ImDrawCallback_ResetRenderState, Examples: Added support for reset render state callback. (#2037, #1639, #2452)

This commit is contained in:
omar
2019-04-30 22:15:59 +02:00
parent 3fbc0b7a9e
commit 5c1cd5c8c7
10 changed files with 394 additions and 294 deletions

View File

@ -72,24 +72,9 @@ void ImGui_ImplOpenGL2_NewFrame()
ImGui_ImplOpenGL2_CreateDeviceObjects();
}
// OpenGL2 Render function.
// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
if (fb_width == 0 || fb_height == 0)
return;
// We are using the OpenGL fixed pipeline to make the example code simpler to read!
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill.
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
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);
glDisable(GL_CULL_FACE);
@ -121,6 +106,28 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
}
// OpenGL2 Render function.
// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
if (fb_width == 0 || fb_height == 0)
return;
// Backup GL state
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
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);
// Setup desired GL state
ImGui_ImplOpenGL2_SetupRenderState(draw_data, fb_width, fb_height);
// Will project scissor/clipping rectangles into framebuffer space
ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
@ -141,8 +148,12 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback)
{
// User callback (registered via ImDrawList::AddCallback)
pcmd->UserCallback(cmd_list, pcmd);
// User callback, registered via ImDrawList::AddCallback()
// (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
ImGui_ImplOpenGL2_SetupRenderState(draw_data, fb_width, fb_height);
else
pcmd->UserCallback(cmd_list, pcmd);
}
else
{
@ -167,7 +178,7 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
}
}
// Restore modified state
// Restore modified GL state
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);