nviz/draw.c

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/*!
   \file lib/nviz/draw.c
 
   \brief Nviz library -- Draw map objects to GLX context
 
   Based on visualization/nviz/src/draw.c and
   visualization/nviz/src/togl_flythrough.c
 
   SPDX-FileCopyrightText: 2008, 2010-2011 GRASS Development Team
   SPDX-License-Identifier: GPL-2.0-or-later
 
   \author Updated/modified by Martin Landa <landa.martin gmail.com> (Google SoC
           2008/2010) \author Textures by Anna Kratochvilova
 */
 
#include <grass/nviz.h>
 
#ifndef GL_CLAMP_TO_EDGE
#define GL_CLAMP_TO_EDGE 0x812F
#endif
 
static int sort_surfs_max(int *, int *, int *, int);
 
/*!
   \brief Draw all loaded surfaces
 
   \param dc nviz data
 
   \return 1
 */
int Nviz_draw_all_surf(nv_data *dc)
{
    int i, nsurfs;
    int sortSurfs[MAX_SURFS], sorti[MAX_SURFS];
    int *surf_list;
    float x, y, z;
    int num, w;
 
    /* Get position for Light 1 */
    num = 1;
    x = dc->light[num].x;
    y = dc->light[num].y;
    z = dc->light[num].z;
    w = dc->light[num].z;
 
    surf_list = GS_get_surf_list(&nsurfs);
 
    sort_surfs_max(surf_list, sortSurfs, sorti, nsurfs);
 
    G_free(surf_list);
 
    /* re-initialize lights */
    GS_setlight_position(num, x, y, z, w);
    num = 2;
    GS_setlight_position(num, 0., 0., 1., 0);
 
    for (i = 0; i < nsurfs; i++) {
        GS_draw_surf(sortSurfs[i]);
    }
 
    /* GS_draw_cplane_fence params will change - surfs aren't used anymore */
    for (i = 0; i < MAX_CPLANES; i++) {
        if (dc->cp_on[i])
            GS_draw_cplane_fence(sortSurfs[0], sortSurfs[1], i);
    }
 
    return 1;
}
 
/*!
   \brief Sorts surfaces by max elevation, lowest to highest.
 
   Puts ordered id numbers in id_sort, leaving id_orig unchanged.
   Puts ordered indices of surfaces from id_orig in indices.
 
   \param surf pointer to surface array
   \param id_sort
   \param indices
   \param num
 
   \return 1
 */
int sort_surfs_max(int *surf, int *id_sort, int *indices, int num)
{
    int i, j;
    float maxvals[MAX_SURFS];
    float tmp, max = 0., tmin, tmax, tmid;
 
    for (i = 0; i < num; i++) {
        GS_get_zextents(surf[i], &tmin, &tmax, &tmid);
        if (i == 0)
            max = tmax;
        else
            max = max < tmax ? tmax : max;
        maxvals[i] = tmax;
    }
 
    for (i = 0; i < num; i++) {
        tmp = maxvals[0];
        indices[i] = 0;
        for (j = 0; j < num; j++) {
            if (maxvals[j] < tmp) {
                tmp = maxvals[j];
                indices[i] = j;
            }
        }
 
        maxvals[indices[i]] = max + 1;
        id_sort[i] = surf[indices[i]];
    }
 
    return 1;
}
 
/*!
   \brief Draw all loaded vector sets (lines)
 
   \return 1
 */
int Nviz_draw_all_vect(void)
{
    /* GS_set_cancel(0); */
 
    /* in case transparency is set */
    GS_set_draw(GSD_BOTH);
 
    GS_ready_draw();
 
    GV_alldraw_vect();
 
    GS_done_draw();
 
    GS_set_draw(GSD_BACK);
 
    /* GS_set_cancel(0); */
 
    return 1;
}
 
/*!
   \brief Draw all loaded vector point sets
 
   \return 1
 */
int Nviz_draw_all_site(void)
{
    int i;
    int *site_list, nsites;
 
    site_list = GP_get_site_list(&nsites);
 
    /* in case transparency is set */
    GS_set_draw(GSD_BOTH);
 
    GS_ready_draw();
 
    for (i = 0; i < nsites; i++) {
        GP_draw_site(site_list[i]);
    }
    G_free(site_list);
 
    GS_done_draw();
 
    GS_set_draw(GSD_BACK);
 
    return 1;
}
 
/*!
   \brief Draw all loaded volume sets
 
   \return 1
 */
int Nviz_draw_all_vol(void)
{
    int *vol_list, nvols, i;
 
    vol_list = GVL_get_vol_list(&nvols);
 
    /* in case transparency is set */
    GS_set_draw(GSD_BOTH);
 
    GS_ready_draw();
 
    for (i = 0; i < nvols; i++) {
        GVL_draw_vol(vol_list[i]);
    }
 
    G_free(vol_list);
 
    GS_done_draw();
 
