From 4537d98d46005cb68f7c00e00154cf1aaeaa68c6 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Tue, 2 Mar 2021 15:03:16 +0100
Subject: [PATCH] Backends: DX9: Fix to support colored glyphs, using newly
 introduced 'TexPixelsUseColors' info. (#3369, #3844)

---
 backends/imgui_impl_dx9.cpp | 19 ++++++++++++++-----
 docs/CHANGELOG.txt          |  1 +
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/backends/imgui_impl_dx9.cpp b/backends/imgui_impl_dx9.cpp
index 7e851ec7..3fe0fe3e 100644
--- a/backends/imgui_impl_dx9.cpp
+++ b/backends/imgui_impl_dx9.cpp
@@ -45,6 +45,12 @@ struct CUSTOMVERTEX
 };
 #define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE|D3DFVF_TEX1)
 
+#ifdef IMGUI_USE_BGRA_PACKED_COLOR
+#define IMGUI_COL_TO_DX9_ARGB(_COL)     (_COL)
+#else
+#define IMGUI_COL_TO_DX9_ARGB(_COL)     (((_COL) & 0xFF00FF00) | (((_COL) & 0xFF0000) >> 16) | (((_COL) & 0xFF) << 16))
+#endif
+
 static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
 {
     // Setup viewport
@@ -157,11 +163,7 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
             vtx_dst->pos[0] = vtx_src->pos.x;
             vtx_dst->pos[1] = vtx_src->pos.y;
             vtx_dst->pos[2] = 0.0f;
-#ifdef IMGUI_USE_BGRA_PACKED_COLOR
-            vtx_dst->col = vtx_src->col;
-#else
-            vtx_dst->col = (vtx_src->col & 0xFF00FF00) | ((vtx_src->col & 0xFF0000) >> 16) | ((vtx_src->col & 0xFF) << 16); // RGBA --> ARGB for DirectX9
-#endif
+            vtx_dst->col = IMGUI_COL_TO_DX9_ARGB(vtx_src->col);
             vtx_dst->uv[0] = vtx_src->uv.x;
             vtx_dst->uv[1] = vtx_src->uv.y;
             vtx_dst++;
@@ -248,6 +250,13 @@ static bool ImGui_ImplDX9_CreateFontsTexture()
     int width, height, bytes_per_pixel;
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height, &bytes_per_pixel);
 
+    // Convert RGBA32 to BGRA32 as the earlier is not well supported by DX9 devices
+#ifndef IMGUI_USE_BGRA_PACKED_COLOR
+    if (io.Fonts->TexPixelsUseColors)
+        for (ImU32* p = (ImU32*)pixels, *p_end = p + width * height; p < p_end; p++)
+            *p = IMGUI_COL_TO_DX9_ARGB(*p);
+#endif
+
     // Upload texture to graphics system
     g_FontTexture = NULL;
     if (g_pd3dDevice->CreateTexture(width, height, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, &g_FontTexture, NULL) < 0)
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index bc9a75c3..75516745 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -63,6 +63,7 @@ Other Changes:
   accross all backends), facilitating compositing of the output buffer with another buffer.
   (#2693, #2764, #2766, #2873, #3447, #3813, #3816) [@ocornut, @thedmd, @ShawnM427, @Ubpa, @aiekick]
 - Backends: DX9: Fix to support IMGUI_USE_BGRA_PACKED_COLOR. (#3844) [@Xiliusha]
+- Backends: DX9: Fix to support colored glyphs, using newly introduced 'TexPixelsUseColors' info. (#3844)
 - Examples: Reworked setup of clear color to be compatible with transparent values.
 - CI: Use a dedicated "scheduled" workflow to trigger scheduled builds. Forks may disable this workflow if
   scheduled builds builds are not required. [@rokups]