save and restore sampler in GL 3 examples

examples/opengl3_example/imgui_impl_glfw_gl3.cpp

@@ -48,6 +48,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
     glActiveTexture(GL_TEXTURE0);
     GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
     GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+    GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
     GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
     GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
     GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
@@ -107,6 +108,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
             else
             {
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
+                glBindSampler(0, 0); // rely on combined texture/sampler state.
                 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);
             }
@@ -117,6 +119,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
     // Restore modified GL state
     glUseProgram(last_program);
     glBindTexture(GL_TEXTURE_2D, last_texture);
+    glBindSampler(0, last_sampler);
     glActiveTexture(last_active_texture);
     glBindVertexArray(last_vertex_array);
     glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);

examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

@@ -42,6 +42,7 @@ void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
     glActiveTexture(GL_TEXTURE0);
     GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
     GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+    GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
     GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
     GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
     GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
@@ -101,6 +102,7 @@ void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
             else
             {
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
+                glBindSampler(0, 0); // rely on combined texture/sampler state.
                 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);
             }
@@ -111,6 +113,7 @@ void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
     // Restore modified GL state
     glUseProgram(last_program);
     glBindTexture(GL_TEXTURE_2D, last_texture);
+    glBindSampler(0, last_sampler);
     glActiveTexture(last_active_texture);
     glBindVertexArray(last_vertex_array);
     glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);