From b17ac2ecee76552feed27813f08d1e7087f26c6c Mon Sep 17 00:00:00 2001 From: Andy Spencer Date: Mon, 30 Jan 2012 07:50:27 +0000 Subject: [PATCH] Improve rendering of non lat-lon tiles There have been a long standing bugs related to this.. Up until now the solution was to only use tiles that split along lat-long lines and to also split the geometry (in roam) along the same lines. Hopefully this allows tiles to be rendered properly. See examples/tex.c for details of how this rendering works. --- src/objects/grits-tile.c | 137 ++++++++++++++++++++++++--------------- 1 file changed, 86 insertions(+), 51 deletions(-) diff --git a/src/objects/grits-tile.c b/src/objects/grits-tile.c index 68e71cc..cba5b75 100644 --- a/src/objects/grits-tile.c +++ b/src/objects/grits-tile.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2009-2010 Andy Spencer + * Copyright (C) 2009-2010, 2012 Andy Spencer * * 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 @@ -37,6 +37,8 @@ #include "gtkgl.h" #include "grits-tile.h" +guint grits_tile_mask = 0; + gchar *grits_tile_path_table[2][2] = { {"00.", "01."}, {"10.", "11."}, @@ -120,17 +122,17 @@ static gboolean _grits_tile_precise(GritsPoint *eye, GritsBounds *bounds, gdouble lon_dist = bounds->e - bounds->w; gdouble tile_res = ll2m(lon_dist, lat_point)/width; - /* This isn't really right, but it helps with memory since we don't (yet?) test if the tile - * would be drawn */ + /* This isn't really right, but it helps with memory since we don't + * (yet?) test if the tile would be drawn */ gdouble scale = eye->elev / min_dist; view_res /= scale; //view_res /= 1.4; /* make it a little nicer, not sure why this is needed */ //g_message("tile=(%7.2f %7.2f %7.2f %7.2f) " // "eye=(%9.1f %9.1f %9.1f) " // "elev=%9.1f / dist=%9.1f = %f", - // tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w, - // lat, lon, elev, - // elev, min_dist, scale); + // bounds->n, bounds->s, bounds->e, bounds->w, + // eye->lat, eye->lon, eye->elev, + // eye->elev, min_dist, scale); return tile_res < max_res || tile_res < view_res; @@ -195,19 +197,25 @@ void grits_tile_update(GritsTile *tile, GritsPoint *eye, { //g_debug("GritsTile: update - %p->atime = %u", // tile, (guint)tile->atime); + GritsTile *child; if (tile == NULL) return; - GRITS_OBJECT(tile)->hidden = TRUE; - if (_grits_tile_precise(eye, &tile->edge, res, width, height)) - return; - tile->atime = time(NULL); - GRITS_OBJECT(tile)->hidden = FALSE; - if (!tile->data) load_func(tile, user_data); + tile->atime = time(NULL); + + /* Is this tile high enough resolution? */ + if (_grits_tile_precise(eye, &tile->edge, res, width, height)) { + grits_tile_foreach(tile, child) + if (child) + GRITS_OBJECT(child)->hidden = TRUE; + return; + } + + /* Need more resolution, split tile and update recursively */ if (!tile->children[0][0]) { switch (tile->proj) { case GRITS_PROJ_LATLON: _grits_tile_split_latlon(tile); break; @@ -215,10 +223,11 @@ void grits_tile_update(GritsTile *tile, GritsPoint *eye, } } - GritsTile *child; - grits_tile_foreach(tile, child) + grits_tile_foreach(tile, child) { + GRITS_OBJECT(child)->hidden = FALSE; grits_tile_update(child, eye, res, width, height, load_func, user_data); + } } @@ -319,6 +328,25 @@ void grits_tile_free(GritsTile *root, GritsTileFreeFunc free_func, gpointer user g_object_unref(root); } +/* Load texture mask so we can draw a texture to just a part of a triangle */ +static guint _grits_tile_load_mask(void) +{ + guint tex; + guint8 byte = 0xff; + glGenTextures(1, &tex); + glBindTexture(GL_TEXTURE_2D, tex); + + glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 1, 1, 0, + GL_ALPHA, GL_UNSIGNED_BYTE, &byte); + + glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); + glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER); + return tex; +} + /* Draw a single tile */ static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *triangles) { @@ -327,6 +355,9 @@ static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *tri if (!triangles) g_warning("GritsOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f", tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w); + if (!grits_tile_mask) + grits_tile_mask = _grits_tile_load_mask(); + //g_message("drawing %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f", // g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w); tile->atime = time(NULL); @@ -384,65 +415,69 @@ static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *tri xy[i][1] = tile->coords.n + xy[i][1]*yscale; } - glEnable(GL_TEXTURE_2D); + /* Polygon offset */ glEnable(GL_POLYGON_OFFSET_FILL); - glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data); glPolygonOffset(0, -tile->zindex); + + /* Setup texture */ + glActiveTexture(GL_TEXTURE0); + glEnable(GL_TEXTURE_2D); + glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data); + glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); + + /* Enable texture mask */ + if (tile->proj == GRITS_PROJ_MERCATOR) { + glActiveTexture(GL_TEXTURE1); + glEnable(GL_TEXTURE_2D); + glBindTexture(GL_TEXTURE_2D, grits_tile_mask); + glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); + } + + /* Draw triangle */ glBegin(GL_TRIANGLES); - glNormal3dv(tri->p.r->norm); glTexCoord2dv(xy[0]); glVertex3dv((double*)tri->p.r); - glNormal3dv(tri->p.m->norm); glTexCoord2dv(xy[1]); glVertex3dv((double*)tri->p.m); - glNormal3dv(tri->p.l->norm); glTexCoord2dv(xy[2]); glVertex3dv((double*)tri->p.l); + glNormal3dv(tri->p.r->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[0]); glMultiTexCoord2dv(GL_TEXTURE1, xy[0]); glVertex3dv((double*)tri->p.r); + glNormal3dv(tri->p.m->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[1]); glMultiTexCoord2dv(GL_TEXTURE1, xy[1]); glVertex3dv((double*)tri->p.m); + glNormal3dv(tri->p.l->norm); glMultiTexCoord2dv(GL_TEXTURE0, xy[2]); glMultiTexCoord2dv(GL_TEXTURE1, xy[2]); glVertex3dv((double*)tri->p.l); glEnd(); + + /* Disable texture mask */ + glDisable(GL_TEXTURE_2D); + glActiveTexture(GL_TEXTURE0); } } /* Draw the tile */ static void grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl) { + if (!tile || !tile->data || GRITS_OBJECT(tile)->hidden) + return; + /* Only draw children if possible */ - gboolean has_children = FALSE; + gboolean has_all_children = TRUE; GritsTile *child; grits_tile_foreach(tile, child) - if (child && child->data) - has_children = TRUE; + if (!child || !child->data || GRITS_OBJECT(child)->hidden) + has_all_children = FALSE; - GList *triangles = NULL; - if (has_children && !GRITS_OBJECT(tile)->hidden) { - /* TODO: simplify this */ - const gdouble rows = G_N_ELEMENTS(tile->children); - const gdouble cols = G_N_ELEMENTS(tile->children[0]); - const gdouble lat_dist = tile->edge.n - tile->edge.s; - const gdouble lon_dist = tile->edge.e - tile->edge.w; - const gdouble lat_step = lat_dist / rows; - const gdouble lon_step = lon_dist / cols; - int row, col; - grits_tile_foreach_index(tile, row, col) { - GritsTile *child = tile->children[row][col]; - if (child && child->data) { - grits_tile_draw_rec(child, opengl); - } else { - const gdouble n = tile->edge.n-(lat_step*(row+0)); - const gdouble s = tile->edge.n-(lat_step*(row+1)); - const gdouble e = tile->edge.w+(lon_step*(col+1)); - const gdouble w = tile->edge.w+(lon_step*(col+0)); - GList *these = roam_sphere_get_intersect(opengl->sphere, - FALSE, n, s, e, w); - triangles = g_list_concat(triangles, these); - } - } - } else { - triangles = roam_sphere_get_intersect(opengl->sphere, FALSE, + /* Draw parent tile underneath */ + if (!has_all_children) { + GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE, tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w); - } - if (triangles) grits_tile_draw_one(tile, opengl, triangles); - g_list_free(triangles); + g_list_free(triangles); + } + + /* Draw child tiles */ + grits_tile_foreach(tile, child) + grits_tile_draw_rec(child, opengl); } static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl) { glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LESS); + glEnable(GL_ALPHA_TEST); + glAlphaFunc(GL_GREATER, 0.5); grits_tile_draw_rec(GRITS_TILE(tile), opengl); } -- 2.43.2