> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/ocornut/imgui/llms.txt
> Use this file to discover all available pages before exploring further.
# Vectors & Data Types
> Core data types including ImVec2, ImVec4, ImColor, and scalar types
## Vector Types
### ImVec2
2D vector used to store positions, sizes, etc.
```cpp theme={null}
struct ImVec2
{
float x, y;
constexpr ImVec2() : x(0.0f), y(0.0f) { }
constexpr ImVec2(float _x, float _y) : x(_x), y(_y) { }
float& operator[] (size_t idx);
float operator[] (size_t idx) const;
};
```
**Example:**
```cpp theme={null}
ImVec2 pos(100.0f, 200.0f);
ImVec2 size(300.0f, 400.0f);
// Access components
float x = pos.x;
float y = pos.y;
// Or by index
float x = pos[0];
float y = pos[1];
```
Add `#define IMGUI_DEFINE_MATH_OPERATORS` before including imgui.h to access math operators for ImVec2 and ImVec4.
**With Math Operators:**
```cpp theme={null}
#define IMGUI_DEFINE_MATH_OPERATORS
#include "imgui.h"
ImVec2 a(10, 20);
ImVec2 b(5, 15);
ImVec2 c = a + b; // (15, 35)
ImVec2 d = a - b; // (5, 5)
ImVec2 e = a * 2.0f; // (20, 40)
ImVec2 f = a / 2.0f; // (5, 10)
```
### ImVec4
4D vector used to store clipping rectangles, colors, etc.
```cpp theme={null}
struct ImVec4
{
float x, y, z, w;
constexpr ImVec4() : x(0.0f), y(0.0f), z(0.0f), w(0.0f) { }
constexpr ImVec4(float _x, float _y, float _z, float _w) : x(_x), y(_y), z(_z), w(_w) { }
};
```
**Example:**
```cpp theme={null}
// As a color (RGBA)
ImVec4 red(1.0f, 0.0f, 0.0f, 1.0f);
ImVec4 semi_transparent_blue(0.0f, 0.0f, 1.0f, 0.5f);
// As a clipping rectangle
ImVec4 clip_rect(10.0f, 20.0f, 200.0f, 300.0f);
```
## Scalar Types
### Integer Types
```cpp theme={null}
typedef signed char ImS8; // 8-bit signed integer
typedef unsigned char ImU8; // 8-bit unsigned integer
typedef signed short ImS16; // 16-bit signed integer
typedef unsigned short ImU16; // 16-bit unsigned integer
typedef signed int ImS32; // 32-bit signed integer == int
typedef unsigned int ImU32; // 32-bit unsigned integer
typedef signed long long ImS64; // 64-bit signed integer
typedef unsigned long long ImU64; // 64-bit unsigned integer
```
**Example:**
```cpp theme={null}
ImU32 color = IM_COL32(255, 128, 64, 255);
ImS32 index = 42;
ImU64 large_value = 0xFFFFFFFFFFFFFFFF;
```
### ImGuiID
```cpp theme={null}
typedef unsigned int ImGuiID; // Unique ID used by widgets
```
A unique ID used by widgets, typically the result of hashing a stack of strings.
**Example:**
```cpp theme={null}
ImGuiID id = ImGui::GetID("MyWidget");
ImGuiID id2 = ImGui::GetID((void*)&my_object);
```
### Character Types
```cpp theme={null}
typedef unsigned int ImWchar32; // Decoded U32 character/code point
typedef unsigned short ImWchar16; // Decoded U16 character/code point
#ifdef IMGUI_USE_WCHAR32
typedef ImWchar32 ImWchar;
#else
typedef ImWchar16 ImWchar; // Default
#endif
```
## Drawing Types
### ImDrawIdx
```cpp theme={null}
#ifndef ImDrawIdx
typedef unsigned short ImDrawIdx; // Default: 16-bit (for maximum compatibility)
#endif
```
Vertex index. Can be overridden in imconfig.h to use 32-bit indices:
```cpp theme={null}
#define ImDrawIdx unsigned int
```
To use 16-bit indices with large meshes (64K+ vertices), backend needs to set `io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset`.
### ImDrawVert
```cpp theme={null}
struct ImDrawVert
{
ImVec2 pos; // Position
ImVec2 uv; // Texture coordinates
ImU32 col; // Color (32-bit packed RGBA)
};
```
Vertex structure used for rendering. Total size: 20 bytes by default.
**Example:**
```cpp theme={null}
ImDrawVert vert;
vert.pos = ImVec2(100.0f, 200.0f);
vert.uv = ImVec2(0.0f, 0.0f);
vert.col = IM_COL32(255, 255, 255, 255);
```
You can override the vertex format by defining `IMGUI_OVERRIDE_DRAWVERT_STRUCT_LAYOUT` in imconfig.h.
