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Examples: added simple drawing app example for using ImDrawList and custom drawing

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ocornut
2015-01-23 01:38:04 +01:00
parent 32b8ad7381
commit 638babb0dd
1 changed files with 66 additions and 0 deletions
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66
imgui.cpp
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@@ -7525,6 +7525,7 @@ static void ShowExampleAppConsole(bool* opened);
static void ShowExampleAppLongText(bool* opened);
static void ShowExampleAppAutoResize(bool* opened);
static void ShowExampleAppFixedOverlay(bool* opened);
static void ShowExampleAppCustomRendering(bool* opened);
// Demonstrate ImGui features (unfortunately this makes this function a little bloated!)
void ImGui::ShowTestWindow(bool* opened)
@@ -8067,12 +8068,14 @@ void ImGui::ShowTestWindow(bool* opened)
static bool show_app_long_text = false;
static bool show_app_auto_resize = false;
static bool show_app_fixed_overlay = false;
static bool show_app_custom_rendering = false;
if (ImGui::CollapsingHeader("App Examples"))
{
ImGui::Checkbox("Console", &show_app_console);
ImGui::Checkbox("Long text display", &show_app_long_text);
ImGui::Checkbox("Auto-resizing window", &show_app_auto_resize);
ImGui::Checkbox("Simple overlay", &show_app_fixed_overlay);
ImGui::Checkbox("Custom rendering", &show_app_custom_rendering);
}
if (show_app_console)
ShowExampleAppConsole(&show_app_console);
@@ -8082,6 +8085,8 @@ void ImGui::ShowTestWindow(bool* opened)
ShowExampleAppAutoResize(&show_app_auto_resize);
if (show_app_fixed_overlay)
ShowExampleAppFixedOverlay(&show_app_fixed_overlay);
if (show_app_custom_rendering)
ShowExampleAppCustomRendering(&show_app_custom_rendering);
ImGui::End();
}
@@ -8119,6 +8124,67 @@ static void ShowExampleAppFixedOverlay(bool* opened)
ImGui::End();
}
static void ShowExampleAppCustomRendering(bool* opened)
{
if (!ImGui::Begin("Example: Custom Rendering", opened))
{
ImGui::End();
return;
}
// Tip: If you do a lot of custom rendering, you probably want to use your own geometrical types and benefit of overloaded operators, etc.
// Define IM_VEC2_CLASS_EXTRA in imconfig.h to create implicit conversions between your types and ImVec2/ImVec4.
// ImGui defines overloaded operators but they are internal to imgui.cpp and not exposed outside (to avoid messing with your types)
// In this example we aren't using the operators.
static ImVector<ImVec2> points;
static bool adding_line = false;
if (ImGui::Button("Clear")) points.clear();
if (points.size() > 2) { ImGui::SameLine(); if (ImGui::Button("Undo")) points.pop_back(); }
ImGui::Text("Left-click and drag to add lines");
ImGui::Text("Right-click to undo");
ImDrawList* draw_list = ImGui::GetWindowDrawList();
// Here we are using InvisibleButton() as a convenience to 1) advance the cursor and 2) allows us to use IsItemHovered()
// However you can draw directly and poll mouse/keyboard by yourself. You can manipulate the cursor using GetCursorPos() and SetCursorPos().
// If you only use the ImDrawList API, you can notify the owner window of its extends by using SetCursorPos(max) followed by an empty Text("") statement.
ImVec2 canvas_pos = ImGui::GetCursorScreenPos(); // ImDrawList API uses screen coordinates!
ImVec2 canvas_size = ImVec2(ImMin(50.0f,ImGui::GetWindowContentRegionMax().x-ImGui::GetCursorPos().x), ImMin(50.0f,ImGui::GetWindowContentRegionMax().y-ImGui::GetCursorPos().y)); // Resize canvas what's available
draw_list->AddRect(canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), 0xFFFFFFFF);
bool adding_preview = false;
ImGui::InvisibleButton("canvas", canvas_size);
if (ImGui::IsItemHovered())
{
ImVec2 mouse_pos_in_canvas = ImVec2(ImGui::GetIO().MousePos.x - canvas_pos.x, ImGui::GetIO().MousePos.y - canvas_pos.y);
if (!adding_line && ImGui::GetIO().MouseClicked[0])
{
points.push_back(mouse_pos_in_canvas);
adding_line = true;
}
if (adding_line)
{
adding_preview = true;
points.push_back(mouse_pos_in_canvas);
if (!ImGui::GetIO().MouseDown[0])
adding_line = adding_preview = false;
}
if (ImGui::GetIO().MouseClicked[1] && !points.empty())
{
adding_line = false;
points.pop_back();
points.pop_back();
}
}
draw_list->PushClipRect(ImVec4(canvas_pos.x, canvas_pos.y, canvas_pos.x+canvas_size.x, canvas_pos.y+canvas_size.y)); // clip lines within the canvas (if we resize it, etc.)
for (int i = 0; i < (int)points.size() - 1; i += 2)
draw_list->AddLine(ImVec2(canvas_pos.x + points[i].x, canvas_pos.y + points[i].y), ImVec2(canvas_pos.x + points[i+1].x, canvas_pos.y + points[i+1].y), 0xFF00FFFF);
draw_list->PopClipRect();
if (adding_preview)
points.pop_back();
ImGui::End();
}
struct ExampleAppConsole
{
char InputBuf[256];