Modules/game pawn

The game_pawn module handle character animation, rendering, collision and physics.

This module offer several structures the user can use to configure a pawn (a player, an enemy or any moving object) for rendering (multi-layers and flip/flap) and movement.

Dependencies

• vdp
• memory

Settings

• GAMEPAWN_USE_PHYSICS: Include collision and physics handling functions.

Usage

Define pawn's sprites

The visual of a pawn is defined by one or more sprite layers. The Game_Sprite structure allows to define the parameters of each layer : The X/Y position of the layer relative to the Pawn, the pattern number offset from the pattern number defined in the animation, the sprite color and a special flag for display.

Examples:

Simple color sprite (1 layer): ‎

const Game_Sprite g_SpriteLayers[] =
{
	{ 0, 0, 0,  COLOR_WHITE, 0 }, // Sprite position offset: 0,0. Pattern offset: 0. Color: White. No special flag
};
‎

Two color sprite (2 layer): ‎

const Game_Sprite g_SpriteLayers[] =
{
	{ 0, 0, 0,  COLOR_WHITE, 0 }, // Sprite position offset: 0,0. Pattern offset: 0. Color: White. No special flag
	{ 0, -8, 4,  COLOR_GRAY, 0 }, // Sprite position offset: 0,-8. Pattern offset: 4. Color: Gray. No special flag
};
‎

3 layers sprite with auto-switching (to generate more color by flickering) ‎

const Game_Sprite g_SpriteLayers[] =
{
	{ 0, 0, 0,  COLOR_BLACK, PAWN_SPRITE_EVEN }, // Sprite used only on 'even' frame number
	{ 0, 0, 12, COLOR_BLACK, PAWN_SPRITE_ODD }, // Sprite used only on 'odd' frame number
	{ 0, 0, 4,  COLOR_WHITE, 0 },
	{ 0, 0, 8,  COLOR_LIGHT_RED, 0 },
};
‎

Define pawn's animations

Each animation is defined by a list of Game_Frame structures that determine : The pattern number of the animation, the duration of the frame in number of display cycles, and a function to call when the character reach a given frame of the animation.

Examples:

Push animation with function to trigger ‎

const Game_Frame g_FramePunch[] =
{
	{ 0,	4,	null }, // Display pattern 0 for 4 render cycles
	{ 8,	4,	null },
	{ 8,	1,	DoPunch }, // call function DoPunch() when Pawn is displaying this frame
	{ 24,	4,	null },
	{ 32,	4,	null },
};
‎

Annexe

• See also : Sample program s_game