glcompimage.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
#include <glcomp/glcompimage.h>
#include <glcomp/glcompfont.h>
#include <glcomp/glcompset.h>
#include <glcomp/glutils.h>
#include <glcomp/glcomptexture.h>
#include <stdbool.h>
#include <stddef.h>
#include <util/alloc.h>
 
glCompImage *glCompImageNew(void *par, float x, float y) {
    glCompImage *p = gv_alloc(sizeof(glCompImage));
    glCompInitCommon(&p->base, par, x, y);
    p->texture = NULL;
    p->base.common.functions.draw = glCompImageDraw;
    return p;
}
 
/* glCompImageNewFile:
 * Creates image from given input file.
 * At present, we assume png input.
 * Return 0 on failure.
 */
glCompImage *glCompImageNewFile(float x, float y, const char *imgfile) {
    int imageWidth, imageHeight;
    cairo_surface_t *surface = NULL;
    const unsigned char *data = glCompLoadPng(&surface, imgfile, &imageWidth,
                                              &imageHeight);
    glCompImage *p;
 
    if (!data) return NULL;
    p = glCompImageNew(NULL, x, y);
    if (!glCompImageLoad(p, data, imageWidth, imageHeight, 0)) {
        glCompImageDelete (p);
        p = NULL;
    }
    cairo_surface_destroy(surface);
    return p;
}
 
void glCompImageDelete(glCompImage * p)
{
    glCompEmptyCommon(&p->base.common);
    if (p->texture)
        glCompDeleteTexture(p->texture);
    free(p);
}
 
int glCompImageLoad(glCompImage *i, const unsigned char *data, int width,
                    int height, bool is2D) {
    if (data != NULL) {         /*valid image data */
        glCompDeleteTexture(i->texture);
        i->texture =
            glCompSetAddNewTexImage(i->base.common.compset, width, height, data,
                                    is2D);
        if (i->texture) {
            i->base.common.width = width;
            i->base.common.height = height;
            return 1;
        }
 
    }
    return 0;
}
 
int glCompImageLoadPng(glCompImage *i, const char *pngFile) {
    int imageWidth, imageHeight;
    cairo_surface_t *surface = NULL;
    const unsigned char *data = glCompLoadPng(&surface, pngFile, &imageWidth,
                                              &imageHeight);
    if (data == NULL) {
        return 0;
    }
    const int rc = glCompImageLoad(i, data, imageWidth, imageHeight, 1);
    cairo_surface_destroy(surface);
    return rc;
}
 
void glCompImageDraw(void *obj)
{
    glCompImage *p = obj;
    glCompCommon ref = p->base.common;
    float w,h,d;
 
    glCompCalcWidget(p->base.common.parent, &p->base.common, &ref);
    if (!p->base.common.visible)
        return;
    if (!p->texture)
        return;
 
    if(p->texture->id <=0)
    {
        glRasterPos2f(ref.pos.x, ref.pos.y);
        glDrawPixels(p->texture->width, p->texture->height, GL_RGBA,GL_UNSIGNED_BYTE, p->texture->data);
    }
    else
    {
        w = p->width;
        h = p->height;
        d = (float)p->base.common.layer * GLCOMPSET_BEVEL_DIFF;
        glDisable(GL_BLEND);
        glEnable(GL_TEXTURE_2D);
        glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
        glBindTexture(GL_TEXTURE_2D,p->texture->id);
        glBegin(GL_QUADS);
                glTexCoord2d(0.0f, 1.0f);glVertex3d(ref.pos.x,ref.pos.y,d);
                glTexCoord2d(1.0f, 1.0f);glVertex3d(ref.pos.x+w,ref.pos.y,d);
                glTexCoord2d(1.0f, 0.0f);glVertex3d(ref.pos.x+w,ref.pos.y+h,d);
                glTexCoord2d(0.0f, 0.0f);glVertex3d(ref.pos.x,ref.pos.y+h,d);
        glEnd();
 
 
        glDisable(GL_TEXTURE_2D);
        glEnable(GL_BLEND);
    }
 
}