/**
 * $Id:
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The Original Code is Copyright (C) 2009 Blender Foundation.
 * All rights reserved.
 *
 * 
 * Contributor(s): Blender Foundation
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include <ft2build.h>

#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_OUTLINE_H

#include "MEM_guardedalloc.h"

#include "DNA_listBase.h"
#include "DNA_vec_types.h"

#include "BKE_utildefines.h"

#include "BLI_blenlib.h"
#include "BLI_linklist.h"	/* linknode */
#include "BLI_string.h"

#include "BIF_gl.h"
#include "BLF_api.h"

#include "blf_internal_types.h"
#include "blf_internal.h"


GlyphCacheBLF *blf_glyph_cache_find(FontBLF *font, int size, int dpi)
{
	GlyphCacheBLF *p;

	p= (GlyphCacheBLF *)font->cache.first;
	while (p) {
		if (p->size == size && p->dpi == dpi)
			return(p);
		p= p->next;
	}
	return(NULL);
}

/* Create a new glyph cache for the current size and dpi. */
GlyphCacheBLF *blf_glyph_cache_new(FontBLF *font)
{
	GlyphCacheBLF *gc;
	int i;

	gc= (GlyphCacheBLF *)MEM_mallocN(sizeof(GlyphCacheBLF), "blf_glyph_cache_new");
	gc->next= NULL;
	gc->prev= NULL;
	gc->size= font->size;
	gc->dpi= font->dpi;

	for (i= 0; i < 257; i++) {
		gc->bucket[i].first= NULL;
		gc->bucket[i].last= NULL;
	}

	gc->textures= (GLuint *)malloc(sizeof(GLuint)*256);
	gc->ntex= 256;
	gc->cur_tex= -1;
	gc->x_offs= 0;
	gc->y_offs= 0;
	gc->pad= 3;

	gc->num_glyphs= font->face->num_glyphs;
	gc->rem_glyphs= font->face->num_glyphs;
	gc->ascender= ((float)font->face->size->metrics.ascender) / 64.0f;
	gc->descender= ((float)font->face->size->metrics.descender) / 64.0f;

	if (FT_IS_SCALABLE(font->face)) {
		gc->max_glyph_width= (float)((font->face->bbox.xMax - font->face->bbox.xMin) *
					(((float)font->face->size->metrics.x_ppem) /
					 ((float)font->face->units_per_EM)));

		gc->max_glyph_height= (float)((font->face->bbox.yMax - font->face->bbox.yMin) *
					(((float)font->face->size->metrics.y_ppem) /
					 ((float)font->face->units_per_EM)));
	}
	else {
		gc->max_glyph_width= ((float)font->face->size->metrics.max_advance) / 64.0f;
		gc->max_glyph_height= ((float)font->face->size->metrics.height) / 64.0f;
	}

	gc->p2_width= 0;
	gc->p2_height= 0;

	BLI_addhead(&font->cache, gc);
	return(gc);
}

void blf_glyph_cache_free(GlyphCacheBLF *gc)
{
	GlyphBLF *g;
	int i;

	for (i= 0; i < 257; i++) {
		while (gc->bucket[i].first) {
			g= gc->bucket[i].first;
			BLI_remlink(&(gc->bucket[i]), g);
			blf_glyph_free(g);
		}
	}

	glDeleteTextures(gc->cur_tex+1, gc->textures);
	free((void *)gc->textures);
	MEM_freeN(gc);
}

void blf_glyph_cache_texture(FontBLF *font, GlyphCacheBLF *gc)
{
	int tot_mem, i;
	unsigned char *buf;

	/* move the index. */
	gc->cur_tex++;

	if (gc->cur_tex >= gc->ntex) {
		gc->ntex *= 2;
		gc->textures= (GLuint *)realloc((void *)gc->textures, sizeof(GLuint)*gc->ntex);
	}

	gc->p2_width= blf_next_p2((gc->rem_glyphs * gc->max_glyph_width) + (gc->pad * 2));
	if (gc->p2_width > font->max_tex_size)
		gc->p2_width= font->max_tex_size;

	i= (int)((gc->p2_width - (gc->pad * 2)) / gc->max_glyph_width);
	gc->p2_height= blf_next_p2(((gc->num_glyphs / i) + 1) * gc->max_glyph_height);

	if (gc->p2_height > font->max_tex_size)
		gc->p2_height= font->max_tex_size;

	tot_mem= gc->p2_width * gc->p2_height;
	buf= (unsigned char *)malloc(tot_mem);
	memset((void *)buf, 0, tot_mem);

	glGenTextures(1, &gc->textures[gc->cur_tex]);
	glBindTexture(GL_TEXTURE_2D, gc->textures[gc->cur_tex]);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gc->p2_width, gc->p2_height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, buf);
	free((void *)buf);
}

