From 9fe200c215b334dbc115a4033d751bc0049b42e1 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Fri, 22 May 2026 10:35:41 -0400
Subject: [PATCH] examples/renderer/20-blending: Note when a blend mode is
unsupported.
---
examples/renderer/20-blending/blending.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/examples/renderer/20-blending/blending.c b/examples/renderer/20-blending/blending.c
index 9cea912779530..9c681892821ed 100644
--- a/examples/renderer/20-blending/blending.c
+++ b/examples/renderer/20-blending/blending.c
@@ -211,14 +211,25 @@ SDL_AppResult SDL_AppIterate(void *appstate)
SDL_FRect blue_dst = { panels[i].x + BLUE_OFFSET, panels[i].y + BLUE_OFFSET, RECT_SIZE, RECT_SIZE };
/* Apply the current blend mode */
- SDL_SetTextureBlendMode(red_rect_texture, blend_modes[i]);
+ const bool supported = SDL_SetTextureBlendMode(red_rect_texture, blend_modes[i]); /* just make sure the renderer supports this blend mode */
SDL_SetTextureBlendMode(green_rect_texture, blend_modes[i]);
- SDL_SetTextureBlendMode(blue_rect_texture, blend_modes[i]);
+ SDL_SetTextureBlendMode(blue_rect_texture, blend_modes[i]);
/* Render textures */
SDL_RenderTexture(renderer, red_rect_texture, NULL, &red_dst);
SDL_RenderTexture(renderer, green_rect_texture, NULL, &green_dst);
SDL_RenderTexture(renderer, blue_rect_texture, NULL, &blue_dst);
+
+ /* Not all renderers support all blend modes. The renderer will try to pick something close in this case,
+ but it should be noted that the results might be unexpected, so we add "[UNSUPPORTED]" to this panel. */
+ if (!supported) {
+ const float textwidth = 104.0f;
+ const SDL_FRect dst = { panels[i].x + ((panels[i].w - textwidth) / 2.0f), panels[i].y + (panels[i].h - 8), textwidth, 8 };
+ SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
+ SDL_RenderFillRect(renderer, &dst);
+ SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE);
+ SDL_RenderDebugText(renderer, dst.x, dst.y, "[UNSUPPORTED]");
+ }
}
SDL_RenderPresent(renderer);