GPU: remove 'GPU_SHADER_2D_FLAT_COLOR'

The only real difference between `GPU_SHADER_2D_FLAT_COLOR` and
`GPU_SHADER_3D_FLAT_COLOR` is that in the vertex shader the 2D
version uses `vec4(pos, 0.0, 1.0)` and the 3D version uses
`vec4(pos, 1.0)`.

But VBOs with 2D attributes work perfectly in shaders that use 3D
attributes. Components not specified are filled with components from
`vec4(0.0, 0.0, 0.0, 1.0)`.

So there is no real benefit to having two different shader versions.

This will simplify porting shaders to python as it will not be
necessary to use a 3D and a 2D version of the shaders.

In python the new name for '2D_FLAT_COLOR'' and '3D_FLAT_COLOR'
is 'FLAT_COLOR', but the old names still work for backward
compatibility.

16 files changed, 14 insertions, 57 deletions

diff --git a/source/blender/draw/intern/draw_view.c b/source/blender/draw/intern/draw_view.c
index 817f97cbea4..35ff8891a0f 100644
--- a/source/blender/draw/intern/draw_view.c
+++ b/source/blender/draw/intern/draw_view.c
@@ -175,7 +175,7 @@ void DRW_draw_cursor(void)
       GPU_matrix_scale_2f(U.widget_unit, U.widget_unit);
 
       GPUBatch *cursor_batch = DRW_cache_cursor_get(is_aligned);
-      GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_2D_FLAT_COLOR);
+      GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_3D_FLAT_COLOR);
       GPU_batch_set_shader(cursor_batch, shader);
 
       GPU_batch_draw(cursor_batch);
@@ -241,7 +241,7 @@ void DRW_draw_cursor_2d_ex(const ARegion *region, const float cursor[2])
 
   GPUBatch *cursor_batch = DRW_cache_cursor_get(true);
 
-  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_2D_FLAT_COLOR);
+  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_3D_FLAT_COLOR);
   GPU_batch_set_shader(cursor_batch, shader);
 
   GPU_batch_draw(cursor_batch);
diff --git a/source/blender/editors/gizmo_library/gizmo_types/cage2d_gizmo.c b/source/blender/editors/gizmo_library/gizmo_types/cage2d_gizmo.c
index 1c8985b1ad7..600abaf3737 100644
--- a/source/blender/editors/gizmo_library/gizmo_types/cage2d_gizmo.c
+++ b/source/blender/editors/gizmo_library/gizmo_types/cage2d_gizmo.c
@@ -388,7 +388,7 @@ static void cage2d_draw_box_interaction(const float color[4],
       .pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT),
       .col = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 3, GPU_FETCH_FLOAT),
   };
-  immBindBuiltinProgram(is_solid ? GPU_SHADER_2D_FLAT_COLOR : GPU_SHADER_3D_POLYLINE_FLAT_COLOR);
+  immBindBuiltinProgram(is_solid ? GPU_SHADER_3D_FLAT_COLOR : GPU_SHADER_3D_POLYLINE_FLAT_COLOR);
 
   {
     if (is_solid) {
diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index 7d1b6482110..4dae8222b14 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -1698,7 +1698,7 @@ void ui_draw_but_CURVE(ARegion *region, uiBut *but, const uiWidgetColors *wcol,
   format = immVertexFormat();
   pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   const uint col = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
 
   /* Calculate vertex colors based on text theme. */
   float color_vert[4], color_vert_select[4];
@@ -1948,7 +1948,7 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
   format = immVertexFormat();
   pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   const uint col = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
 
   /* Calculate vertex colors based on text theme. */
   float color_vert[4], color_vert_select[4], color_sample[4];
@@ -2152,7 +2152,7 @@ void ui_draw_but_TRACKPREVIEW(ARegion *UNUSED(region),
       GPUVertFormat *format = immVertexFormat();
       const uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
       const uint col = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-      immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+      immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
 
       UI_GetThemeColor4fv(TH_SEL_MARKER, col_sel);
       UI_GetThemeColor4fv(TH_MARKER_OUTLINE, col_outline);
diff --git a/source/blender/editors/interface/interface_panel.cc b/source/blender/editors/interface/interface_panel.cc
index 38ed126880e..745a2201dc1 100644
--- a/source/blender/editors/interface/interface_panel.cc
+++ b/source/blender/editors/interface/interface_panel.cc
@@ -1160,7 +1160,7 @@ static void panel_draw_aligned_widgets(const uiStyle *style,
 
     GPUBatch *batch = GPU_batch_preset_panel_drag_widget(
         U.pixelsize, color_high, color_dark, drag_widget_size);
-    GPU_batch_program_set_builtin(batch, GPU_SHADER_2D_FLAT_COLOR);
+    GPU_batch_program_set_builtin(batch, GPU_SHADER_3D_FLAT_COLOR);
     GPU_batch_draw(batch);
     GPU_matrix_pop();
   }
diff --git a/source/blender/editors/interface/view2d.cc b/source/blender/editors/interface/view2d.cc
index 1bf7e25b154..c2ca0ac8c72 100644
--- a/source/blender/editors/interface/view2d.cc
+++ b/source/blender/editors/interface/view2d.cc
@@ -1136,7 +1136,7 @@ void UI_view2d_multi_grid_draw(
 
