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

#include <assert.h>
#include <cx/printf.h>

#include <GL/glew.h>

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

    // 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("Rendering TTF surface failed: %s", SDL_GetError());
        return;
    }
    if (asc_test_flag(text->base.data.flags, ASC_TEXT_CENTERED_FLAG)) {
        unsigned short newoffx = surface->w / 2;
        node->position.x = node->position.x + (float)(text->offx - newoffx);
        text->offx = newoffx;
    }

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

    // If dimensions changed, update the mesh
    if (text->dimension.x != (unsigned)surface->w || text->dimension.y != (unsigned)surface->h) {
        text->dimension.x = surface->w;
        text->dimension.y = surface->h;
        const asc_vec2f uv_scale = asc_texture_calculate_uv_scale(sprite->texture, text->dimension, asc_vec2f_one);
        asc_mesh_plane_2d(&text->base.mesh,
            .size = asc_vec2f_new(surface->w, surface->h),
            .uv_scale = uv_scale
        );
    }

    // Free the surface
    SDL_FreeSurface(surface);

    // Schedule for transform update
    asc_node_update_transform(node);
}

static void asc_text_destroy(AscSceneNode *node) {
    AscText *text = (AscText*) node;
    AscSprite *sprite = (AscSprite*) node;
    asc_mesh_destroy(&sprite->mesh);
    asc_texture_destroy(sprite->texture, 1);
    assert(sprite->texture->refcount == 0);
    cxFreeDefault(sprite->texture);
    cx_strfree(&text->text);
}

AscSceneNode *asc_text_create(struct asc_text_create_args args) {
    AscText *text = cxZallocDefault(sizeof(AscText));
    AscSceneNode *node = &text->base.data;

    // node properties
    asc_scene_node_name(node, args.name);
    node->render_group = ASC_RENDER_GROUP_SPRITE_BLEND_RECT;
    node->destroy_func = asc_text_destroy;
    node->update_func = asc_text_update;
    node->position = asc_vec3f_new(args.x, args.y, ASC_SCENE_2D_DEPTH_OFFSET);
    node->scale = asc_vec3f_one;

    // text properties
    node->flags = args.alignment; // use flags variable to save some space
    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 texture
    // mesh will be created in the update func
    text->base.texture = cxMallocDefault(sizeof(AscTexture));
    asc_texture_init_rectangle(text->base.texture, 1);
    asc_text_update(node);

    return node;
}

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