#include "quakedef.h"
#include "r_shadow.h"

extern cvar_t r_labelsprites_scale;
extern cvar_t r_labelsprites_roundtopixels;

void R_Model_Sprite_Draw_TransparentCallback(const entity_render_t *ent, const rtlight_t *rtlight, int numsurfaces, int *surfacelist)
{
	int i;
	model_t *model = ent->model;
	vec3_t left, up, org, mforward, mleft, mup, middle;
	float scale, dx, dy, hud_vs_screen;

	// nudge it toward the view to make sure it isn't in a wall
	Matrix4x4_ToVectors(&ent->matrix, mforward, mleft, mup, org);
	VectorSubtract(org, r_view.forward, org);
	switch(model->sprite.sprnum_type)
	{
	case SPR_VP_PARALLEL_UPRIGHT:
		// flames and such
		// vertical beam sprite, faces view plane
		scale = ent->scale / sqrt(r_view.forward[0]*r_view.forward[0]+r_view.forward[1]*r_view.forward[1]);
		left[0] = -r_view.forward[1] * scale;
		left[1] = r_view.forward[0] * scale;
		left[2] = 0;
		up[0] = 0;
		up[1] = 0;
		up[2] = ent->scale;
		break;
	case SPR_FACING_UPRIGHT:
		// flames and such
		// vertical beam sprite, faces viewer's origin (not the view plane)
		scale = ent->scale / sqrt((org[0] - r_view.origin[0])*(org[0] - r_view.origin[0])+(org[1] - r_view.origin[1])*(org[1] - r_view.origin[1]));
		left[0] = (org[1] - r_view.origin[1]) * scale;
		left[1] = -(org[0] - r_view.origin[0]) * scale;
		left[2] = 0;
		up[0] = 0;
		up[1] = 0;
		up[2] = ent->scale;
		break;
	default:
		Con_Printf("R_SpriteSetup: unknown sprite type %i\n", model->sprite.sprnum_type);
		// fall through to normal sprite
	case SPR_VP_PARALLEL:
		// normal sprite
		// faces view plane
		VectorScale(r_view.left, ent->scale, left);
		VectorScale(r_view.up, ent->scale, up);
		break;
	case SPR_LABEL_SCALE:
		// normal sprite
		// faces view plane
		// fixed HUD pixel size specified in sprite
		// honors scale
		// honors a global label scaling cvar

		scale = 2 * ent->scale * (DotProduct(r_view.forward, org) - DotProduct(r_view.forward, r_view.origin)) * r_labelsprites_scale.value;
		VectorScale(r_view.left, scale * r_view.frustum_x / vid_conwidth.integer, left); // 1px
		VectorScale(r_view.up, scale * r_view.frustum_y / vid_conheight.integer, up); // 1px
		break;
	case SPR_LABEL:
		// normal sprite
		// faces view plane
		// fixed pixel size specified in sprite
		// tries to get the right size in HUD units, if possible
		// ignores scale
		// honors a global label scaling cvar before the rounding
		// FIXME assumes that 1qu is 1 pixel in the sprite like in SPR32 format. Should not do that, but instead query the source image! This bug only applies to the roundtopixels case, though.

		scale = 2 * (DotProduct(r_view.forward, org) - DotProduct(r_view.forward, r_view.origin));

		if(r_labelsprites_roundtopixels.integer)
		{
			hud_vs_screen = max(
				vid_conwidth.integer / (float) r_view.width,
				vid_conheight.integer / (float) r_view.height
			) / max(0.125, r_labelsprites_scale.value);

