Examples: DirectX9: Removed dependency on dx3x9.h so it can be used in a DirectXMath.h only environment (#611)

examples/directx9_example/imgui_impl_dx9.cpp

@@ -10,7 +10,7 @@
 #include "imgui_impl_dx9.h"
 
 // DirectX
-#include <d3dx9.h>
+#include <d3d9.h>
 #define DIRECTINPUT_VERSION 0x0800
 #include <dinput.h>
 
@@ -26,9 +26,9 @@ static int                      g_VertexBufferSize = 5000, g_IndexBufferSize = 1
 
 struct CUSTOMVERTEX
 {
-    D3DXVECTOR3 pos;
-    D3DCOLOR    col;
-    D3DXVECTOR2 uv;
+    float    pos[3];
+    D3DCOLOR col;
+    float    uv[2];
 };
 #define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE|D3DFVF_TEX1)
 
@@ -37,6 +37,11 @@ struct CUSTOMVERTEX
 // - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f)
 void ImGui_ImplDX9_RenderDrawLists(ImDrawData* draw_data)
 {
+    // Avoid rendering when minimized
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.DisplaySize.x <= 0.0f || io.DisplaySize.y <= 0.0f)
+        return;
+
     // Create and grow buffers if needed
     if (!g_pVB || g_VertexBufferSize < draw_data->TotalVtxCount)
     {
@@ -75,12 +80,12 @@ void ImGui_ImplDX9_RenderDrawLists(ImDrawData* draw_data)
         const ImDrawVert* vtx_src = &cmd_list->VtxBuffer[0];
         for (int i = 0; i < cmd_list->VtxBuffer.size(); i++)
         {
-            vtx_dst->pos.x = vtx_src->pos.x;
-            vtx_dst->pos.y = vtx_src->pos.y;
-            vtx_dst->pos.z = 0.0f;
+            vtx_dst->pos[0] = vtx_src->pos.x;
+            vtx_dst->pos[1] = vtx_src->pos.y;
+            vtx_dst->pos[2] = 0.0f;
             vtx_dst->col = (vtx_src->col & 0xFF00FF00) | ((vtx_src->col & 0xFF0000)>>16) | ((vtx_src->col & 0xFF) << 16);     // RGBA --> ARGB for DirectX9
-            vtx_dst->uv.x = vtx_src->uv.x;
-            vtx_dst->uv.y = vtx_src->uv.y;
+            vtx_dst->uv[0] = vtx_src->uv.x;
+            vtx_dst->uv[1] = vtx_src->uv.y;
             vtx_dst++;
             vtx_src++;
         }
@@ -115,12 +120,21 @@ void ImGui_ImplDX9_RenderDrawLists(ImDrawData* draw_data)
     g_pd3dDevice->SetSamplerState( 0, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR );
 
     // Setup orthographic projection matrix
-    D3DXMATRIXA16 mat;
-    D3DXMatrixIdentity(&mat);
-    g_pd3dDevice->SetTransform( D3DTS_WORLD, &mat );
-    g_pd3dDevice->SetTransform( D3DTS_VIEW, &mat );
-    D3DXMatrixOrthoOffCenterLH( &mat, 0.5f, ImGui::GetIO().DisplaySize.x+0.5f, ImGui::GetIO().DisplaySize.y+0.5f, 0.5f, -1.0f, +1.0f );
-    g_pd3dDevice->SetTransform( D3DTS_PROJECTION, &mat );
+    // Being agnostic of whether <d3dx9.h> or <DirectXMath.h> can be used, we aren't relying on D3DXMatrixIdentity()/D3DXMatrixOrthoOffCenterLH() or DirectX::XMMatrixIdentity()/DirectX::XMMatrixOrthographicOffCenterLH()
+    {
+        const float L = 0.5f, R = io.DisplaySize.x+0.5f, T = 0.5f, B = io.DisplaySize.y+0.5f;
+        D3DMATRIX mat_identity = { { 1.0f, 0.0f, 0.0f, 0.0f,  0.0f, 1.0f, 0.0f, 0.0f,  0.0f, 0.0f, 1.0f, 0.0f,  0.0f, 0.0f, 0.0f, 1.0f } };
+        D3DMATRIX mat_projection =
+        {
+            2.0f/(R-L),   0.0f,         0.0f,  0.0f,
+            0.0f,         2.0f/(T-B),   0.0f,  0.0f,
+            0.0f,         0.0f,         0.5f,  0.0f,
+            (L+R)/(L-R),  (T+B)/(B-T),  0.5f,  1.0f,
+        };
+        g_pd3dDevice->SetTransform(D3DTS_WORLD, &mat_identity);
+        g_pd3dDevice->SetTransform(D3DTS_VIEW, &mat_identity);
+        g_pd3dDevice->SetTransform(D3DTS_PROJECTION, &mat_projection);
+    }
 
     // Render command lists
     int vtx_offset = 0;
@@ -256,7 +270,7 @@ static bool ImGui_ImplDX9_CreateFontsTexture()
 
     // Upload texture to graphics system
     g_FontTexture = NULL;
-    if (D3DXCreateTexture(g_pd3dDevice, width, height, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8B8G8R8, D3DPOOL_DEFAULT, &g_FontTexture) < 0)
+    if (g_pd3dDevice->CreateTexture(width, height, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, &g_FontTexture, NULL) < 0)
         return false;
     D3DLOCKED_RECT tex_locked_rect;
     if (g_FontTexture->LockRect(0, &tex_locked_rect, NULL, 0) != D3D_OK)