src/text.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * Copyright 2023 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "ascension/ui/text.h"
#include "ascension/context.h"
#include "ascension/error.h"
#include "ascension/shader.h"

#include <cx/printf.h>

#include <GL/glew.h>

static void asc_text_update(AscSceneNode *node) {
    AscSprite *sprite = (AscSprite*) node;
    AscText *text = (AscText*) node;

    // Generate new texture, if required
    if (asc_texture_uninitialized(&sprite->tex)) {
        asc_texture_init_rectangle(&sprite->tex);
    }

    // Render text onto a surface
    TTF_Font *font = asc_font_load(text->font);
    static int alignments[] = {
            TTF_WRAPPED_ALIGN_LEFT,
            TTF_WRAPPED_ALIGN_CENTER,
            TTF_WRAPPED_ALIGN_RIGHT
    };
    TTF_SetFontWrappedAlign(
            font, alignments[text->base.data.flags & ASC_TEXT_ALIGNMENT_MASK]);
    SDL_Surface *surface = TTF_RenderUTF8_Blended_Wrapped(
            font, text->text.ptr, asc_col_sdl(text->color), text->max_width
    );
    if (surface == NULL) {
        asc_error(SDL_GetError());
        return;
    }
    asc_set_scale2d(node, surface->w, surface->h);
    if (asc_test_flag(text->base.data.flags, ASC_TEXT_CENTERED_FLAG)) {
        unsigned short newoffx = surface->w / 2;
        asc_vec2i pos = asc_get_position2d(node);
        asc_set_position2d(node, pos.x + text->offx - newoffx, pos.y);
        text->offx = newoffx;
    }

    // Transfer Image Data
    asc_texture_from_surface(&sprite->tex, surface);

    // Free the surface
    SDL_FreeSurface(surface);
}

static void asc_text_free(AscSceneNode *node) {
    AscText *text = (AscText*) node;
    AscSprite *sprite = (AscSprite*) node;
    asc_texture_destroy(&sprite->tex);
    cx_strfree(&text->text);
    free(node);
}

AscSceneNode *asc_text_create(struct asc_text_create_args args) {
    AscText *text = calloc(1, sizeof(AscText));
    AscSceneNode *node = (AscSceneNode*) text;

    node->render_group = ASC_RENDER_GROUP_SPRITE_BLEND;
    node->free_func = asc_text_free;
    node->update_func = asc_text_update;

    node->flags = args.alignment;
    node->position.x = (float) args.x;
    node->position.y = (float) args.y;
    text->max_width = args.max_width;
    text->font = asc_active_font;
    text->color = asc_context.ink;
    if (args.text == NULL) {
        text->text = cx_mutstr(strdup(" "));
    } else {
        text->text = cx_mutstr(strdup(args.text));
    }

    // initialize
    asc_text_update(node);

    return node;
}

void asc_text_printf(
        AscSceneNode *node,
        char const* format,
        ...
) {
    cxmutstr text = ((AscText*)node)->text;
    va_list ap;
    va_start(ap, format);
    cx_vsprintf(&text.ptr, &text.length, format, ap);
    va_end(ap);
    asc_node_update(node);
}