GlyphBLF *blf_glyph_search(GlyphCacheBLF *gc, unsigned int c)
{
	GlyphBLF *p;
	unsigned int key;

	key= blf_hash(c);
	p= gc->bucket[key].first;
	while (p) {
		if (p->c == c)
			return(p);
		p= p->next;
	}
	return(NULL);
}

GlyphBLF *blf_glyph_texture_add(FontBLF *font, FT_UInt index, unsigned int c)
{
	FT_GlyphSlot slot;
	GlyphCacheBLF *gc;
	GlyphBLF *g;
	GlyphTextureBLF *gt;
	FT_Error err;
	FT_Bitmap bitmap;
	FT_BBox bbox;
	unsigned int key;
	int do_new;

	g= blf_glyph_search(font->glyph_cache, c);

	/* The glyph can be add on Bitmap mode, so we have the
	 * glyph, but not the texture data.
	 */
	if (g && g->tex_data)
		return(g);
	else if (g)
		do_new= 0;
	else
		do_new= 1;

	err= FT_Load_Glyph(font->face, index, FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP);
	if (err)
		return(NULL);

	/* get the glyph. */
	slot= font->face->glyph;

	err= FT_Render_Glyph(slot, FT_RENDER_MODE_NORMAL);
	if (err || slot->format != FT_GLYPH_FORMAT_BITMAP)
		return(NULL);

	if (do_new) {
		g= (GlyphBLF *)MEM_mallocN(sizeof(GlyphBLF), "blf_glyph_add");
		g->next= NULL;
		g->prev= NULL;
		g->tex_data= NULL;
		g->bitmap_data= NULL;
		g->c= c;
	}

	gt= (GlyphTextureBLF *)MEM_mallocN(sizeof(GlyphTextureBLF), "blf_glyph_texture_add");
	gc= font->glyph_cache;

	if (gc->cur_tex == -1) {
		blf_glyph_cache_texture(font, gc);
		gc->x_offs= gc->pad;
		gc->y_offs= gc->pad;
	}

	if (gc->x_offs > (gc->p2_width - gc->max_glyph_width)) {
		gc->x_offs= gc->pad;
		gc->y_offs += gc->max_glyph_height;

		if (gc->y_offs > (gc->p2_height - gc->max_glyph_height)) {
			gc->y_offs= gc->pad;
			blf_glyph_cache_texture(font, gc);
		}
	}

	bitmap= slot->bitmap;
	gt->tex= gc->textures[gc->cur_tex];

	gt->xoff= gc->x_offs;
	gt->yoff= gc->y_offs;
	gt->width= bitmap.width;
	gt->height= bitmap.rows;

	if (gt->width && gt->height) {
		glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
		glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE);
		glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
		glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

		glBindTexture(GL_TEXTURE_2D, gt->tex);
		glTexSubImage2D(GL_TEXTURE_2D, 0, gt->xoff, gt->yoff, gt->width, gt->height, GL_ALPHA, GL_UNSIGNED_BYTE, bitmap.buffer);
		glPopClientAttrib();
	}

	g->advance= ((float)slot->advance.x) / 64.0f;
	gt->pos_x= slot->bitmap_left;
	gt->pos_y= slot->bitmap_top;

	FT_Outline_Get_CBox(&(slot->outline), &bbox);
	g->box.xmin= ((float)bbox.xMin) / 64.0f;
	g->box.xmax= ((float)bbox.xMax) / 64.0f;
	g->box.ymin= ((float)bbox.yMin) / 64.0f;
	g->box.ymax= ((float)bbox.yMax) / 64.0f;

	gt->uv[0][0]= ((float)gt->xoff) / ((float)gc->p2_width);
	gt->uv[0][1]= ((float)gt->yoff) / ((float)gc->p2_height);
	gt->uv[1][0]= ((float)(gt->xoff + gt->width)) / ((float)gc->p2_width);
	gt->uv[1][1]= ((float)(gt->yoff + gt->height)) / ((float)gc->p2_height);

	/* update the x offset for the next glyph. */
	gc->x_offs += (int)(g->box.xmax - g->box.xmin + gc->pad);

	if (do_new) {
		key= blf_hash(g->c);
		BLI_addhead(&(gc->bucket[key]), g);
		gc->rem_glyphs--;
	}

	/* and attach the texture information. */
	g->tex_data= gt;

	return(g);
}

GlyphBLF *blf_glyph_bitmap_add(FontBLF *font, FT_UInt index, unsigned int c)
{
	FT_GlyphSlot slot;
	GlyphCacheBLF *gc;
	GlyphBLF *g;
	GlyphBitmapBLF *gt;
	FT_Error err;
	FT_Bitmap bitmap;
	FT_BBox bbox;
	unsigned char *dest, *src;
	unsigned int key, y;
	unsigned int src_width, src_height, src_pitch;
	int do_new;

	g= blf_glyph_search(font->glyph_cache, c);