## Texture Types
### ImTextureID
```cpp theme={null}
#ifndef ImTextureID
typedef ImU64 ImTextureID; // Default: 64-bit
#endif
#define ImTextureID_Invalid ((ImTextureID)0)
```
Backend-specific, low-level identifier for a texture. Can be overridden in imconfig.h:
```cpp theme={null}
#define ImTextureID MyTextureType*
```
**Example:**
```cpp theme={null}
// OpenGL
ImTextureID my_tex_id = (ImTextureID)(intptr_t)opengl_texture_id;
// DirectX 11
ImTextureID my_tex_id = (ImTextureID)(intptr_t)srv;
// Vulkan
ImTextureID my_tex_id = (ImTextureID)(VkDescriptorSet)descriptor_set;
```
### ImTextureRef
```cpp theme={null}
struct ImTextureRef
{
ImTextureRef();
ImTextureRef(ImTextureID tex_id);
inline ImTextureID GetTexID() const;
ImTextureData* _TexData; // Texture owned by font atlas
ImTextureID _TexID; // Low-level backend texture ID
};
```
Higher-level texture identifier that can reference either:
* A texture owned by the font atlas (`_TexData`)
* A user-provided texture (`_TexID`)
**Example:**
```cpp theme={null}
// From custom texture
ImTextureRef tex_ref((ImTextureID)(intptr_t)my_texture);
ImGui::Image(tex_ref, ImVec2(100, 100));
// From font atlas
ImTextureRef atlas_tex = io.Fonts->TexRef;
```
## Color Types
### ImColor (Obsolete)
```cpp theme={null}
struct ImColor
{
ImVec4 Value;
ImColor();
ImColor(float r, float g, float b, float a = 1.0f);
ImColor(const ImVec4& col);
ImColor(ImU32 rgba);
operator ImU32() const;
operator ImVec4() const;
};
```
ImColor is obsolete. Please avoid using it. Use `ImU32` or `ImVec4` directly instead.
**Modern alternative:**
```cpp theme={null}
// Instead of ImColor
ImColor old_way(1.0f, 0.0f, 0.0f, 1.0f);
// Use ImVec4 or ImU32
ImVec4 new_way(1.0f, 0.0f, 0.0f, 1.0f);
ImU32 packed = IM_COL32(255, 0, 0, 255);
```
## Direction Enum
```cpp theme={null}
enum ImGuiDir : int
{
ImGuiDir_None = -1,
ImGuiDir_Left = 0,
ImGuiDir_Right = 1,
ImGuiDir_Up = 2,
ImGuiDir_Down = 3,
ImGuiDir_COUNT
};
```
Cardinal direction.
**Example:**
```cpp theme={null}
ImGuiStyle& style = ImGui::GetStyle();
style.WindowMenuButtonPosition = ImGuiDir_Right;
style.ColorButtonPosition = ImGuiDir_Left;
```
## Sort Direction
```cpp theme={null}
enum ImGuiSortDirection : ImU8
{
ImGuiSortDirection_None = 0,
ImGuiSortDirection_Ascending = 1,
ImGuiSortDirection_Descending = 2
};
```
Sorting direction for tables.
## Common Patterns
### Vector Arithmetic (with IMGUI\_DEFINE\_MATH\_OPERATORS)
```cpp theme={null}
#define IMGUI_DEFINE_MATH_OPERATORS
#include "imgui.h"
// Calculate center point
ImVec2 min(10, 20);
ImVec2 max(100, 80);
ImVec2 center = (min + max) * 0.5f;
// Calculate size
ImVec2 size = max - min;
// Offset position
ImVec2 pos(50, 50);
ImVec2 offset(10, 20);
ImVec2 new_pos = pos + offset;
```
### Color Conversions
```cpp theme={null}
// ImVec4 to ImU32
ImVec4 color_vec(1.0f, 0.5f, 0.25f, 1.0f);
ImU32 color_u32 = ImGui::ColorConvertFloat4ToU32(color_vec);
// ImU32 to ImVec4
ImU32 packed = IM_COL32(255, 128, 64, 255);
ImVec4 unpacked = ImGui::ColorConvertU32ToFloat4(packed);
// Direct construction
ImU32 red = IM_COL32(255, 0, 0, 255);
ImVec4 red_f(1.0f, 0.0f, 0.0f, 1.0f);
```
### Rectangle Math
```cpp theme={null}
ImVec2 rect_min(10, 20);
ImVec2 rect_max(100, 80);
// Size
ImVec2 size = ImVec2(rect_max.x - rect_min.x, rect_max.y - rect_min.y);
// Center
ImVec2 center = ImVec2((rect_min.x + rect_max.x) * 0.5f,
(rect_min.y + rect_max.y) * 0.5f);
// Check if point is inside
bool IsPointInRect(ImVec2 point, ImVec2 min, ImVec2 max)
{
return point.x >= min.x && point.x <= max.x &&
point.y >= min.y && point.y <= max.y;
}
```
## See Also
* [Colors](/api/colors) - Color utilities and conversion
* [Draw List](/api/draw-list) - Using vectors in drawing commands