			// snap to "good sizes"
			// 1     for (0.6, 1.41]
			// 2     for (1.8, 3.33]
			if(hud_vs_screen <= 0.6)
				hud_vs_screen = 0; // don't, use real HUD pixels
			else if(hud_vs_screen <= 1.41)
				hud_vs_screen = 1;
			else if(hud_vs_screen <= 3.33)
				hud_vs_screen = 2;
			else
				hud_vs_screen = 0; // don't, use real HUD pixels

			if(hud_vs_screen)
			{
				// use screen pixels
				VectorScale(r_view.left, scale * r_view.frustum_x / (r_view.width * hud_vs_screen), left); // 1px
				VectorScale(r_view.up, scale * r_view.frustum_y / (r_view.height * hud_vs_screen), up); // 1px
			}
			else
			{
				// use HUD pixels
				VectorScale(r_view.left, scale * r_view.frustum_x / vid_conwidth.integer * r_labelsprites_scale.value, left); // 1px
				VectorScale(r_view.up, scale * r_view.frustum_y / vid_conheight.integer * r_labelsprites_scale.value, up); // 1px
			}

			if(hud_vs_screen == 1)
			{
				VectorMA(r_view.origin, scale, r_view.forward, middle); // center of screen in distance scale
				dx = 0.5 - fmod(r_view.width * 0.5 + (DotProduct(org, left) - DotProduct(middle, left)) / DotProduct(left, left) + 0.5, 1.0);
				dy = 0.5 - fmod(r_view.height * 0.5 + (DotProduct(org, up) - DotProduct(middle, up)) / DotProduct(up, up) + 0.5, 1.0);
				VectorMAMAM(1, org, dx, left, dy, up, org);
			}
		}
		else
		{
			// use HUD pixels
			VectorScale(r_view.left, scale * r_view.frustum_x / vid_conwidth.integer * r_labelsprites_scale.value, left); // 1px
			VectorScale(r_view.up, scale * r_view.frustum_y / vid_conheight.integer * r_labelsprites_scale.value, up); // 1px
		}
		break;
	case SPR_ORIENTED:
		// bullet marks on walls
		// ignores viewer entirely
		VectorCopy(mleft, left);
		VectorCopy(mup, up);
		break;
	case SPR_VP_PARALLEL_ORIENTED:
		// I have no idea what people would use this for...
		// oriented relative to view space
		// FIXME: test this and make sure it mimicks software
		left[0] = mleft[0] * r_view.forward[0] + mleft[1] * r_view.left[0] + mleft[2] * r_view.up[0];
		left[1] = mleft[0] * r_view.forward[1] + mleft[1] * r_view.left[1] + mleft[2] * r_view.up[1];
		left[2] = mleft[0] * r_view.forward[2] + mleft[1] * r_view.left[2] + mleft[2] * r_view.up[2];
		up[0] = mup[0] * r_view.forward[0] + mup[1] * r_view.left[0] + mup[2] * r_view.up[0];
		up[1] = mup[0] * r_view.forward[1] + mup[1] * r_view.left[1] + mup[2] * r_view.up[1];
		up[2] = mup[0] * r_view.forward[2] + mup[1] * r_view.left[2] + mup[2] * r_view.up[2];
		break;
	}

	R_Mesh_Matrix(&identitymatrix);

	// LordHavoc: interpolated sprite rendering
	for (i = 0;i < 4;i++)
	{
		if (ent->frameblend[i].lerp >= 0.01f)
		{
			mspriteframe_t *frame = model->sprite.sprdata_frames + ent->frameblend[i].frame;
			texture_t *texture = model->data_textures + ent->frameblend[i].frame;
			R_UpdateTextureInfo(ent, texture);
			// FIXME: negate left and right in loader
			R_DrawSprite(texture->currentlayers[0].blendfunc1, texture->currentlayers[0].blendfunc2, texture->basetexture, texture->currentskinframe->fog, (texture->currentmaterialflags & MATERIALFLAG_NODEPTHTEST), (texture->currentmaterialflags & MATERIALFLAG_SHORTDEPTHRANGE), org, left, up, frame->left, frame->right, frame->down, frame->up, texture->currentlayers[0].color[0], texture->currentlayers[0].color[1], texture->currentlayers[0].color[2], ent->alpha * ent->frameblend[i].lerp);
		}
	}
}

void R_Model_Sprite_Draw(entity_render_t *ent)
{
	vec3_t org;
	if (ent->frameblend[0].frame < 0)
		return;

	Matrix4x4_OriginFromMatrix(&ent->matrix, org);
	R_MeshQueue_AddTransparent(ent->effects & EF_NODEPTHTEST ? r_view.origin : org, R_Model_Sprite_Draw_TransparentCallback, ent, 0, rsurface.rtlight);
}