// Drawing primitives.
//
// All primitives clip to the surface rectangle. Out-of-bounds draws are
// silent no-ops, not errors. samplePixel returns 0 for off-surface reads.
// Primitives operate on color indices; per-scanline palette resolution
// happens only at display time.

#ifndef JOEYLIB_DRAW_H
#define JOEYLIB_DRAW_H

#include "asset.h"
#include "platform.h"
#include "surface.h"
#include "types.h"

// Fill the entire surface with a single color index. Writes color 0 is
// a legitimate clear-to-black and does not skip.
void surfaceClear(SurfaceT *s, uint8_t colorIndex);

// Plot a single pixel. Off-surface coordinates are no-ops.
void drawPixel(SurfaceT *s, int16_t x, int16_t y, uint8_t colorIndex);

// Read a pixel value. Off-surface coordinates return 0.
uint8_t samplePixel(const SurfaceT *s, int16_t x, int16_t y);

// Fill a solid rectangle. Negative or zero dimensions are no-ops.
void fillRect(SurfaceT *s, int16_t x, int16_t y, uint16_t w, uint16_t h, uint8_t colorIndex);

// Blit an asset onto the surface at (x, y). Source nibbles overwrite
// destination nibbles verbatim -- the caller is responsible for
// matching the asset's palette to the destination palette (typically
// via joeyAssetApplyPalette). Clipped to the surface; off-surface
// rows / columns are skipped.
void surfaceBlit(SurfaceT *dst, const JoeyAssetT *src, int16_t x, int16_t y);

// Like surfaceBlit, but source pixels equal to transparentIndex are
// skipped, leaving the destination pixel unchanged at that position.
// The standard convention is transparentIndex = 0.
void surfaceBlitMasked(SurfaceT *dst, const JoeyAssetT *src, int16_t x, int16_t y, uint8_t transparentIndex);

#endif