#include <cogl/cogl.h>

#include <string.h>

#include "tests/cogl-test-utils.h"

#define QUAD_WIDTH 32

#define RED 0
#define GREEN 1
#define BLUE 2
#define ALPHA 3

#define MASK_RED(COLOR)   ((COLOR & 0xff000000) >> 24)
#define MASK_GREEN(COLOR) ((COLOR & 0xff0000) >> 16)
#define MASK_BLUE(COLOR)  ((COLOR & 0xff00) >> 8)
#define MASK_ALPHA(COLOR) (COLOR & 0xff)

typedef enum _MakeTextureFlags
{
  TEXTURE_FLAG_SET_PREMULTIPLIED = 1,
  TEXTURE_FLAG_SET_UNPREMULTIPLIED = 1<<1,
} MakeTextureFlags;

static guchar *
gen_tex_data (uint32_t color)
{
  guchar *tex_data, *p;
  uint8_t r = MASK_RED (color);
  uint8_t g = MASK_GREEN (color);
  uint8_t b = MASK_BLUE (color);
  uint8_t a = MASK_ALPHA (color);

  tex_data = g_malloc (QUAD_WIDTH * QUAD_WIDTH * 4);

  for (p = tex_data + QUAD_WIDTH * QUAD_WIDTH * 4; p > tex_data;)
    {
      *(--p) = a;
      *(--p) = b;
      *(--p) = g;
      *(--p) = r;
    }

  return tex_data;
}

static CoglTexture *
make_texture (uint32_t color,
	      CoglPixelFormat src_format,
              MakeTextureFlags flags)
{
  CoglTexture *tex;
  guchar *tex_data = gen_tex_data (color);
  CoglBitmap *bmp = cogl_bitmap_new_for_data (test_ctx,
                                              QUAD_WIDTH,
                                              QUAD_WIDTH,
                                              src_format,
                                              QUAD_WIDTH * 4,
                                              tex_data);

  tex = cogl_texture_2d_new_from_bitmap (bmp);

  if (flags & TEXTURE_FLAG_SET_PREMULTIPLIED)
    cogl_texture_set_premultiplied (tex, TRUE);
  else if (flags & TEXTURE_FLAG_SET_UNPREMULTIPLIED)
    cogl_texture_set_premultiplied (tex, FALSE);

  g_object_unref (bmp);

  return tex;
}

static void
set_region (CoglTexture *tex,
	    uint32_t color,
	    CoglPixelFormat format)
{
  guchar *tex_data = gen_tex_data (color);

  cogl_texture_set_region (tex,
                           0, 0, /* src x, y */
                           0, 0, /* dst x, y */
                           QUAD_WIDTH, QUAD_WIDTH, /* dst width, height */
                           QUAD_WIDTH, QUAD_WIDTH, /* src width, height */
                           format,
                           0, /* auto compute row stride */
                           tex_data);
}

static void
check_texture (CoglPipeline *pipeline,
	       int x,
	       int y,
	       CoglTexture *tex,
	       uint32_t expected_result)
{
  /* New API */
  cogl_pipeline_set_layer_texture (pipeline, 0, tex);
  cogl_framebuffer_draw_rectangle (test_fb, pipeline,
				   x * QUAD_WIDTH,
				   y * QUAD_WIDTH,
				   x * QUAD_WIDTH + QUAD_WIDTH,
				   y * QUAD_WIDTH + QUAD_WIDTH);
  test_utils_check_pixel (test_fb, x * QUAD_WIDTH + QUAD_WIDTH / 2, y * QUAD_WIDTH + QUAD_WIDTH / 2, expected_result);
}

static void
test_premult (void)
{
  CoglPipeline *pipeline;
  CoglTexture *tex;

  cogl_framebuffer_orthographic (test_fb, 0, 0,
				 cogl_framebuffer_get_width (test_fb),
				 cogl_framebuffer_get_height (test_fb),
				 -1,
				 100);

  cogl_framebuffer_clear4f (test_fb,
                            COGL_BUFFER_BIT_COLOR,
                            1.0f, 1.0f, 1.0f, 1.0f);

  /* New API */
  pipeline = cogl_pipeline_new (test_ctx);
  cogl_pipeline_set_blend (pipeline,
                           "RGBA = ADD (SRC_COLOR, 0)", NULL);
  cogl_pipeline_set_layer_combine (pipeline, 0,
                                   "RGBA = REPLACE (TEXTURE)", NULL);

  /* If the user explicitly specifies an unmultiplied internal format then
   * Cogl shouldn't automatically premultiply the given texture data... */
  if (cogl_test_verbose ())
    g_print ("make_texture (0xff00ff80, "
                            "src = RGBA_8888, internal = RGBA_8888)\n");
  tex = make_texture (0xff00ff80,
                      COGL_PIXEL_FORMAT_RGBA_8888, /* src format */
                      TEXTURE_FLAG_SET_UNPREMULTIPLIED);
  check_texture (pipeline, 0, 0, /* position */
		 tex,
		 0xff00ff80); /* expected */

  /* If the user explicitly requests a premultiplied internal format and
   * gives unmultiplied src data then Cogl should always premultiply that
   * for us */
  if (cogl_test_verbose ())
    g_print ("make_texture (0xff00ff80, "
                            "src = RGBA_8888, internal = RGBA_8888_PRE)\n");
  tex = make_texture (0xff00ff80,
                      COGL_PIXEL_FORMAT_RGBA_8888, /* src format */
                      TEXTURE_FLAG_SET_PREMULTIPLIED);
  check_texture (pipeline, 1, 0, /* position */
		 tex,
		 0x80008080); /* expected */