   GPU_line_width(1.0f);
 
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
   immBeginAtMost(GPU_PRIM_LINES, vertex_count);
 
   for (int level = 0; level < totlevels; level++) {
@@ -1234,7 +1234,7 @@ void UI_view2d_dot_grid_draw(const View2D *v2d,
   GPUVertFormat *format = immVertexFormat();
   const uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   const uint color_id = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
 
   /* Scaling the dots fully with the zoom looks too busy, but a bit of size variation is nice. */
   const float min_point_size = 2.0f * UI_DPI_FAC;
diff --git a/source/blender/editors/screen/area.c b/source/blender/editors/screen/area.c
index b41eaa26edf..dc3aaea5e49 100644
--- a/source/blender/editors/screen/area.c
+++ b/source/blender/editors/screen/area.c
@@ -3664,7 +3664,7 @@ void ED_region_grid_draw(ARegion *region, float zoomx, float zoomy, float x0, fl
     pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
     uint color = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
 
-    immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+    immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
     immBegin(GPU_PRIM_LINES, 4 * count_fine + 4 * count_large);
 
     float theme_color[3];
diff --git a/source/blender/editors/space_file/file_draw.c b/source/blender/editors/space_file/file_draw.c
index 9b9b7199c99..8ebda7ef98e 100644
--- a/source/blender/editors/space_file/file_draw.c
+++ b/source/blender/editors/space_file/file_draw.c
@@ -631,7 +631,7 @@ static void draw_dividers(FileLayout *layout, View2D *v2d)
     uint color = GPU_vertformat_attr_add(
         format, "color", GPU_COMP_U8, 3, GPU_FETCH_INT_TO_FLOAT_UNIT);
 
-    immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+    immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
     immBegin(GPU_PRIM_LINES, vertex_len);
 
     sx = (int)v2d->tot.xmin;
diff --git a/source/blender/editors/space_graph/graph_draw.c b/source/blender/editors/space_graph/graph_draw.c
index 6ee1e6f021a..659cba0587a 100644
--- a/source/blender/editors/space_graph/graph_draw.c
+++ b/source/blender/editors/space_graph/graph_draw.c
@@ -408,7 +408,7 @@ static void draw_fcurve_handles(SpaceGraph *sipo, FCurve *fcu)
   uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   uint color = GPU_vertformat_attr_add(
       format, "color", GPU_COMP_U8, 4, GPU_FETCH_INT_TO_FLOAT_UNIT);
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
   if ((sipo->flag & SIPO_BEAUTYDRAW_OFF) == 0) {
     GPU_line_smooth(true);
   }
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 8ab89a3368d..929217fa10e 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -311,7 +311,7 @@ static size_t draw_waveform_segment(WaveVizData *waveform_data, bool use_rms)
   GPUPrimType prim_type = waveform_data->draw_line ? GPU_PRIM_LINE_STRIP : GPU_PRIM_TRI_STRIP;
   uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   uint col = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
   immBegin(prim_type, vertex_count);
 
   while (vertices_done < vertex_count && !waveform_data->final_sample) {
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index a91a1277899..0af8994ea78 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -982,7 +982,7 @@ static void draw_view_axis(RegionView3D *rv3d, const rcti *rect)
   uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   uint col = GPU_vertformat_attr_add(format, "color", GPU_COMP_U8, 4, GPU_FETCH_INT_TO_FLOAT_UNIT);
 
-  immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
+  immBindBuiltinProgram(GPU_SHADER_3D_FLAT_COLOR);
   immBegin(GPU_PRIM_LINES, 6);
 