    GS_set_draw(GSD_BACK);
 
    return 1;
}
 
/*!
   \brief Draw all map objects (in full resolution) and decorations
 
   \param data nviz data
 */
int Nviz_draw_all(nv_data *data)
{
    int i;
    int draw_surf, draw_vect, draw_site, draw_vol;
 
    draw_surf = 1;
    draw_vect = 1;
    draw_site = 1;
    draw_vol = 1;
    /*
       draw_north_arrow = 0;
       arrow_x = 0;
       draw_label = 0;
       draw_legend = 0;
       draw_fringe = 0;
       draw_scalebar = 0;
       draw_bar_x = 0;
     */
 
    GS_set_draw(GSD_BACK); /* needs to be BACK to avoid flickering */
 
    GS_ready_draw();
 
    GS_clear(data->bgcolor);
 
    if (draw_surf)
        Nviz_draw_all_surf(data);
 
    if (draw_vect)
        Nviz_draw_all_vect();
 
    if (draw_site)
        Nviz_draw_all_site();
 
    if (draw_vol)
        Nviz_draw_all_vol();
 
    for (i = 0; i < data->num_fringes; i++) {
        struct fringe_data *f = data->fringe[i];
 
        GS_draw_fringe(f->id, f->color, f->elev, f->where);
    }
 
    /* North Arrow */
    if (data->draw_arrow) {
        gsd_north_arrow(data->arrow->where, data->arrow->size, 0,
                        data->arrow->color, data->arrow->color);
    }
 
    /* scale bar */
    for (i = 0; i < data->num_scalebars; i++) {
        if (data->scalebar[i]) {
            struct scalebar_data *s = data->scalebar[i];
 
            gsd_scalebar_v2(s->where, s->size, 0, s->color, s->color);
        }
    }
    GS_done_draw();
    GS_set_draw(GSD_BACK);
 
    return 1;
}
 
/*!
   \brief Draw all surfaces in wireframe (quick mode)
 
   Draw modes:
   - DRAW_QUICK_SURFACE
   - DRAW_QUICK_VLINES
   - DRAW_QUICK_VPOINTS
   - DRAW_QUICK_VOLUME
 
   \param data nviz data
   \param draw_mode draw mode
 
   \return 1
 */
int Nviz_draw_quick(nv_data *data, int draw_mode)
{
    GS_set_draw(GSD_BACK);
 
    GS_ready_draw();
 
    GS_clear(data->bgcolor);
 
    /* draw surfaces */
    if (draw_mode & DRAW_QUICK_SURFACE)
        GS_alldraw_wire();
 
    /* draw vector lines */
    if (draw_mode & DRAW_QUICK_VLINES)
        GV_alldraw_vect();
 
    /* draw vector points */
    if (draw_mode & DRAW_QUICK_VPOINTS)
        GP_alldraw_site();
 
    /* draw volumes */
    if (draw_mode & DRAW_QUICK_VOLUME) {
        GVL_alldraw_wire();
    }
 
    GS_done_draw();
 
    return 1;
}
 
/*!
   \brief Load image into texture
 
   \param image_data image data
   \param width, height image screen size
   \param alpha has alpha channel
 */
int Nviz_load_image(GLubyte *image_data, int width, int height, int alpha)
{
    unsigned int texture_id;
    int in_format;
    GLenum format;
 
    if (alpha) {
        in_format = 4;
        format = GL_RGBA;
    }
    else {
        in_format = 3;
        format = GL_RGB;
    }
    glGenTextures(1, &texture_id);
    glBindTexture(GL_TEXTURE_2D, texture_id);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
    glTexImage2D(GL_TEXTURE_2D, 0, in_format, width, height, 0, format,
                 GL_UNSIGNED_BYTE, image_data);
 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 
    return texture_id;
}
 
/*!
   \brief Set ortho view for drawing images
 
   \param width, height image screen size
 */
void Nviz_set_2D(int width, int height)
{
    glEnable(GL_BLEND); /* images are transparent */
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, width, 0, height, -1, 1);
 
    /* set coordinate system from upper left corner */
    glScalef(1, -1, 1);
    glTranslatef(0, -height, 0);
 
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}
 
/*!
   \brief Draw image as texture
 
   \param x, y image coordinates
   \param width, height image size
   \param texture_id texture id
 */
void Nviz_draw_image(int x, int y, int width, int height, int texture_id)
{
    glBindTexture(GL_TEXTURE_2D, texture_id);
    GS_set_draw(GSD_FRONT);
 
    glEnable(GL_TEXTURE_2D);
 
    glBegin(GL_QUADS);
 
    glTexCoord2d(0.0, 1.0);
    glVertex2d(x, y);
    glTexCoord2d(0.0, 0.0);
    glVertex2d(x, y + height);
    glTexCoord2d(1.0, 0.0);
    glVertex2d(x + width, y + height);
    glTexCoord2d(1.0, 1.0);
    glVertex2d(x + width, y);
 
    glEnd();
 
    GS_done_draw();
    glDisable(GL_TEXTURE_2D);
}
 
/*!
   \brief Delete texture
 
   \param texture_id texture id
 */
void Nviz_del_texture(int texture_id)
{
    GLuint t[1];
 
    t[0] = texture_id;
    glDeleteTextures(1, t);
}
 
/*!
   \brief Get maximum texture size
 
 */
void Nviz_get_max_texture(int *size)
{
    glGetIntegerv(GL_MAX_TEXTURE_SIZE, size);
}