Added comments about requirement for bilinear filtering. (#5156, #3245) + Backends: SDL_Renderer: Explicitely call SDL_SetTextureScaleMode(). (#4927)

backends/imgui_impl_allegro5.cpp

@@ -207,6 +207,7 @@ bool ImGui_ImplAllegro5_CreateDeviceObjects()
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
 
     // Create texture
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     int flags = al_get_new_bitmap_flags();
     int fmt = al_get_new_bitmap_format();
     al_set_new_bitmap_flags(ALLEGRO_MEMORY_BITMAP | ALLEGRO_MIN_LINEAR | ALLEGRO_MAG_LINEAR);

backends/imgui_impl_dx10.cpp

@@ -337,6 +337,7 @@ static void ImGui_ImplDX10_CreateFontsTexture()
     io.Fonts->SetTexID((ImTextureID)bd->pFontTextureView);
 
     // Create texture sampler
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     {
         D3D10_SAMPLER_DESC desc;
         ZeroMemory(&desc, sizeof(desc));

backends/imgui_impl_dx11.cpp

@@ -349,6 +349,7 @@ static void ImGui_ImplDX11_CreateFontsTexture()
     io.Fonts->SetTexID((ImTextureID)bd->pFontTextureView);
 
     // Create texture sampler
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     {
         D3D11_SAMPLER_DESC desc;
         ZeroMemory(&desc, sizeof(desc));

backends/imgui_impl_dx12.cpp

@@ -466,6 +466,7 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
         param[1].DescriptorTable.pDescriptorRanges = &descRange;
         param[1].ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
 
+        // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
         D3D12_STATIC_SAMPLER_DESC staticSampler = {};
         staticSampler.Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;
         staticSampler.AddressU = D3D12_TEXTURE_ADDRESS_MODE_WRAP;

backends/imgui_impl_dx9.cpp

@@ -84,7 +84,7 @@ static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
     vp.MaxZ = 1.0f;
     bd->pd3dDevice->SetViewport(&vp);
 
-    // Setup render state: fixed-pipeline, alpha-blending, no face culling, no depth testing, shade mode (for gradient)
+    // Setup render state: fixed-pipeline, alpha-blending, no face culling, no depth testing, shade mode (for gradient), bilinear sampling.
     bd->pd3dDevice->SetPixelShader(NULL);
     bd->pd3dDevice->SetVertexShader(NULL);
     bd->pd3dDevice->SetRenderState(D3DRS_FILLMODE, D3DFILL_SOLID);

backends/imgui_impl_metal.mm

@@ -350,6 +350,7 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
     return renderPipelineState;
 }
 
+// Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
 - (id<MTLRenderPipelineState>)_renderPipelineStateForFramebufferDescriptor:(FramebufferDescriptor *)descriptor device:(id<MTLDevice>)device
 {
     NSError *error = nil;

backends/imgui_impl_opengl2.cpp

@@ -244,6 +244,7 @@ bool ImGui_ImplOpenGL2_CreateFontsTexture()
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
 
     // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     GLint last_texture;
     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     glGenTextures(1, &bd->FontTexture);

backends/imgui_impl_opengl3.cpp

@@ -539,6 +539,7 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
 
     // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     GLint last_texture;
     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     glGenTextures(1, &bd->FontTexture);

backends/imgui_impl_sdlrenderer.cpp

@@ -210,6 +210,7 @@ bool ImGui_ImplSDLRenderer_CreateFontsTexture()
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
 
     // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     bd->FontTexture = SDL_CreateTexture(bd->SDLRenderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
     if (bd->FontTexture == NULL)
     {
@@ -218,6 +219,7 @@ bool ImGui_ImplSDLRenderer_CreateFontsTexture()
     }
     SDL_UpdateTexture(bd->FontTexture, NULL, pixels, 4 * width);
     SDL_SetTextureBlendMode(bd->FontTexture, SDL_BLENDMODE_BLEND);
+    SDL_SetTextureScaleMode(bd->FontTexture, SDL_ScaleModeLinear);
 
     // Store our identifier
     io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);

backends/imgui_impl_vulkan.cpp

@@ -741,6 +741,7 @@ static void ImGui_ImplVulkan_CreateFontSampler(VkDevice device, const VkAllocati
     if (bd->FontSampler)
         return;
 
+    // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
     VkSamplerCreateInfo info = {};
     info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
     info.magFilter = VK_FILTER_LINEAR;

backends/imgui_impl_wgpu.cpp

@@ -509,6 +509,7 @@ static void ImGui_ImplWGPU_CreateFontsTexture()
     }
 
     // Create the associated sampler
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     {
         WGPUSamplerDescriptor sampler_desc = {};
         sampler_desc.minFilter = WGPUFilterMode_Linear;