Added support for 1+ textures to ImGui renderer

This was not possible to use textures other than the font texture with the
ImGui renderer. To address that limitation, this commit adds support for
one or more textures by updating the SRB's variable when needed.

1 files changed, 15 insertions, 10 deletions

diff --git a/Imgui/src/ImGuiDiligentRenderer.cpp b/Imgui/src/ImGuiDiligentRenderer.cpp
index a446f5c..0ef4028 100644
--- a/Imgui/src/ImGuiDiligentRenderer.cpp
+++ b/Imgui/src/ImGuiDiligentRenderer.cpp
@@ -336,7 +336,7 @@ void ImGuiDiligentRenderer::CreateDeviceObjects()
 
     ShaderResourceVariableDesc Variables[] =
         {
-            {SHADER_TYPE_PIXEL, "Texture", SHADER_RESOURCE_VARIABLE_TYPE_MUTABLE} //
+            {SHADER_TYPE_PIXEL, "Texture", SHADER_RESOURCE_VARIABLE_TYPE_DYNAMIC} //
         };
     PSODesc.ResourceLayout.Variables    = Variables;
     PSODesc.ResourceLayout.NumVariables = _countof(Variables);
@@ -393,7 +393,6 @@ void ImGuiDiligentRenderer::CreateFontsTexture()
 
     m_pSRB.Release();
     m_pPSO->CreateShaderResourceBinding(&m_pSRB, true);
-    m_pSRB->GetVariableByName(SHADER_TYPE_PIXEL, "Texture")->Set(m_pFontSRV);
 
     // Store our identifier
     io.Fonts->TexID = (ImTextureID)m_pFontSRV;
@@ -635,7 +634,6 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
         pCtx->SetVertexBuffers(0, 1, pVBs, Offsets, RESOURCE_STATE_TRANSITION_MODE_TRANSITION, SET_VERTEX_BUFFERS_FLAG_RESET);
         pCtx->SetIndexBuffer(m_pIB, 0, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
         pCtx->SetPipelineState(m_pPSO);
-        pCtx->CommitShaderResources(m_pSRB, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
 
         const float blend_factor[4] = {0.f, 0.f, 0.f, 0.f};
         pCtx->SetBlendFactors(blend_factor);
@@ -656,8 +654,9 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
 
     // Render command lists
     // (Because we merged all buffers into a single one, we maintain our own offset into them)
-    int global_idx_offset = 0;
-    int global_vtx_offset = 0;
+    int           global_idx_offset = 0;
+    int           global_vtx_offset = 0;
+    ITextureView* pLastTextureView  = nullptr;
 
     for (int n = 0; n < pDrawData->CmdListsCount; n++)
     {
@@ -699,11 +698,17 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
                                       static_cast<Uint32>(m_RenderSurfaceWidth * pDrawData->FramebufferScale.x),
                                       static_cast<Uint32>(m_RenderSurfaceHeight * pDrawData->FramebufferScale.y));
 
-                // Bind texture, Draw
-                auto* texture_srv = reinterpret_cast<ITextureView*>(pcmd->TextureId);
-                VERIFY_EXPR(texture_srv == m_pFontSRV);
-                (void)texture_srv;
-                //ctx->PSSetShaderResources(0, 1, &texture_srv);
+                // Bind texture
+                auto pTextureView = reinterpret_cast<ITextureView*>(pcmd->TextureId);
+                VERIFY_EXPR(pTextureView);
+                if (pTextureView != pLastTextureView)
+                {
+                    pLastTextureView = pTextureView;
+                    m_pSRB->GetVariableByName(SHADER_TYPE_PIXEL, "Texture")->Set(pTextureView);
+                    pCtx->CommitShaderResources(m_pSRB, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
+                }
+
+                // Draw
                 DrawIndexedAttribs DrawAttrs(pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? VT_UINT16 : VT_UINT32, DRAW_FLAG_VERIFY_STATES);
                 DrawAttrs.FirstIndexLocation = pcmd->IdxOffset + global_idx_offset;
                 DrawAttrs.BaseVertex         = pcmd->VtxOffset + global_vtx_offset;