Add BiomeOverlay rendermode.

A "biomes" option is specified in rendermodes.py but not yet wired up!
May do unexpected things if used :-)

overviewer_core/rendermodes.py

@@ -208,6 +208,12 @@ class MineralOverlay(Overlay):
         'minerals' : ('a list of (blockid, (r, g, b)) tuples for coloring minerals', None),
     }
 
+class BiomeOverlay(Overlay):
+    name = "overlay-biomes"
+    options = {
+        'biomes' : ('a list of (biome, (r, g, b)) tuples for coloring biomes', None),
+    }
+
 class Hide(RenderPrimitive):
     name = "hide"
     options = {

overviewer_core/src/primitives/overlay-biomes.c

@@ -0,0 +1,172 @@
+/*
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "overlay.h"
+#include "biomes.h"
+
+typedef struct {
+    /* inherits from overlay */
+    RenderPrimitiveOverlay parent;
+    
+    void *biomes;
+} RenderPrimitiveBiomes;
+
+struct BiomeColor {
+    unsigned char biome;
+    unsigned char r, g, b;
+};
+
+static struct BiomeColor default_biomes[] = {
+    /* 0 */
+    {0, 135, 206, 250}, /* Ocean */
+    {1, 198, 238, 140}, /* Plains */
+    {2, 227, 207, 87}, /* Desert */
+    {3, 155, 155, 155}, /* Extreme Hills */
+    {4, 184, 239, 134}, /* Forest */
+    /* 5 */
+    {5, 148, 228, 220}, /* Taiga */
+    {6, 0, 100, 90}, /* Swampland */
+    {7, 70, 130, 180}, /* River */
+    {8, 176, 23, 31}, /* Hell */
+    {9, 255, 255, 255}, /* Sky */
+    /* 10 */
+    {10, 155, 55, 255}, /* FrozenOcean */
+    {11, 255, 55, 255}, /* FrozenRiver */
+    {12, 155, 255, 255}, /* Ice Plains */
+    {13, 205, 205, 255}, /* Ice Mountains */
+    {14, 55, 55, 55}, /* MushroomIsland */
+    /* 15 */
+    {15, 75, 75, 75}, /* MushroomIslandShore */
+    {16, 255, 215, 80}, /* Beach */
+    {17, 140, 155, 255}, /* DesertHills */
+    {18, 105, 255, 155}, /* ForestHills */
+    {19, 75, 125, 75}, /* TaigaHills */
+    /* 20 */
+    {20, 255, 25, 15}, /* Extreme Hills Edge */
+    {21, 0, 255, 55}, /* Jungle */
+    {22, 75, 255, 255}, /* Jungle Mountains */
+    /* end of list marker */
+    {255, 0, 0, 0}
+};
+
+static void get_color(void *data, RenderState *state,
+                      unsigned char *r, unsigned char *g, unsigned char *b, unsigned char *a) {
+    
+    unsigned char biome;
+    int x = state->x, z = state->z, y_max, y;
+    int max_i = -1;
+    RenderPrimitiveBiomes* self = (RenderPrimitiveBiomes *)data;
+    struct BiomeColor *biomes = (struct BiomeColor *)(self->biomes);
+    *a = 0;
+    
+    y_max = state->y + 1;
+    for (y = state->chunky * -16; y <= y_max; y++) {
+        int i, tmp;
+	biome = get_data(state, BIOMES, x, y, z);
+
+        if (biome >= NUM_BIOMES) {
+            biome = DEFAULT_BIOME;
+        }
+
+        for (i = 0; (max_i == -1 || i < max_i) && biomes[i].biome != 255; i++) {
+            if (biomes[i].biome == biome) {
+                *r = biomes[i].r;
+                *g = biomes[i].g;
+                *b = biomes[i].b;
+                
+                tmp = (128 - y_max + y) * 2 - 40;
+                *a = MIN(MAX(0, tmp), 255);
+                
+                max_i = i;
+                break;
+            }
+        }
+    }
+}
+
+static int
+overlay_biomes_start(void *data, RenderState *state, PyObject *support) {
+    PyObject *opt;
+    RenderPrimitiveBiomes* self;
+
+    /* first, chain up */
+    int ret = primitive_overlay.start(data, state, support);
+    if (ret != 0)
+        return ret;
+    
+    /* now do custom initializations */
+    self = (RenderPrimitiveBiomes *)data;
+    
+    // opt is a borrowed reference.  do not deref 
+    if (!render_mode_parse_option(support, "biomes", "O", &(opt)))
+        return 1;
+    if (opt && opt != Py_None) {
+        struct BiomeColor *biomes = NULL;
+        Py_ssize_t biomes_size = 0, i;
+        /* create custom biomes */
+        
+        if (!PyList_Check(opt)) {
+            PyErr_SetString(PyExc_TypeError, "'biomes' must be a list");
+            return 1;
+        }
+        
+        biomes_size = PyList_GET_SIZE(opt);
+        biomes = self->biomes = calloc(biomes_size + 1, sizeof(struct BiomeColor));
+        if (biomes == NULL) {
+            return 1;
+        }
+        
+        for (i = 0; i < biomes_size; i++) {
+            PyObject *biome = PyList_GET_ITEM(opt, i);
+            if (!PyArg_ParseTuple(biome, "b(bbb)", &(biomes[i].biome), &(biomes[i].r), &(biomes[i].g), &(biomes[i].b))) {
+                free(biomes);
+                self->biomes = NULL;
+                return 1;
+            }
+        }
+    } else {
+        self->biomes = default_biomes;
+    }
+    
+    /* setup custom color */
+    self->parent.get_color = get_color;
+    
+    return 0;
+}
+
+static void
+overlay_biomes_finish(void *data, RenderState *state) {
+    /* first free all *our* stuff */
+    RenderPrimitiveBiomes* self = (RenderPrimitiveBiomes *)data;
+    
+    if (self->biomes && self->biomes != default_biomes) {
+        free(self->biomes);
+    }
+    
+    /* now, chain up */
+    primitive_overlay.finish(data, state);
+}
+
+RenderPrimitiveInterface primitive_overlay_biomes = {
+    "overlay-biomes",
+    sizeof(RenderPrimitiveBiomes),
+    overlay_biomes_start,
+    overlay_biomes_finish,
+    NULL,
+    NULL,
+    overlay_draw,
+};