From 37550b59d4c12cd9e1573692a67a92df515ec563 Mon Sep 17 00:00:00 2001
From: Thomas Rohloff <v10lator@myway.de>
Date: Sun, 18 Jul 2021 08:10:57 +0200
Subject: [PATCH] Add GuiImage:setBlendMode

Signed-off-by: Thomas Rohloff <v10lator@myway.de>
---
 include/gui-sdl/gui/GuiImage.h |  5 +++++
 source/gui/GuiImage.cpp        | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/gui-sdl/gui/GuiImage.h b/include/gui-sdl/gui/GuiImage.h
index 8a4e54d..923e8fd 100644
--- a/include/gui-sdl/gui/GuiImage.h
+++ b/include/gui-sdl/gui/GuiImage.h
@@ -41,10 +41,15 @@ public:
 
     void setTexture(GuiTextureData *tex);
 
+    int setBlendMode(SDL_BlendMode blendMode);
+
 private:
     GuiTextureData *texture = nullptr;
     bool freeTextureData = false;
 
     // Color of the rect that's drawn if the picture has no texture.
     SDL_Color color = {0, 0, 0, 0};
+
+protected:
+    SDL_BlendMode blendMode;
 };
diff --git a/source/gui/GuiImage.cpp b/source/gui/GuiImage.cpp
index fad3231..8682c06 100644
--- a/source/gui/GuiImage.cpp
+++ b/source/gui/GuiImage.cpp
@@ -47,11 +47,24 @@ void GuiImage::draw(Renderer *renderer) {
     if (texture) {
         texture->draw(renderer, rect, getAngle());
     } else {
+        // copy the texture to the rendering context
+        SDL_BlendMode mode;
+        SDL_GetRenderDrawBlendMode(renderer->getRenderer(), &mode);
+
+        // adjust blend mode
+        if(blendMode != mode){
+            SDL_SetRenderDrawBlendMode(renderer->getRenderer(), blendMode);
+        }
+
         SDL_SetRenderDrawColor(renderer->getRenderer(), color.r, color.g, color.b, color.a);
         SDL_RenderFillRect(renderer->getRenderer(), &rect);
         if(getAngle() != 0.0f){
             LG_Log("Drawing a rotated rect is not supported yet");
         }
+        
+        if(blendMode != mode){
+            SDL_SetRenderDrawBlendMode(renderer->getRenderer(), mode);
+        }
     }
 }
 
@@ -64,3 +77,8 @@ void GuiImage::setTexture(GuiTextureData *tex) {
         this->setSize(tex->getWidth(), tex->getHeight());
     }
 }
+
+int GuiImage::setBlendMode(SDL_BlendMode blendMode) {
+    this->blendMode = blendMode;
+    return this->texture ? this->texture->setBlendMode(blendMode) : 0;
+}