terrain_tessellation: Started new tessellation system

src/rendering/terrain/public.h

@@ -62,7 +62,6 @@ extern StandardDefinition TerrainDefinitionClass;
 extern StandardRenderer TerrainRendererClass;
 
 void terrainAutoPreset(TerrainDefinition* definition, TerrainPreset preset);
-void terrainRenderSurface(Renderer* renderer);
 double terrainGetGridHeight(TerrainDefinition* definition, int x, int z, int with_painting);
 double terrainGetInterpolatedHeight(TerrainDefinition* definition, double x, double z, int scaled, int with_painting);
 size_t terrainGetMemoryStats(TerrainDefinition* definition);

src/rendering/terrain/ter_raster.c

@@ -1,5 +1,6 @@
 #include "public.h"
 #include "private.h"
+#include "ter_raster.h"
 
 #include <stdlib.h>
 #include "../renderer.h"
@@ -34,7 +35,7 @@ static void _renderQuad(Renderer* renderer, double x, double z, double size, dou
     Vector3 ov1, ov2, ov3, ov4;
     Vector3 dv1, dv2, dv3, dv4;
 
-    ov1.y = ov2.y = ov3.y = ov4.y;
+    ov1.y = ov2.y = ov3.y = ov4.y = 0.0;
 
     ov1.x = x;
     ov1.z = z;
@@ -58,56 +59,103 @@ static void _renderQuad(Renderer* renderer, double x, double z, double size, dou
     }
 }
 
-void terrainRenderSurface(Renderer* renderer)
+void terrainTessellateChunk(Renderer* renderer, TerrainChunkInfo* chunk, int detail)
 {
+    /* TODO Tessellate ! */
+    _renderQuad(renderer, chunk->point_nw.x, chunk->point_nw.z, chunk->point_ne.x - chunk->point_nw.x, renderer->water->getHeightInfo(renderer).min_height);
+}
+
+static void _getChunk(Renderer* renderer, TerrainChunkInfo* chunk, double x, double z, double size, double water_height, int displaced)
+{
+    chunk->point_nw = renderer->terrain->getResult(renderer, x, z, 1, displaced).location;
+    chunk->point_sw = renderer->terrain->getResult(renderer, x, z + size, 1, displaced).location;
+    chunk->point_se = renderer->terrain->getResult(renderer, x + size, z + size, 1, displaced).location;
+    chunk->point_ne = renderer->terrain->getResult(renderer, x + size, z, 1, displaced).location;
+
+    /* TODO If displaced == 0, the detail_hint may be inaccurate (water and screen culling) */
+
+    if (chunk->point_nw.y >= water_height || chunk->point_sw.y >= water_height || chunk->point_se.y >= water_height || chunk->point_ne.y >= water_height)
+    {
+        /* TODO */
+        chunk->detail_hint = 5;
+    }
+    else
+    {
+        chunk->detail_hint = -1;
+    }
+}
+
+void terrainGetTessellationInfo(Renderer* renderer, FuncTerrainTessellationCallback callback, int displaced)
+{
+    TerrainChunkInfo chunk;
     int chunk_factor, chunk_count, i;
     Vector3 cam = renderer->getCameraLocation(renderer, VECTOR_ZERO);
     double cx = cam.x;
     double cz = cam.z;
-    double min_chunk_size, visible_chunk_size;
-    double radius_int, radius_ext, chunk_size;
     double water_height;
+    double progress;
+    double radius_int, radius_ext;
+    double base_chunk_size, chunk_size;
 
-    min_chunk_size = 0.2 / (double)renderer->render_quality;
-    visible_chunk_size = 0.1 / (double)renderer->render_quality;
-    if (renderer->render_quality > 7)
-    {
-        min_chunk_size *= 0.25;
-        visible_chunk_size *= 0.25;
-    }
+    base_chunk_size = 5.0 / (double)renderer->render_quality;
 
     chunk_factor = 1;
     chunk_count = 2;
     radius_int = 0.0;
-    radius_ext = min_chunk_size;
-    chunk_size = min_chunk_size;
+    radius_ext = base_chunk_size;
+    chunk_size = base_chunk_size;
+    progress = 0.0; /* TODO */
 
