hgeSprite::SetHotSpot

Set the rotation and positioning center point for a sprite.

Synopsis

void hgeSprite::SetHotSpot(float x, float y);

Parameters

x — X coordinate of the hot spot relative to sprite's left edge
y — Y coordinate of the hot spot relative to sprite's top edge

Description

The hot spot defines the sprite's anchor point for positioning and rotation. When you call Render(px, py), the hot spot is placed at (px, py). When you rotate the sprite, it rotates around the hot spot.

Default Value

By default, the hot spot is at (0, 0) — the top-left corner of the sprite.

Common Patterns

Center Hot Spot

For sprites that rotate around their center:

hgeSprite *spr = new hgeSprite(tex, 0, 0, 64, 64);
spr->SetHotSpot(32, 32);  // Center of 64x64 sprite

Bottom-Center for Characters

For standing characters where (x, y) represents their feet position:

hgeSprite *character = new hgeSprite(tex, 0, 0, 32, 64);
character->SetHotSpot(16, 64);  // Bottom center

Top-Left for UI

For UI elements where (x, y) is the top-left corner (default behavior):

hgeSprite *button = new hgeSprite(tex, 0, 0, 100, 30);
// Hot spot defaults to (0, 0), no change needed

Example

// Create a rotating enemy sprite
hgeSprite *enemy = new hgeSprite(texEnemy, 0, 0, 48, 48);
enemy->SetHotSpot(24, 24);  // Center

float rotation = 0;

bool FrameFunc()
{
    float dt = hge->Timer_GetDelta();
    rotation += 2.0f * dt;  // Rotate over time
    return false;
}

bool RenderFunc()
{
    hge->Gfx_BeginScene();
    enemy->RenderEx(400, 300, rotation);  // Rotates around center
    hge->Gfx_EndScene();
    return false;
}