remove depth-buffer tile clipping

not needed anymore, yay!

vtm/src/org/oscim/renderer/elements/PolygonLayer.java

@@ -39,7 +39,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Special Renderer for drawing tile polygons
+ * Special Renderer for drawing tile polygons using a stencil buffer method
  */
 public final class PolygonLayer extends RenderElement {
 	static final Logger log = LoggerFactory.getLogger(PolygonLayer.class);
@@ -260,8 +260,9 @@ public final class PolygonLayer extends RenderElement {
 
 			GLState.enableVertexArrays(hPolygonVertexPosition[shader], -1);
 
-			GL.glVertexAttribPointer(hPolygonVertexPosition[shader], 2, GL20.GL_SHORT,
+			GL.glVertexAttribPointer(hPolygonVertexPosition[shader], 2,
-			                         false, 0, POLYGON_VERTICES_DATA_POS_OFFSET);
+			                         GL20.GL_SHORT, false, 0,
+			                         POLYGON_VERTICES_DATA_POS_OFFSET);
 
 			m.mvp.setAsUniform(hPolygonMatrix[shader]);
 		}
@@ -374,14 +375,6 @@ public final class PolygonLayer extends RenderElement {
 		 */
 		static void drawStencilRegion(boolean first) {
 
-			//		if (!first) {
-			//		 GL.glStencilMask(0x7F);
-			//			GL.glClear(GL20.GL_STENCIL_BUFFER_BIT);
-			//			// disable drawing to color buffer
-			//		 GL.glColorMask(false, false, false, false);
-			//		 GL.glStencilFunc(GL_EQUAL, CLIP_BIT, CLIP_BIT);
-			//		}
-
 			// disable drawing to color buffer
 			GL.glColorMask(false, false, false, false);
 
@@ -389,20 +382,6 @@ public final class PolygonLayer extends RenderElement {
 			GL.glStencilMask(0xFF);
 
 			if (first) {
-				// clear previous clip-region from stencil buffer
-				//GL.glClear(GL20.GL_STENCIL_BUFFER_BIT);
-
-				// Draw clip-region into depth and stencil buffer
-				// this is used for tile line and polygon layers.
-				// Depth offset is increased for each tile. Together
-				// with depth test (GL_LESS) this ensures to only
-				// draw where no other tile has drawn yet.
-				GL.glEnable(GL20.GL_POLYGON_OFFSET_FILL);
-
-				// test GL_LESS and write to depth buffer
-				GLState.test(true, true);
-				GL.glDepthMask(true);
-
 				// always pass stencil test and set clip bit
 				GL.glStencilFunc(GL20.GL_ALWAYS, CLIP_BIT, 0x00);
 			} else {
@@ -418,25 +397,18 @@ public final class PolygonLayer extends RenderElement {
 			GL.glDrawArrays(GL20.GL_TRIANGLE_STRIP, 0, 4);
 
 			if (first) {
-				// dont modify depth buffer
-				GL.glDepthMask(false);
-				// test only stencil
-				GLState.test(false, true);
-
-				GL.glDisable(GL20.GL_POLYGON_OFFSET_FILL);
-
 				GL.glStencilFunc(GL20.GL_EQUAL, CLIP_BIT, CLIP_BIT);
 			}
 		}
 
+		/**
+		 * Clear stencilbuffer for a tile region by drawing
+		 * a quad with func 'always' and op 'zero'. Using 'color'
+		 * and 'alpha' for a fake fade effect.
+		 */
 		public static void drawOver(Matrices m, int color, float alpha) {
 			setShader(polyShader, m);
 
