blf_glyph.c

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/*
 * ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 FT_BITMAP_H

#include "MEM_guardedalloc.h"

#include "DNA_vec_types.h"
#include "DNA_userdef_types.h"

#include "BLI_blenlib.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;

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

    memset(gc->glyph_ascii_table, 0, sizeof(gc->glyph_ascii_table));
    memset(gc->bucket, 0, sizeof(gc->bucket));

    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_clear(FontBLF *font)
{
    GlyphCacheBLF *gc;
    GlyphBLF *g;
    int i;

    for(gc=font->cache.first; gc; gc=gc->next) {
        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);
            }
        }

        memset(gc->glyph_ascii_table, 0, sizeof(gc->glyph_ascii_table));
    }
}

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);
        }
    }

    if (gc->cur_tex+1 > 0)
        glDeleteTextures(gc->cur_tex+1, gc->textures);
    free((void *)gc->textures);
    MEM_freeN(gc);
}

static 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, (font->tex_bind_state= 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_add(FontBLF *font, unsigned int index, unsigned int c)
{
    FT_GlyphSlot slot;
    GlyphBLF *g;
    FT_Error err;
    FT_Bitmap bitmap, tempbitmap;
    int sharp = (U.text_render & USER_TEXT_DISABLE_AA);
    FT_BBox bbox;
    unsigned int key;

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

    if (sharp)
        err = FT_Load_Glyph(font->face, (FT_UInt)index, FT_LOAD_TARGET_MONO);
    else
        err = FT_Load_Glyph(font->face, (FT_UInt)index, FT_LOAD_TARGET_NORMAL | FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP); /* Sure about NO_* flags? */
    if (err)
        return NULL;

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

    if (sharp) {
        err = FT_Render_Glyph(slot, FT_RENDER_MODE_MONO);

        /* Convert result from 1 bit per pixel to 8 bit per pixel */
        /* Accum errors for later, fine if not interested beyond "ok vs any error" */
        FT_Bitmap_New(&tempbitmap);
        err += FT_Bitmap_Convert(font->ft_lib, &slot->bitmap, &tempbitmap, 1); /* Does Blender use Pitch 1 always? It works so far */
        err += FT_Bitmap_Copy(font->ft_lib, &tempbitmap, &slot->bitmap);
        err += FT_Bitmap_Done(font->ft_lib, &tempbitmap);
    } else {
        err = FT_Render_Glyph(slot, FT_RENDER_MODE_NORMAL);
    }

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

    g= (GlyphBLF *)MEM_callocN(sizeof(GlyphBLF), "blf_glyph_add");
    g->c= c;
    g->idx= (FT_UInt)index;
    g->xoff= -1;
    g->yoff= -1;
    bitmap= slot->bitmap;
    g->width= bitmap.width;
    g->height= bitmap.rows;

    if (g->width && g->height) {
        if (sharp) {
            /* Font buffer uses only 0 or 1 values, Blender expects full 0..255 range */
            int i;
            for (i=0; i < (g->width * g->height); i++) {
                bitmap.buffer[i] = 255 * bitmap.buffer[i];
            }
        }

        g->bitmap= (unsigned char *)MEM_mallocN(g->width * g->height, "glyph bitmap");
        memcpy((void *)g->bitmap, (void *)bitmap.buffer, g->width * g->height);
    }

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

    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;

    key= blf_hash(g->c);
    BLI_addhead(&(font->glyph_cache->bucket[key]), g);
    return g;
}

void blf_glyph_free(GlyphBLF *g)
{
    /* don't need free the texture, the GlyphCache already
     * have a list of all the texture and free it.
     */
    if (g->bitmap)
        MEM_freeN(g->bitmap);
    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(const float shadow_col[4], 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;

    color[0]= shadow_col[0];
    color[1]= shadow_col[1];
    color[2]= shadow_col[2];
    
    for(dx=-2; dx<3; dx++) {
        for(dy=-2; dy<3; dy++, fp++) {
            color[3]= *(fp) * shadow_col[3];
            glColor4fv(color);
            blf_texture_draw(uv, x1+dx, y1+dy, x2+dx, y2+dy);
        }
    }
    
    glColor4fv(color);
}

static void blf_texture3_draw(const float shadow_col[4], 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;

    color[0]= shadow_col[0];
    color[1]= shadow_col[1];
    color[2]= shadow_col[2];

    for(dx=-1; dx<2; dx++) {
        for(dy=-1; dy<2; dy++, fp++) {
            color[3]= *(fp) * shadow_col[3];
            glColor4fv(color);
            blf_texture_draw(uv, x1+dx, y1+dy, x2+dx, y2+dy);
        }
    }
    
    glColor4fv(color);
}

int blf_glyph_render(FontBLF *font, GlyphBLF *g, float x, float y)
{
    float dx, dx1;
    float y1, y2;
    float xo, yo;

    if ((!g->width) || (!g->height))
        return 1;

    if (g->build_tex == 0) {
        GlyphCacheBLF *gc= font->glyph_cache;

        if (font->max_tex_size == -1)
            glGetIntegerv(GL_MAX_TEXTURE_SIZE, (GLint *)&font->max_tex_size);

        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);
            }
        }

        g->tex= gc->textures[gc->cur_tex];
        g->xoff= gc->x_offs;
        g->yoff= gc->y_offs;

        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, g->tex);
        glTexSubImage2D(GL_TEXTURE_2D, 0, g->xoff, g->yoff, g->width, g->height, GL_ALPHA, GL_UNSIGNED_BYTE, g->bitmap);
        glPopClientAttrib();

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

        gc->rem_glyphs--;
        g->build_tex= 1;
    }

    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 + g->pos_x);
    dx1= dx + g->width;
    y1= y + g->pos_y;
    y2= y + g->pos_y - g->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;
    }

    if (font->tex_bind_state != g->tex) {
        glBindTexture(GL_TEXTURE_2D, (font->tex_bind_state= g->tex));
    }

    if (font->flags & BLF_SHADOW) {

        switch(font->shadow) {
            case 3:
                blf_texture3_draw(font->shadow_col, g->uv, dx, y1, dx1, y2);
                break;
            case 5:
                blf_texture5_draw(font->shadow_col, g->uv, dx, y1, dx1, y2);
                break;
            default:
                glColor4fv(font->shadow_col);
                blf_texture_draw(g->uv, dx, y1, dx1, y2);
                break;
        }

        glColor4fv(font->orig_col);

        x= xo;
        y= yo;

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

    switch(font->blur) {
        case 3:
            blf_texture3_draw(font->orig_col, g->uv, dx, y1, dx1, y2);
            break;
        case 5:
            blf_texture5_draw(font->orig_col, g->uv, dx, y1, dx1, y2);
            break;
        default:
            blf_texture_draw(g->uv, dx, y1, dx1, y2);
            break;
    }

    return 1;
}