Using TextureRef for submitting the scene render to ImGui::Image()

3rdparty/imgui/examples/opengl3_example/imgui_impl_glfw_gl3.cpp

@@ -114,7 +114,18 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
             }
             else
             {
-                glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
+                intptr_t ptr = (intptr_t)pcmd->TextureId;
+
+                // MOD START (martin), 2018-03-09: support texture references that point to an address of a texture id
+                if (ptr > 1024 * 1024)
+                {
+                    GLTextureRef* texture_ref = (GLTextureRef*)pcmd->TextureId;
+                    GLuint* texture_ptr = (GLuint*) texture_ref->mTextureIdPtr;
+                    glBindTexture(GL_TEXTURE_2D, *texture_ptr);
+                } else {
+                    glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
+                }
+                // MOD END (martin), 2018-03-09: support texture references that point to an address of a texture id
                 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, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset);
             }

3rdparty/imgui/examples/opengl3_example/imgui_impl_glfw_gl3.h

@@ -13,6 +13,16 @@
 
 struct GLFWwindow;
 
+// MOD START (martin), 2018-03-09: support texture references that point to an address of a texture id
+union GLTextureRef {
+		int mTextureId;
+		struct {
+			int magic;
+			unsigned int* mTextureIdPtr;
+		};
+};
+// MOD END (martin), 2018-03-09: support texture references that point to an address of a texture id
+
 IMGUI_API bool        ImGui_ImplGlfwGL3_Init(GLFWwindow* window, bool install_callbacks);
 IMGUI_API void        ImGui_ImplGlfwGL3_Shutdown();
 IMGUI_API void        ImGui_ImplGlfwGL3_NewFrame();

src/modules/RenderModule.cc

@@ -517,19 +517,19 @@ void Renderer::RenderGui() {
 	if (ImGui::BeginDock("Scene")) {
 		ImGui::Checkbox("Draw Depth", &mSettings->DrawDepth);
 
-		GLuint texture;
 		if (mSettings->DrawDepth) {
-			texture = mRenderTarget.mLinearizedDepthTexture;
+			mRenderTextureRef.mTextureIdPtr = &mRenderTarget.mLinearizedDepthTexture;
 		} else {
-			texture = mRenderTarget.mColorTexture;
+			mRenderTextureRef.mTextureIdPtr = &mRenderTarget.mColorTexture;
 		}
 
 		ImGui::Text("Scene");
 		const ImVec2 content_avail = ImGui::GetContentRegionAvail();
 		mSceneAreaWidth = content_avail.x;
 		mSceneAreaHeight = content_avail.y;
-	
+
-		ImGui::Image((void*) texture,
+		mRenderTextureRef.magic = (GLuint)0xbadface;
+		ImGui::Image((void*) &mRenderTextureRef,
 				content_avail,
 				ImVec2(0.0f, 1.0f), 
 				ImVec2(1.0f, 0.0f)

src/modules/RenderModule.h

@@ -8,6 +8,8 @@
 #include "math_types.h"
 
 #include <GL/gl3w.h>    // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you.
+#include "imgui.h"
+#include "imgui_impl_glfw_gl3.h"
 
 #include "Globals.h"
 #include "RenderUtils.h"
@@ -125,6 +127,7 @@ struct Renderer {
 	GLuint muDefaultColor;
 
 	RenderTarget mRenderTarget;
+	GLTextureRef mRenderTextureRef = { (int)0xbadface };
 
 	GLuint mRenderQuadVertexArrayId;
 	GLuint mRenderQuadVertexBufferId;