-			/*
-			 * clear stencilbuffer (tile region) by drawing
-			 * a quad with func 'always' and op 'zero'
-			 */
-
 			if (color != 0) {
 				GLUtils.setColor(hPolygonColor[0], color, alpha);
 				GLState.blend(true);

vtm/src/org/oscim/tiling/TileRenderer.java

@@ -25,7 +25,6 @@ import org.oscim.core.MapPosition;
 import org.oscim.core.Tile;
 import org.oscim.renderer.BufferObject;
 import org.oscim.renderer.ElementRenderer;
-import org.oscim.renderer.GLMatrix;
 import org.oscim.renderer.LayerRenderer;
 import org.oscim.renderer.MapRenderer;
 import org.oscim.renderer.MapRenderer.Matrices;
@@ -361,15 +360,10 @@ public class TileRenderer extends LayerRenderer {
 		return maxFade;
 	}
 
-	// Counter increases polygon-offset for each tile drawn.
-	private int mOffsetCnt;
-
 	// Current number of frames drawn, used to not draw a
 	// tile twice per frame.
 	private int mDrawSerial = 0;
-
 	private Matrices mMatrices;
-	private final GLMatrix mProjMatrix = new GLMatrix();
 
 	/**
 	 * Draw tiles:
@@ -381,33 +375,23 @@ public class TileRenderer extends LayerRenderer {
 	 */
 	private void draw(MapTile[] tiles, int tileCnt, MapPosition pos, Matrices m) {
 
-		mOffsetCnt = -2048;
 		mMatrices = m;
 
-		mProjMatrix.copy(m.proj);
+		/** draw visible tiles */
-		// discard depth projection from tilt, we use depth buffer
-		// for clipping
-		mProjMatrix.setValue(10, 0);
-		mProjMatrix.setValue(14, 0);
-		mProjMatrix.multiplyRhs(m.view);
-
-		GL.glDepthMask(true);
-		GL.glClear(GL20.GL_DEPTH_BUFFER_BIT);
-		GL.glDepthFunc(GL20.GL_LESS);
-
-		// Draw visible tiles
 		for (int i = 0; i < tileCnt; i++) {
 			MapTile t = tiles[i];
 			if (t.isVisible && t.state == STATE_READY)
 				drawTile(t, pos);
 		}
 
+		/**
+		 * draw parent or children as proxy for visibile tiles that dont
+		 * have data yet. Proxies are clipped to the region where nothing
+		 * was drawn to depth buffer.
+		 * TODO draw proxies for placeholder
+		 */
 		double scale = pos.getZoomScale();
 
-		// Draw parent or children as proxy for visibile tiles that dont
-		// have data yet. Proxies are clipped to the region where nothing
-		// was drawn to depth buffer.
-		// TODO draw proxies for placeholder
 		for (int i = 0; i < tileCnt; i++) {
 			MapTile t = tiles[i];
 			if (t.isVisible && (t.state != STATE_READY) && (t.holder == null)) {
@@ -416,20 +400,18 @@ public class TileRenderer extends LayerRenderer {
 			}
 		}
 
-		// Draw grandparents
+		/** draw grandparents */
 		for (int i = 0; i < tileCnt; i++) {
 			MapTile t = tiles[i];
 			if (t.isVisible && (t.state != STATE_READY) && (t.holder == null))
 				drawProxyTile(t, pos, false, false);
 		}
 
-		// make sure stencil buffer write is disabled
+		/** make sure stencil buffer write is disabled */
 		GL.glStencilMask(0x00);
 		GL.glDepthMask(false);
 
 		mDrawSerial++;
-
-		// clear reference
 		mMatrices = null;
 	}
 
@@ -465,10 +447,7 @@ public class TileRenderer extends LayerRenderer {
 
 		Matrices m = mMatrices;
 		m.mvp.setTransScale(x, y, scale / MapRenderer.COORD_SCALE);
-		m.mvp.multiplyLhs(mProjMatrix);
+		m.mvp.multiplyLhs(m.viewproj);
-
-		// set depth offset (used for clipping to tile boundaries)
-		GL.glPolygonOffset(0, mOffsetCnt++);
 
 		boolean clipped = false;