engine_depth_vert.glsl b/source/blender/draw/engines/image/shaders/image_engine_depth_vert.glsl
new file mode 100644
index 00000000000..3181a85ff55
--- /dev/null
+++ b/source/blender/draw/engines/image/shaders/image_engine_depth_vert.glsl
@@ -0,0 +1,11 @@
+#pragma BLENDER_REQUIRE(common_view_lib.glsl)
+
+void main()
+{
+  vec3 image_pos = vec3(pos, 0.0);
+  uv_image = uv;
+
+  vec3 world_pos = point_object_to_world(image_pos);
+  vec4 position = point_world_to_ndc(world_pos);
+  gl_Position = position;
+}
diff --git a/source/blender/draw/engines/image/shaders/image_engine_frag.glsl b/source/blender/draw/engines/image/shaders/image_engine_frag.glsl
deleted file mode 100644
index b0ac7af457f..00000000000
--- a/source/blender/draw/engines/image/shaders/image_engine_frag.glsl
+++ /dev/null
@@ -1,45 +0,0 @@
-#pragma BLENDER_REQUIRE(common_colormanagement_lib.glsl)
-
-/* Keep in sync with image_engine.c */
-#define IMAGE_DRAW_FLAG_SHOW_ALPHA (1 << 0)
-#define IMAGE_DRAW_FLAG_APPLY_ALPHA (1 << 1)
-#define IMAGE_DRAW_FLAG_SHUFFLING (1 << 2)
-#define IMAGE_DRAW_FLAG_DEPTH (1 << 3)
-
-#define Z_DEPTH_BORDER 1.0
-#define Z_DEPTH_IMAGE 0.75
-
-#define FAR_DISTANCE farNearDistances.x
-#define NEAR_DISTANCE farNearDistances.y
-
-bool is_border(vec2 uv)
-{
-  return (uv.x < 0.0 || uv.y < 0.0 || uv.x > maxUv.x || uv.y > maxUv.y);
-}
-
-void main()
-{
-  ivec2 uvs_clamped = ivec2(uv_screen);
-  vec4 tex_color = texelFetch(imageTexture, uvs_clamped, 0);
-
-  bool border = is_border(uv_image);
-  if (!border) {
-    if ((drawFlags & IMAGE_DRAW_FLAG_APPLY_ALPHA) != 0) {
-      if (!imgPremultiplied) {
-        tex_color.rgb *= tex_color.a;
-      }
-    }
-    if ((drawFlags & IMAGE_DRAW_FLAG_DEPTH) != 0) {
-      tex_color = smoothstep(FAR_DISTANCE, NEAR_DISTANCE, tex_color);
-    }
-
-    if ((drawFlags & IMAGE_DRAW_FLAG_SHUFFLING) != 0) {
-      tex_color = vec4(dot(tex_color, shuffle));
-    }
-    if ((drawFlags & IMAGE_DRAW_FLAG_SHOW_ALPHA) == 0) {
-      tex_color.a = 1.0;
-    }
-  }
-  fragColor = tex_color;
-  gl_FragDepth = border ? Z_DEPTH_BORDER : Z_DEPTH_IMAGE;
-}
diff --git a/source/blender/draw/engines/image/shaders/infos/engine_image_info.hh b/source/blender/draw/engines/image/shaders/infos/engine_image_info.hh
index 1dd20a9a95b..86a79d13e40 100644
--- a/source/blender/draw/engines/image/shaders/infos/engine_image_info.hh
+++ b/source/blender/draw/engines/image/shaders/infos/engine_image_info.hh
@@ -1,21 +1,29 @@
 #include "gpu_shader_create_info.hh"
 
-GPU_SHADER_INTERFACE_INFO(image_engine_iface, "")
-    .smooth(Type::VEC2, "uv_screen")
-    .smooth(Type::VEC2, "uv_image");
+GPU_SHADER_INTERFACE_INFO(image_engine_color_iface, "").smooth(Type::VEC2, "uv_screen");
 
-GPU_SHADER_CREATE_INFO(image_engine_shader)
+GPU_SHADER_CREATE_INFO(image_engine_color_shader)
     .vertex_in(0, Type::VEC2, "pos")
-    .vertex_in(1, Type::VEC2, "uv")
-    .vertex_out(image_engine_iface)
+    .vertex_out(image_engine_color_iface)
     .fragment_out(0, Type::VEC4, "fragColor")
     .push_constant(Type::VEC4, "shuffle")
-    .push_constant(Type::VEC2, "maxUv")
     .push_constant(Type::VEC2, "farNearDistances")
     .push_constant(Type::INT, "drawFlags")
     .push_constant(Type::BOOL, "imgPremultiplied")
     .sampler(0, ImageType::FLOAT_2D, "imageTexture")
-    .vertex_source("image_engine_vert.glsl")
-    .fragment_source("image_engine_frag.glsl")
+    .vertex_source("image_engine_color_vert.glsl")
+    .fragment_source("image_engine_color_frag.glsl")
+    .additional_info("draw_modelmat")
+    .do_static_compilation(true);
+
+GPU_SHADER_INTERFACE_INFO(image_engine_depth_iface, "").smooth(Type::VEC2, "uv_image");
+
+GPU_SHADER_CREATE_INFO(image_engine_depth_shader)
+    .vertex_in(0, Type::VEC2, "pos")
+    .vertex_in(1, Type::VEC2, "uv")
+    .vertex_out(image_engine_depth_iface)
+    .push_constant(Type::VEC4, "min_max_uv")
+    .vertex_source("image_engine_depth_vert.glsl")
+    .fragment_source("image_engine_depth_frag.glsl")
     .additional_info("draw_modelmat")
     .do_static_compilation(true);
diff --git a/source/blender/draw/tests/shaders_test.cc b/source/blender/draw/tests/shaders_test.cc
index b97298cbe95..80f87eea7ca 100644
--- a/source/blender/draw/tests/shaders_test.cc
+++ b/source/blender/draw/tests/shaders_test.cc
@@ -183,9 +183,8 @@ DRAW_TEST(gpencil_glsl_shaders)
 
 static void test_image_glsl_shaders()
 {
-  IMAGE_shader_library_ensure();
-
   EXPECT_NE(IMAGE_shader_image_get(), nullptr);
+  EXPECT_NE(IMAGE_shader_depth_get(), nullptr);
 
   IMAGE_shader_free();
 }