O2048/zephr/texture.odin

package zephr

import gl "vendor:OpenGL"
import stb "vendor:stb/image"

TextureId :: u32

load_texture :: proc(path: cstring) -> TextureId {
  texture_id: TextureId;
  width, height, channels: i32
  data := stb.load(path, &width, &height, &channels, 4) // RGBA
  defer stb.image_free(data)

  format := gl.RGBA;

  switch (channels) {
    case 1:
      format = gl.RED;
      break;
    case 2:
      format = gl.RG;
      break;
    case 3:
      format = gl.RGB;
      break;
    case 4:
      format = gl.RGBA;
      break;
  }

  gl.GenTextures(1, &texture_id);
  gl.BindTexture(gl.TEXTURE_2D, texture_id);

  gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
  gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);

  gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR);
  gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);

  gl.TexImage2D(gl.TEXTURE_2D, 0, cast(i32)format, width, height, 0, cast(u32)format, gl.UNSIGNED_BYTE, data);

  gl.GenerateMipmap(gl.TEXTURE_2D);

  return texture_id;
}