   for (int axis_i = 0; axis_i < 3; axis_i++) {
diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index 6c7e03b0994..d1b0e227506 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -272,7 +272,6 @@ set(GLSL_SRC
   shaders/gpu_shader_2D_widget_shadow_frag.glsl
   shaders/gpu_shader_2D_nodelink_frag.glsl
   shaders/gpu_shader_2D_nodelink_vert.glsl
-  shaders/gpu_shader_2D_flat_color_vert.glsl
   shaders/gpu_shader_2D_line_dashed_uniform_color_vert.glsl
   shaders/gpu_shader_2D_line_dashed_frag.glsl
   shaders/gpu_shader_2D_smooth_color_vert.glsl
@@ -577,7 +576,6 @@ set(SRC_SHADER_CREATE_INFOS
   shaders/infos/gpu_shader_2D_area_borders_info.hh
   shaders/infos/gpu_shader_2D_checker_info.hh
   shaders/infos/gpu_shader_2D_diag_stripes_info.hh
-  shaders/infos/gpu_shader_2D_flat_color_info.hh
   shaders/infos/gpu_shader_2D_image_color_info.hh
   shaders/infos/gpu_shader_2D_image_desaturate_color_info.hh
   shaders/infos/gpu_shader_2D_image_info.hh
diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index dcf63507f89..65a628bcd76 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -207,13 +207,6 @@ typedef enum eGPUBuiltinShader {
   GPU_SHADER_KEYFRAME_SHAPE,
   GPU_SHADER_SIMPLE_LIGHTING,
   /**
-   * Take a 2D position and color for each vertex without color interpolation.
-   *
-   * \param color: in vec4
-   * \param pos: in vec2
-   */
-  GPU_SHADER_2D_FLAT_COLOR,
-  /**
    * Take a 2D position and color for each vertex with linear interpolation in window space.
    *
    * \param color: in vec4
diff --git a/source/blender/gpu/intern/gpu_immediate.cc b/source/blender/gpu/intern/gpu_immediate.cc
index be1972beab6..8574e886cd0 100644
--- a/source/blender/gpu/intern/gpu_immediate.cc
+++ b/source/blender/gpu/intern/gpu_immediate.cc
@@ -134,7 +134,6 @@ static void wide_line_workaround_start(GPUPrimType prim_type)
     case GPU_SHADER_3D_UNIFORM_COLOR:
       polyline_sh = GPU_SHADER_3D_POLYLINE_UNIFORM_COLOR;
       break;
-    case GPU_SHADER_2D_FLAT_COLOR:
     case GPU_SHADER_3D_FLAT_COLOR:
       polyline_sh = GPU_SHADER_3D_POLYLINE_FLAT_COLOR;
       break;
diff --git a/source/blender/gpu/intern/gpu_shader_builtin.c b/source/blender/gpu/intern/gpu_shader_builtin.c
index 502363d97db..4776a8b9b12 100644
--- a/source/blender/gpu/intern/gpu_shader_builtin.c
+++ b/source/blender/gpu/intern/gpu_shader_builtin.c
@@ -25,7 +25,6 @@ extern char datatoc_gpu_shader_flat_id_frag_glsl[];
 extern char datatoc_gpu_shader_2D_area_borders_vert_glsl[];
 extern char datatoc_gpu_shader_2D_area_borders_frag_glsl[];
 extern char datatoc_gpu_shader_2D_vert_glsl[];
-extern char datatoc_gpu_shader_2D_flat_color_vert_glsl[];
 extern char datatoc_gpu_shader_2D_smooth_color_uniform_alpha_vert_glsl[];
 extern char datatoc_gpu_shader_2D_smooth_color_vert_glsl[];
 extern char datatoc_gpu_shader_2D_smooth_color_frag_glsl[];
@@ -156,11 +155,6 @@ static const GPUShaderStages builtin_shader_stages[GPU_SHADER_BUILTIN_LEN] = {
             .create_info = "gpu_shader_2D_diag_stripes",
         },
 
-    [GPU_SHADER_2D_FLAT_COLOR] =
-        {
-            .name = "GPU_SHADER_2D_FLAT_COLOR",
-            .create_info = "gpu_shader_2D_flat_color",
-        },
     [GPU_SHADER_2D_SMOOTH_COLOR] =
         {
             .name = "GPU_SHADER_2D_SMOOTH_COLOR",
diff --git a/source/blender/gpu/shaders/gpu_shader_2D_flat_color_vert.glsl b/source/blender/gpu/shaders/gpu_shader_2D_flat_color_vert.glsl
deleted file mode 100644
index cf948bb2533..00000000000
--- a/source/blender/gpu/shaders/gpu_shader_2D_flat_color_vert.glsl
+++ /dev/null
@@ -1,6 +0,0 @@
-
-void main()
-{
-  gl_Position = ModelViewProjectionMatrix * vec4(pos, 0.0, 1.0);
-  finalColor = color;
-}
diff --git a/source/blender/gpu/shaders/infos/gpu_shader_2D_flat_color_info.hh b/source/blender/gpu/shaders/infos/gpu_shader_2D_flat_color_info.hh
deleted file mode 100644
index 24a06a37a44..00000000000
--- a/source/blender/gpu/shaders/infos/gpu_shader_2D_flat_color_info.hh
+++ /dev/null
@@ -1,21 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later
- * Copyright 2022 Blender Foundation. All rights reserved. */
-
-/** \file
- * \ingroup gpu
- */
-
-#include "gpu_shader_create_info.hh"
-
-#include "gpu_interface_info.hh"
-
-GPU_SHADER_CREATE_INFO(gpu_shader_2D_flat_color)
-    .vertex_in(0, Type::VEC2, "pos")
-    .vertex_in(1, Type::VEC4, "color")
-    .vertex_out(flat_color_iface)
-    .fragment_out(0, Type::VEC4, "fragColor")
-    .push_constant(Type::MAT4, "ModelViewProjectionMatrix")
-    .vertex_source("gpu_shader_2D_flat_color_vert.glsl")
-    .fragment_source("gpu_shader_flat_color_frag.glsl")
-    .additional_info("gpu_srgb_to_framebuffer_space")
-    .do_static_compilation(true);