  /* If the user doesn't explicitly declare that the texture is premultiplied
   * then Cogl should assume it is by default should premultiply
   * unpremultiplied texture data...
   */
  if (cogl_test_verbose ())
    g_print ("make_texture (0xff00ff80, "
                            "src = RGBA_8888, internal = ANY)\n");
  tex = make_texture (0xff00ff80,
                      COGL_PIXEL_FORMAT_RGBA_8888, /* src format */
                      0); /* default premultiplied status */
  check_texture (pipeline, 2, 0, /* position */
		 tex,
		 0x80008080); /* expected */

  /* If the user requests a premultiplied internal texture format and supplies
   * premultiplied source data, Cogl should never modify that source data...
   */
  if (cogl_test_verbose ())
    g_print ("make_texture (0x80008080, "
                            "src = RGBA_8888_PRE, "
                            "internal = RGBA_8888_PRE)\n");
  tex = make_texture (0x80008080,
                      COGL_PIXEL_FORMAT_RGBA_8888_PRE, /* src format */
                      TEXTURE_FLAG_SET_PREMULTIPLIED);
  check_texture (pipeline, 3, 0, /* position */
		 tex,
		 0x80008080); /* expected */

  /* If the user requests an unmultiplied internal texture format, but
   * supplies premultiplied source data, then Cogl should always
   * un-premultiply the source data... */
  if (cogl_test_verbose ())
    g_print ("make_texture (0x80008080, "
                            "src = RGBA_8888_PRE, internal = RGBA_8888)\n");
  tex = make_texture (0x80008080,
                      COGL_PIXEL_FORMAT_RGBA_8888_PRE, /* src format */
                      TEXTURE_FLAG_SET_UNPREMULTIPLIED);
  check_texture (pipeline, 4, 0, /* position */
		 tex,
		 0xff00ff80); /* expected */

  /* If the user allows any internal texture format and provides premultipled
   * source data then by default Cogl shouldn't modify the source data...
   * (In the future there will be additional Cogl API to control this
   *  behaviour) */
  if (cogl_test_verbose ())
    g_print ("make_texture (0x80008080, "
                            "src = RGBA_8888_PRE, internal = ANY)\n");
  tex = make_texture (0x80008080,
                      COGL_PIXEL_FORMAT_RGBA_8888_PRE, /* src format */
                      0); /* default premultiplied status */
  check_texture (pipeline, 5, 0, /* position */
		 tex,
		 0x80008080); /* expected */

  /*
   * Test cogl_texture_set_region() ....
   */

  if (cogl_test_verbose ())
    g_print ("make_texture (0xDEADBEEF, "
                            "src = RGBA_8888, internal = RGBA_8888)\n");
  tex = make_texture (0xDEADBEEF,
                      COGL_PIXEL_FORMAT_RGBA_8888, /* src format */
                      TEXTURE_FLAG_SET_UNPREMULTIPLIED);
  if (cogl_test_verbose ())
    g_print ("set_region (0xff00ff80, RGBA_8888)\n");
  set_region (tex, 0xff00ff80, COGL_PIXEL_FORMAT_RGBA_8888);
  check_texture (pipeline, 6, 0, /* position */
		 tex,
		 0xff00ff80); /* expected */

  /* Updating a texture region for an unmultiplied texture using premultiplied
   * region data should result in Cogl unmultiplying the given region data...
   */
  if (cogl_test_verbose ())
    g_print ("make_texture (0xDEADBEEF, "
                            "src = RGBA_8888, internal = RGBA_8888)\n");
  tex = make_texture (0xDEADBEEF,
                      COGL_PIXEL_FORMAT_RGBA_8888, /* src format */
                      TEXTURE_FLAG_SET_UNPREMULTIPLIED);
  if (cogl_test_verbose ())
    g_print ("set_region (0x80008080, RGBA_8888_PRE)\n");
  set_region (tex, 0x80008080, COGL_PIXEL_FORMAT_RGBA_8888_PRE);
  check_texture (pipeline, 7, 0, /* position */
		 tex,
		 0xff00ff80); /* expected */


  if (cogl_test_verbose ())
    g_print ("make_texture (0xDEADBEEF, "
                            "src = RGBA_8888_PRE, "
                            "internal = RGBA_8888_PRE)\n");
  tex = make_texture (0xDEADBEEF,
                      COGL_PIXEL_FORMAT_RGBA_8888_PRE, /* src format */
                      TEXTURE_FLAG_SET_PREMULTIPLIED);
  if (cogl_test_verbose ())
    g_print ("set_region (0x80008080, RGBA_8888_PRE)\n");
  set_region (tex, 0x80008080, COGL_PIXEL_FORMAT_RGBA_8888_PRE);
  check_texture (pipeline, 8, 0, /* position */
		 tex,
		 0x80008080); /* expected */


  /* Updating a texture region for a premultiplied texture using unmultiplied
   * region data should result in Cogl premultiplying the given region data...
   */
  if (cogl_test_verbose ())
    g_print ("make_texture (0xDEADBEEF, "
                            "src = RGBA_8888_PRE, "
                            "internal = RGBA_8888_PRE)\n");
  tex = make_texture (0xDEADBEEF,
                      COGL_PIXEL_FORMAT_RGBA_8888_PRE, /* src format */
                      TEXTURE_FLAG_SET_PREMULTIPLIED);
  if (cogl_test_verbose ())
    g_print ("set_region (0xff00ff80, RGBA_8888)\n");
  set_region (tex, 0xff00ff80, COGL_PIXEL_FORMAT_RGBA_8888);
  check_texture (pipeline, 9, 0, /* position */
		 tex,
		 0x80008080); /* expected */


  if (cogl_test_verbose ())
    g_print ("OK\n");
}

COGL_TEST_SUITE (
  g_test_add_func ("/premult", test_premult);
)