-    water_height = renderer->water->getHeightInfo(renderer).max_height;
+    water_height = renderer->water->getHeightInfo(renderer).min_height;
 
     while (radius_int < 5000.0)
     {
-        if (!renderer->addRenderProgress(renderer, 0.0))
-        {
-            return;
-        }
-
         for (i = 0; i < chunk_count - 1; i++)
         {
-            _renderQuad(renderer, cx - radius_ext + chunk_size * i, cz - radius_ext, chunk_size, water_height);
-            _renderQuad(renderer, cx + radius_int, cz - radius_ext + chunk_size * i, chunk_size, water_height);
-            _renderQuad(renderer, cx + radius_int - chunk_size * i, cz + radius_int, chunk_size, water_height);
-            _renderQuad(renderer, cx - radius_ext, cz + radius_int - chunk_size * i, chunk_size, water_height);
+            _getChunk(renderer, &chunk, cx - radius_ext + chunk_size * i, cz - radius_ext, chunk_size, water_height, displaced);
+            if (!callback(renderer, &chunk, progress))
+            {
+                return;
+            }
+
+            _getChunk(renderer, &chunk, cx + radius_int, cz - radius_ext + chunk_size * i, chunk_size, water_height, displaced);
+            if (!callback(renderer, &chunk, progress))
+            {
+                return;
+            }
+
+            _getChunk(renderer, &chunk, cx + radius_int - chunk_size * i, cz + radius_int, chunk_size, water_height, displaced);
+            if (!callback(renderer, &chunk, progress))
+            {
+                return;
+            }
+
+            _getChunk(renderer, &chunk, cx - radius_ext, cz + radius_int - chunk_size * i, chunk_size, water_height, displaced);
+            if (!callback(renderer, &chunk, progress))
+            {
+                return;
+            }
         }
 
-        if (chunk_count % 64 == 0 && chunk_size / radius_int < visible_chunk_size)
+        if (radius_int > 20.0 && chunk_count % 64 == 0 && (double)chunk_factor < radius_int / 20.0)
         {
             chunk_count /= 2;
             chunk_factor *= 2;
-            /* TODO Fill in gaps with triangles */
         }
         chunk_count += 2;
-        chunk_size = min_chunk_size * chunk_factor;
+        chunk_size = base_chunk_size * chunk_factor;
         radius_int = radius_ext;
         radius_ext += chunk_size;
     }
 }
+
+static int _standardTessellationCallback(Renderer* renderer, TerrainChunkInfo* chunk, double progress)
+{
+    terrainTessellateChunk(renderer, chunk, chunk->detail_hint);
+    return !renderer->render_interrupt;
+}
+
+void terrainRenderSurface(Renderer* renderer)
+{
+    terrainGetTessellationInfo(renderer, _standardTessellationCallback, 0);
+}

src/rendering/terrain/ter_raster.h

@@ -0,0 +1,42 @@
+#ifndef _RENDERING_TERRAIN_RASTER_H_
+#define _RENDERING_TERRAIN_RASTER_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct
+{
+    Vector3 point_nw;
+    Vector3 point_sw;
+    Vector3 point_se;
+    Vector3 point_ne;
+    int detail_hint;
+} TerrainChunkInfo;
+
+typedef int (*FuncTerrainTessellationCallback)(Renderer* renderer, TerrainChunkInfo* chunk, double progress);
+
+/**
+ * Tessellate the terrain, yielding chunks information.
+ *
+ * The terrain will be broken in chunks, most detailed near the camera.
+ */
+void terrainGetTessellationInfo(Renderer* renderer, FuncTerrainTessellationCallback callback, int displaced);
+
+/**
+ * Tessellate a terrain chunk, pushing the quads in the render area.
+ */
+void terrainTessellateChunk(Renderer* renderer, TerrainChunkInfo* chunk, int detail);
+
+/**
+ * Start the final rasterization of terrain.
+ *
+ * This will push the rasterized quads in the render area, waiting for post process.
+ */
+void terrainRenderSurface(Renderer* renderer);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif