Skip tonemapping for render targets with unspecified HDR headroom

src/render/direct3d11/SDL_render_d3d11.c

@@ -2230,7 +2230,7 @@ static void D3D11_SetupShaderConstants(SDL_Renderer *renderer, const SDL_RenderC
             output_headroom = renderer->HDR_headroom;
         }
 
-        if (texture->HDR_headroom > output_headroom) {
+        if (texture->HDR_headroom > output_headroom && output_headroom > 0.0f) {
             constants->tonemap_method = TONEMAP_CHROME;
             constants->tonemap_factor1 = (output_headroom / (texture->HDR_headroom * texture->HDR_headroom));
             constants->tonemap_factor2 = (1.0f / output_headroom);

src/render/direct3d12/SDL_render_d3d12.c

@@ -2667,7 +2667,7 @@ static void D3D12_SetupShaderConstants(SDL_Renderer *renderer, const SDL_RenderC
             output_headroom = renderer->HDR_headroom;
         }
 
-        if (texture->HDR_headroom > output_headroom) {
+        if (texture->HDR_headroom > output_headroom && output_headroom > 0.0f) {
             constants->tonemap_method = TONEMAP_CHROME;
             constants->tonemap_factor1 = (output_headroom / (texture->HDR_headroom * texture->HDR_headroom));
             constants->tonemap_factor2 = (1.0f / output_headroom);

src/render/gpu/SDL_render_gpu.c

@@ -917,7 +917,7 @@ static void CalculateAdvancedShaderConstants(SDL_Renderer *renderer, const SDL_R
         output_headroom = renderer->HDR_headroom;
     }
 
-    if (texture->HDR_headroom > output_headroom) {
+    if (texture->HDR_headroom > output_headroom && output_headroom > 0.0f) {
         constants->tonemap_method = TONEMAP_CHROME;
         constants->tonemap_factor1 = (output_headroom / (texture->HDR_headroom * texture->HDR_headroom));
         constants->tonemap_factor2 = (1.0f / output_headroom);

src/render/metal/SDL_render_metal.m

@@ -1459,7 +1459,7 @@ static void SetupShaderConstants(SDL_Renderer *renderer, const SDL_RenderCommand
             output_headroom = renderer->HDR_headroom;
         }
 
-        if (texture->HDR_headroom > output_headroom) {
+        if (texture->HDR_headroom > output_headroom && output_headroom > 0.0f) {
             constants->tonemap_method = TONEMAP_CHROME;
             constants->tonemap_factor1 = (output_headroom / (texture->HDR_headroom * texture->HDR_headroom));
             constants->tonemap_factor2 = (1.0f / output_headroom);

src/render/vulkan/SDL_render_vulkan.c

@@ -3472,7 +3472,7 @@ static void VULKAN_SetupShaderConstants(SDL_Renderer *renderer, const SDL_Render
             output_headroom = renderer->HDR_headroom;
         }
 
-        if (texture->HDR_headroom > output_headroom) {
+        if (texture->HDR_headroom > output_headroom && output_headroom > 0.0f) {
             constants->tonemap_method = TONEMAP_CHROME;
             constants->tonemap_factor1 = (output_headroom / (texture->HDR_headroom * texture->HDR_headroom));
             constants->tonemap_factor2 = (1.0f / output_headroom);