overlays converted into render primitives

overviewer_core/src/primitives/overlay.c

@@ -0,0 +1,118 @@
+/* 
+ * 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"
+
+static void get_color(void *data, RenderState *state,
+                      unsigned char *r, unsigned char *g, unsigned char *b, unsigned char *a) {
+    *r = 200;
+    *g = 200;
+    *b = 255;
+    *a = 155;
+}
+
+static int
+overlay_start(void *data, RenderState *state, PyObject *support) {
+    PyObject *facemasks_py;
+    RenderPrimitiveOverlay *self = (RenderPrimitiveOverlay *)data;
+    
+    self->facemask_top = PyObject_GetAttrString(support, "facemask_top");
+    self->white_color = PyObject_GetAttrString(support, "whitecolor");
+    self->get_color = get_color;
+    
+    return 0;
+}
+
+static void
+overlay_finish(void *data, RenderState *state) {
+    RenderPrimitiveOverlay *self = (RenderPrimitiveOverlay *)data;
+    
+    Py_DECREF(self->facemask_top);
+    Py_DECREF(self->white_color);
+}
+
+int
+overlay_occluded(void *data, RenderState *state, int x, int y, int z) {
+    if ( (x != 0) && (y != 15) && (z != 127) &&
+         !render_mode_hidden(state->rendermode, x-1, y, z) &&
+         !render_mode_hidden(state->rendermode, x, y, z+1) &&
+         !render_mode_hidden(state->rendermode, x, y+1, z) &&
+         !is_transparent(getArrayByte3D(state->blocks, x-1, y, z)) &&
+         !is_transparent(getArrayByte3D(state->blocks, x, y, z+1)) &&
+         !is_transparent(getArrayByte3D(state->blocks, x, y+1, z))) {
+        return 1;
+    }
+    
+    return 0;
+}
+
+void
+overlay_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    RenderPrimitiveOverlay *self = (RenderPrimitiveOverlay *)data;
+    unsigned char r, g, b, a;
+
+    // exactly analogous to edge-line code for these special blocks
+    int increment=0;
+    if (state->block == 44)  // half-step
+        increment=6;
+    else if (state->block == 78) // snow
+        increment=9;
+    
+    /* clear the draw space -- set alpha to 0 within mask */
+    tint_with_mask(state->img, 255, 255, 255, 0, mask, state->imgx, state->imgy, 0, 0);
+
+    /* skip rendering the overlay if we can't see it */
+    if (state->z != 127) {
+        unsigned char top_block = getArrayByte3D(state->blocks, state->x, state->y, state->z+1);
+        if (!is_transparent(top_block)) {
+            return;
+        }
+        
+        /* check to be sure this block is solid/fluid */
+        if (block_has_property(top_block, SOLID) || block_has_property(top_block, FLUID)) {
+            
+            /* top block is fluid or solid, skip drawing */
+            return;
+        }
+    }
+    
+    /* check to be sure this block is solid/fluid */
+    if (!block_has_property(state->block, SOLID) && !block_has_property(state->block, FLUID)) {
+        
+        /* not fluid or solid, skip drawing the overlay */
+        return;
+    }
+
+    /* get our color info */
+    self->get_color(data, state, &r, &g, &b, &a);
+    
+    /* do the overlay */
+    if (a > 0) {
+        alpha_over(state->img, self->white_color, self->facemask_top, state->imgx, state->imgy + increment, 0, 0);
+        tint_with_mask(state->img, r, g, b, a, self->facemask_top, state->imgx, state->imgy + increment, 0, 0);
+    }
+}
+
+RenderPrimitiveInterface primitive_overlay = {
+    "overlay",
+    sizeof(RenderPrimitiveOverlay),
+    overlay_start,
+    overlay_finish,
+    overlay_occluded,
+    NULL,
+    overlay_draw,
+};