	/*
	 * The glyph can be add on Texture mode, so we have the
	 * glyph, but not the bitmap data.
	 */
	if (g && g->bitmap_data)
		return(g);
	else if (g)
		do_new= 0;
	else
		do_new= 1;

	err= FT_Load_Glyph(font->face, index, FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP);
	if (err)
		return(NULL);

	/* get the glyph. */
	slot= font->face->glyph;

	err= FT_Render_Glyph(slot, FT_RENDER_MODE_MONO);
	if (err || slot->format != FT_GLYPH_FORMAT_BITMAP)
		return(NULL);

	if (do_new) {
		g= (GlyphBLF *)MEM_mallocN(sizeof(GlyphBLF), "blf_glyph_add");
		g->next= NULL;
		g->prev= NULL;
		g->tex_data= NULL;
		g->bitmap_data= NULL;
		g->c= c;
	}

	gt= (GlyphBitmapBLF *)MEM_mallocN(sizeof(GlyphBitmapBLF), "blf_glyph_bitmap_add");
	gc= font->glyph_cache;

	bitmap= slot->bitmap;

	src_width= bitmap.width;
	src_height= bitmap.rows;
	src_pitch= bitmap.pitch;

	gt->width= src_width;
	gt->height= src_height;
	gt->pitch= src_pitch;
	gt->image= NULL;

	if (gt->width && gt->height) {
		gt->image= (unsigned char *)malloc(gt->pitch * gt->height);

		dest= gt->image + ((gt->height - 1) * gt->pitch);
		src= bitmap.buffer;

		for (y= 0; y < src_height; ++y) {
			memcpy((void *)dest, (void *)src, src_pitch);
			dest -= gt->pitch;
			src += src_pitch;
		}
	}

	g->advance= ((float)slot->advance.x) / 64.0f;
	gt->pos_x= slot->bitmap_left;
	gt->pos_y= ((int)src_height) - slot->bitmap_top;

	FT_Outline_Get_CBox(&(slot->outline), &bbox);
	g->box.xmin= ((float)bbox.xMin) / 64.0f;
	g->box.xmax= ((float)bbox.xMax) / 64.0f;
	g->box.ymin= ((float)bbox.yMin) / 64.0f;
	g->box.ymax= ((float)bbox.yMax) / 64.0f;

	if (do_new) {
		key= blf_hash(g->c);
		BLI_addhead(&(gc->bucket[key]), g);
		gc->rem_glyphs--;
	}

	/* and attach the bitmap information. */
	g->bitmap_data= gt;

	return(g);
}

GlyphBLF *blf_glyph_add(FontBLF *font, FT_UInt index, unsigned int c)
{
	if (font->mode == BLF_MODE_BITMAP)
		return(blf_glyph_bitmap_add(font, index, c));
	return(blf_glyph_texture_add(font, index, c));
}

void blf_glyph_free(GlyphBLF *g)
{
	if (g->tex_data)
		MEM_freeN(g->tex_data);

	if (g->bitmap_data) {
		if (g->bitmap_data->image)
			free((void *)g->bitmap_data->image);
		MEM_freeN(g->bitmap_data);
	}

	/* don't need free the texture, the GlyphCache already
	 * have a list of all the texture and free it.
	 */
	MEM_freeN(g);
}

static void blf_texture_draw(float uv[2][2], float dx, float y1, float dx1, float y2)
{
	
	glBegin(GL_QUADS);
	glTexCoord2f(uv[0][0], uv[0][1]);
	glVertex2f(dx, y1);
	
	glTexCoord2f(uv[0][0], uv[1][1]);
	glVertex2f(dx, y2);
	
	glTexCoord2f(uv[1][0], uv[1][1]);
	glVertex2f(dx1, y2);
	
	glTexCoord2f(uv[1][0], uv[0][1]);
	glVertex2f(dx1, y1);
	glEnd();
	
}

static void blf_texture5_draw(float uv[2][2], float x1, float y1, float x2, float y2)
{
	float soft[25]= {
		1/60.0f, 1/60.0f, 2/60.0f, 1/60.0f, 1/60.0f, 
		1/60.0f, 3/60.0f, 5/60.0f, 3/60.0f, 1/60.0f, 
		2/60.0f, 5/60.0f, 8/60.0f, 5/60.0f, 2/60.0f, 
		1/60.0f, 3/60.0f, 5/60.0f, 3/60.0f, 1/60.0f, 
		1/60.0f, 1/60.0f, 2/60.0f, 1/60.0f, 1/60.0f};
	
	float color[4], *fp= soft;
	int dx, dy;
	
	glGetFloatv(GL_CURRENT_COLOR, color);
	
