Examples: Most examples apps detect if ImDrawIdx was changed to 32-bits instead of 16

examples/allegro5_example/imgui_impl_a5.cpp

@@ -56,7 +56,8 @@ void ImGui_ImplA5_RenderDrawLists(ImDrawData* draw_data)
             vertices[i] = v;
         }
 
-        // FIXME-OPT: Unfortunately Allegro doesn't support 16-bit vertices
+        // FIXME-OPT: Unfortunately Allegro doesn't support 16-bit indices
+        // You can also use '#define ImDrawIdx unsigned int' in imconfig.h and request ImGui to output 32-bit indices
         static ImVector<int> indices;
         indices.resize(cmd_list->IdxBuffer.size());
         for (int i = 0; i < cmd_list->IdxBuffer.size(); ++i) 

examples/directx11_example/imgui_impl_dx11.cpp

@@ -132,7 +132,7 @@ void ImGui_ImplDX11_RenderDrawLists(ImDrawData* draw_data)
     unsigned int offset = 0;
     g_pd3dDeviceContext->IASetInputLayout(g_pInputLayout);
     g_pd3dDeviceContext->IASetVertexBuffers(0, 1, &g_pVB, &stride, &offset);
-    g_pd3dDeviceContext->IASetIndexBuffer(g_pIB, DXGI_FORMAT_R16_UINT, 0);
+    g_pd3dDeviceContext->IASetIndexBuffer(g_pIB, sizeof(ImDrawIdx) == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT, 0);
     g_pd3dDeviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
     g_pd3dDeviceContext->VSSetShader(g_pVertexShader, NULL, 0);
     g_pd3dDeviceContext->VSSetConstantBuffers(0, 1, &g_pVertexConstantBuffer);

examples/directx9_example/imgui_impl_dx9.cpp

@@ -47,7 +47,7 @@ void ImGui_ImplDX9_RenderDrawLists(ImDrawData* draw_data)
     {
         if (g_pIB) { g_pIB->Release(); g_pIB = NULL; }
         g_IndexBufferSize = draw_data->TotalIdxCount + 10000;
-        if (g_pd3dDevice->CreateIndexBuffer(g_IndexBufferSize * sizeof(ImDrawIdx), D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY, D3DFMT_INDEX16, D3DPOOL_DEFAULT, &g_pIB, NULL) < 0)
+        if (g_pd3dDevice->CreateIndexBuffer(g_IndexBufferSize * sizeof(ImDrawIdx), D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY, sizeof(ImDrawIdx) == 2 ? D3DFMT_INDEX16 : D3DFMT_INDEX32, D3DPOOL_DEFAULT, &g_pIB, NULL) < 0)
             return;
     }
 

examples/opengl3_example/imgui_impl_glfw_gl3.cpp

@@ -98,7 +98,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
             {
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
                 glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
-                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer_offset);
+                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset);
             }
             idx_buffer_offset += pcmd->ElemCount;
         }

examples/opengl_example/imgui_impl_glfw.cpp

@@ -81,7 +81,7 @@ void ImGui_ImplGlfw_RenderDrawLists(ImDrawData* draw_data)
             {
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
                 glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
-                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer);
+                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer);
             }
             idx_buffer += pcmd->ElemCount;
         }

examples/sdl_opengl_example/imgui_impl_sdl.cpp

@@ -74,7 +74,7 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
             {
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
                 glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
-                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer);
+                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer);
             }
             idx_buffer += pcmd->ElemCount;
         }