#include "config.h"

#include "gskgpulineargradientopprivate.h"

#include "gskgpuframeprivate.h"
#include "gskgpuprintprivate.h"
#include "gskrectprivate.h"

#include "gpu/shaders/gskgpulineargradientinstance.h"

#define VARIATION_SUPERSAMPLING (1 << 0)
#define VARIATION_REPEATING     (1 << 1)

typedef struct _GskGpuLinearGradientOp GskGpuLinearGradientOp;

struct _GskGpuLinearGradientOp
{
  GskGpuShaderOp op;
};

static void
gsk_gpu_linear_gradient_op_print (GskGpuOp    *op,
                                  GskGpuFrame *frame,
                                  GString     *string,
                                  guint        indent)
{
  GskGpuShaderOp *shader = (GskGpuShaderOp *) op;
  GskGpuLineargradientInstance *instance;

  instance = (GskGpuLineargradientInstance *) gsk_gpu_frame_get_vertex_data (frame, shader->vertex_offset);

  if (shader->variation & VARIATION_REPEATING)
    gsk_gpu_print_op (string, indent, "repeating-linear-gradient");
  else
    gsk_gpu_print_op (string, indent, "linear-gradient");
  gsk_gpu_print_shader_info (string, shader->clip);
  gsk_gpu_print_rect (string, instance->rect);
  gsk_gpu_print_newline (string);
}

static const GskGpuShaderOpClass GSK_GPU_LINEAR_GRADIENT_OP_CLASS = {
  {
    GSK_GPU_OP_SIZE (GskGpuLinearGradientOp),
    GSK_GPU_STAGE_SHADER,
    gsk_gpu_shader_op_finish,
    gsk_gpu_linear_gradient_op_print,
#ifdef GDK_RENDERING_VULKAN
    gsk_gpu_shader_op_vk_command,
#endif
    gsk_gpu_shader_op_gl_command
  },
  "gskgpulineargradient",
  sizeof (GskGpuLineargradientInstance),
#ifdef GDK_RENDERING_VULKAN
  &gsk_gpu_lineargradient_info,
#endif
  gsk_gpu_lineargradient_setup_attrib_locations,
  gsk_gpu_lineargradient_setup_vao
};

void
gsk_gpu_linear_gradient_op (GskGpuFrame            *frame,
                            GskGpuShaderClip        clip,
                            gboolean                repeating,
                            const graphene_rect_t  *rect,
                            const graphene_point_t *start,
                            const graphene_point_t *end,
                            const graphene_point_t *offset,
                            const GskColorStop     *stops,
                            gsize                   n_stops)
{
  GskGpuLineargradientInstance *instance;

  g_assert (n_stops > 1);
  g_assert (n_stops <= 7);

  gsk_gpu_shader_op_alloc (frame,
                           &GSK_GPU_LINEAR_GRADIENT_OP_CLASS,
                           (repeating ? VARIATION_REPEATING : 0) |
                           (gsk_gpu_frame_should_optimize (frame, GSK_GPU_OPTIMIZE_GRADIENTS) ? VARIATION_SUPERSAMPLING : 0),
                           clip,
                           NULL,
                           &instance);

  gsk_gpu_rect_to_float (rect, offset, instance->rect);
  gsk_gpu_point_to_float (start, offset, instance->startend);
  gsk_gpu_point_to_float (end, offset, &instance->startend[2]);
  gsk_gpu_rgba_to_float (&stops[MIN (n_stops - 1, 6)].color, instance->color6);
  instance->offsets1[2] = stops[MIN (n_stops - 1, 6)].offset;
  gsk_gpu_rgba_to_float (&stops[MIN (n_stops - 1, 5)].color, instance->color5);
  instance->offsets1[1] = stops[MIN (n_stops - 1, 5)].offset;
  gsk_gpu_rgba_to_float (&stops[MIN (n_stops - 1, 4)].color, instance->color4);
  instance->offsets1[0] = stops[MIN (n_stops - 1, 4)].offset;
  gsk_gpu_rgba_to_float (&stops[MIN (n_stops - 1, 3)].color, instance->color3);
  instance->offsets0[3] = stops[MIN (n_stops - 1, 3)].offset;
  gsk_gpu_rgba_to_float (&stops[MIN (n_stops - 1, 2)].color, instance->color2);
  instance->offsets0[2] = stops[MIN (n_stops - 1, 2)].offset;
  gsk_gpu_rgba_to_float (&stops[1].color, instance->color1);
  instance->offsets0[1] = stops[1].offset;
  gsk_gpu_rgba_to_float (&stops[0].color, instance->color0);
  instance->offsets0[0] = stops[0].offset;
}