	for(dx=-2; dx<3; dx++) {
		for(dy=-2; dy<3; dy++, fp++) {
			glColor4f(color[0], color[1], color[2], fp[0]*color[3]);
			blf_texture_draw(uv, x1+dx, y1+dy, x2+dx, y2+dy);
		}
	}
	
	glColor4fv(color);
}

static void blf_texture3_draw(float uv[2][2], float x1, float y1, float x2, float y2)
{
	float soft[9]= {1/16.0f, 2/16.0f, 1/16.0f, 2/16.0f, 4/16.0f, 2/16.0f, 1/16.0f, 2/16.0f, 1/16.0f};
	float color[4], *fp= soft;
	int dx, dy;
	
	glGetFloatv(GL_CURRENT_COLOR, color);
	
	for(dx=-1; dx<2; dx++) {
		for(dy=-1; dy<2; dy++, fp++) {
			glColor4f(color[0], color[1], color[2], fp[0]*color[3]);
			blf_texture_draw(uv, x1+dx, y1+dy, x2+dx, y2+dy);
		}
	}
	
	glColor4fv(color);
}

int blf_glyph_texture_render(FontBLF *font, GlyphBLF *g, float x, float y)
{
	GlyphTextureBLF *gt;
	GLint cur_tex;
	float dx, dx1;
	float y1, y2;
	float xo, yo;
	float color[4];

	gt= g->tex_data;
	xo= 0.0f;
	yo= 0.0f;

	if (font->flags & BLF_SHADOW) {
		xo= x;
		yo= y;
		x += font->shadow_x;
		y += font->shadow_y;
	}

	dx= floor(x + gt->pos_x);
	dx1= dx + gt->width;
	y1= y + gt->pos_y;
	y2= y + gt->pos_y - gt->height;

	if (font->flags & BLF_CLIPPING) {
		if (!BLI_in_rctf(&font->clip_rec, dx + font->pos[0], y1 + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, dx + font->pos[0], y2 + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, dx1 + font->pos[0], y2 + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, dx1 + font->pos[0], y1 + font->pos[1]))
			return(0);
	}

	glGetIntegerv(GL_TEXTURE_2D_BINDING_EXT, &cur_tex);
	if (cur_tex != gt->tex)
		glBindTexture(GL_TEXTURE_2D, gt->tex);

	if (font->flags & BLF_SHADOW) {
		glGetFloatv(GL_CURRENT_COLOR, color);
		glColor4fv(font->shadow_col);

		if (font->shadow == 3)
			blf_texture3_draw(gt->uv, dx, y1, dx1, y2);
		else if (font->shadow == 5)
			blf_texture5_draw(gt->uv, dx, y1, dx1, y2);
		else
			blf_texture_draw(gt->uv, dx, y1, dx1, y2);

		glColor4fv(color);
		x= xo;
		y= yo;

		dx= floor(x + gt->pos_x);
		dx1= dx + gt->width;
		y1= y + gt->pos_y;
		y2= y + gt->pos_y - gt->height;
	}

	if (font->blur==3)
		blf_texture3_draw(gt->uv, dx, y1, dx1, y2);
	else if (font->blur==5)
		blf_texture5_draw(gt->uv, dx, y1, dx1, y2);
	else
		blf_texture_draw(gt->uv, dx, y1, dx1, y2);
	
	return(1);
}

int blf_glyph_bitmap_render(FontBLF *font, GlyphBLF *g, float x, float y)
{
	GlyphBitmapBLF *gt;
	GLubyte null_bitmap= 0;

	gt= g->bitmap_data;
	if (!gt->image)
		return(1);

	if (font->flags & BLF_CLIPPING) {
		if (!BLI_in_rctf(&font->clip_rec, x + font->pos[0], y + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, x + font->pos[0], y + gt->height + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, x + gt->width + font->pos[0], y + gt->height + font->pos[1]))
			return(0);
		if (!BLI_in_rctf(&font->clip_rec, x + gt->width + font->pos[0], y + font->pos[1]))
			return(0);
	}

	glBitmap(0, 0, 0.0, 0.0, x + font->pos[0], y - font->pos[1], (const GLubyte *)&null_bitmap);
	glPixelStorei(GL_UNPACK_ROW_LENGTH, gt->pitch * 8);
	glBitmap(gt->width, gt->height, 0.0, gt->pos_y, 0.0, 0.0, (const GLubyte *)gt->image);
	glBitmap(0, 0, 0.0, 0.0, -x - font->pos[0], -y + font->pos[1], (const GLubyte *)&null_bitmap);
	return(1);
}

int blf_glyph_render(FontBLF *font, GlyphBLF *g, float x, float y)
{
	if (font->mode == BLF_MODE_BITMAP)
		return(blf_glyph_bitmap_render(font, g, x, y));
	return(blf_glyph_texture_render(font, g, x, y));
}