Examples: OpenGL*: Savnig/restoring existing scissor rectangle for completeness (#807)

examples/opengl2_example/imgui_impl_glfw.cpp

@@ -46,6 +46,7 @@ void ImGui_ImplGlfw_RenderDrawLists(ImDrawData* draw_data)
     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers.
     GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); 
     glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT);
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@@ -108,6 +109,7 @@ void ImGui_ImplGlfw_RenderDrawLists(ImDrawData* draw_data)
     glPopMatrix();
     glPopAttrib();
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
 }
 
 static const char* ImGui_ImplGlfw_GetClipboardText()

examples/opengl3_example/imgui_impl_glfw_gl3.cpp

@@ -55,6 +55,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
     GLint last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, &last_blend_equation_rgb);
     GLint last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, &last_blend_equation_alpha);
     GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); 
     GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
     GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
     GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
@@ -125,6 +126,7 @@ void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
     if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
     if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
 }
 
 static const char* ImGui_ImplGlfwGL3_GetClipboardText()

examples/sdl_opengl2_example/imgui_impl_sdl.cpp

@@ -35,6 +35,7 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers.
     GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); 
     glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT);
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@@ -97,6 +98,7 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
     glPopMatrix();
     glPopAttrib();
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
 }
 
 static const char* ImGui_ImplSdl_GetClipboardText()

examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

@@ -49,6 +49,7 @@ void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
     GLint last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, &last_blend_equation_rgb);
     GLint last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, &last_blend_equation_alpha);
     GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); 
     GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
     GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
     GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
@@ -119,6 +120,7 @@ void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
     if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
     if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
 }
 
 static const char* ImGui_ImplSdlGL3_GetClipboardText()