/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "spritebatch.h"
#include "assert/assert.h"
#include "util/memory.h"

meshvertex_t SPRITEBATCH_VERTICES[SPRITEBATCH_VERTEX_COUNT];
spritebatch_t SPRITEBATCH;

void spriteBatchInit() {
  memoryZero(&SPRITEBATCH, sizeof(spritebatch_t));

  meshInit(
    &SPRITEBATCH.mesh,
    MESH_PRIMITIVE_TRIANGLES,
    SPRITEBATCH_VERTEX_COUNT,
    &SPRITEBATCH_VERTICES[0]
  );
}

void spriteBatchPush(
  texture_t *texture,
  const float_t minX,
  const float_t minY,
  const float_t maxX,
  const float_t maxY,
  const color_t color,
  const float_t u0,
  const float_t v0,
  const float_t u1,
  const float_t v1
) {
  return spriteBatchPush3D(
    texture,
    (vec3){ minX, minY, 0 },
    (vec3){ maxX, maxY, 0 },
    color,
    (vec2){ u0, v0 },
    (vec2){ u1, v1 }
  );
}

void spriteBatchPush3D(
  texture_t *texture,
  const vec3 min,
  const vec3 max,
  const color_t color,
  const vec2 uv0,
  const vec2 uv1
) {
  // Need to flush?
  if(
    SPRITEBATCH.currentTexture != texture ||
    SPRITEBATCH.spriteCount >= SPRITEBATCH_SPRITES_MAX
  ) {
    spriteBatchFlush();
    SPRITEBATCH.currentTexture = texture;
  }

  size_t vertexOffset = SPRITEBATCH.spriteCount * QUAD_VERTEX_COUNT;
  #if DOLPHIN
    vertexOffset += (
      SPRITEBATCH.batchIndex * SPRITEBATCH_SPRITES_MAX * QUAD_VERTEX_COUNT
    );
  #endif

  quadBuffer3D(
    &SPRITEBATCH_VERTICES[vertexOffset],
    min, max, color, uv0, uv1
  );
  SPRITEBATCH.spriteCount++;
}

void spriteBatchClear() {
  SPRITEBATCH.spriteCount = 0;
  SPRITEBATCH.currentTexture = NULL;
}

void spriteBatchFlush() {
  if(SPRITEBATCH.spriteCount == 0) return;
  textureBind(SPRITEBATCH.currentTexture);

  #if DOLPHIN
    meshDraw(
      &SPRITEBATCH.mesh,
      QUAD_VERTEX_COUNT * SPRITEBATCH.batchIndex * SPRITEBATCH_SPRITES_MAX,
      QUAD_VERTEX_COUNT * SPRITEBATCH.spriteCount
    );
    SPRITEBATCH.batchIndex = (
      (SPRITEBATCH.batchIndex + 1) % SPRITEBATCH_BATCH_COUNT
    );
  #else
    meshDraw(&SPRITEBATCH.mesh, 0, QUAD_VERTEX_COUNT * SPRITEBATCH.spriteCount);
  #endif
  spriteBatchClear();
}

void spriteBatchDispose() {
  meshDispose(&SPRITEBATCH.mesh);
}