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fix z-fighting on overlapping buildings:

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- modify projection matrix to add offset, glPolygonOffset is not that reliable
This commit is contained in:
Hannes Janetzek 2013-01-11 22:27:16 +01:00
parent d1388660a1
commit 007ab2e3bf
2 changed files with 29 additions and 16 deletions
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34
src/org/oscim/renderer/overlays/ExtrusionOverlay.java
View File

@ -161,6 +161,8 @@ public class ExtrusionOverlay extends RenderOverlay {
@Override
public synchronized void render(MapPosition pos, float[] mv, float[] proj) {
// TODO one could render in one pass to texture and then draw the texture
// with alpha... might be faster.
Matrix.multiplyMM(mVPMatrix, 0, proj, 0, pos.viewMatrix, 0);
proj = mVPMatrix;
@ -189,7 +191,7 @@ public class ExtrusionOverlay extends RenderOverlay {
for (int i = 0; i < mTileCnt; i++) {
ExtrusionLayer el = (ExtrusionLayer) tiles[i].layers.extrusionLayers;
setMatrix(pos, mv, proj, tiles[i], div);
setMatrix(pos, mv, proj, tiles[i], div, 0);
GLES20.glUniformMatrix4fv(uExtMatrix, 1, false, mv, 0);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, el.mIndicesBufferID);
@ -226,7 +228,6 @@ public class ExtrusionOverlay extends RenderOverlay {
GLState.enableVertexArrays(uExtVertexPosition, -1);
GLES20.glEnable(GLES20.GL_CULL_FACE);
GLES20.glCullFace(GLES20.GL_FRONT);
GLES20.glEnable(GLES20.GL_POLYGON_OFFSET_FILL);
GLES20.glDepthFunc(GLES20.GL_LESS);
GLES20.glColorMask(false, false, false, false);
GLES20.glUniform1i(uExtMode, 0);
@ -237,11 +238,8 @@ public class ExtrusionOverlay extends RenderOverlay {
for (int i = 0; i < mTileCnt; i++) {
MapTile t = tiles[i];
ExtrusionLayer el = (ExtrusionLayer) t.layers.extrusionLayers;
int add = GLRenderer.depthOffset(t);
GLES20.glPolygonOffset(2, add);
//GLES20.glPolygonOffset(1, i * 4 + 10);
setMatrix(pos, mv, proj, t, div);
int d = GLRenderer.depthOffset(t) * 10;
setMatrix(pos, mv, proj, t, div, d);
GLES20.glUniformMatrix4fv(uExtMatrix, 1, false, mv, 0);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, el.mIndicesBufferID);
@ -263,12 +261,10 @@ public class ExtrusionOverlay extends RenderOverlay {
for (int i = 0; i < mTileCnt; i++) {
MapTile t = tiles[i];
ExtrusionLayer el = (ExtrusionLayer) t.layers.extrusionLayers;
GLES20.glDepthFunc(GLES20.GL_EQUAL);
int add = GLRenderer.depthOffset(t);
GLES20.glPolygonOffset(2, add);
//GLES20.glPolygonOffset(1, i * 4 + 10);
setMatrix(pos, mv, proj, t, div);
GLES20.glDepthFunc(GLES20.GL_EQUAL);
int d = GLRenderer.depthOffset(t) * 10;
setMatrix(pos, mv, proj, t, div, d);
GLES20.glUniformMatrix4fv(uExtMatrix, 1, false, mv, 0);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, el.mIndicesBufferID);
@ -295,7 +291,11 @@ public class ExtrusionOverlay extends RenderOverlay {
GLES20.glDrawElements(GLES20.GL_TRIANGLES, el.mIndiceCnt[1],
GLES20.GL_UNSIGNED_SHORT, el.mIndiceCnt[0] * 2);
// drawing gl_lines with the same coordinates does not result in
// same depth values as polygons, so add offset and draw gl_lequal:
GLES20.glDepthFunc(GLES20.GL_LEQUAL);
GlUtils.addOffsetM(mv, 1000);
GLES20.glUniformMatrix4fv(uExtMatrix, 1, false, mv, 0);
GLES20.glUniform1i(uExtMode, 3);
GLES20.glDrawElements(GLES20.GL_LINES, el.mIndiceCnt[3],
@ -307,12 +307,11 @@ public class ExtrusionOverlay extends RenderOverlay {
}
GLES20.glDisable(GLES20.GL_CULL_FACE);
GLES20.glDisable(GLES20.GL_POLYGON_OFFSET_FILL);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, 0);
}
private static void setMatrix(MapPosition mapPosition, float[] matrix, float[] proj,
MapTile tile, float div) {
MapTile tile, float div, int delta) {
float x = (float) (tile.pixelX - mapPosition.x * div);
float y = (float) (tile.pixelY - mapPosition.y * div);
@ -323,6 +322,8 @@ public class ExtrusionOverlay extends RenderOverlay {
matrix[10] = scale / (1000f * GLRenderer.COORD_MULTIPLIER);
Matrix.multiplyMM(matrix, 0, proj, 0, matrix, 0);
GlUtils.addOffsetM(matrix, delta);
}
private final float _a = 0.8f;
@ -353,6 +354,7 @@ public class ExtrusionOverlay extends RenderOverlay {
(_r - _o) / 255,
(_g - _o) / 255,
(_b - _o) / 255,
// 1, 0, 0,
1.0f,
};
@ -441,9 +443,9 @@ public class ExtrusionOverlay extends RenderOverlay {
// + "varying float z;"
// + "void main() {"
// + "if (z < 0.0)"
// + " gl_FragColor = vec4(z * -1.0, 0.0, 0.0, 1.0)*0.8;"
// + " gl_FragColor = vec4(z * -1.0, 0.0, 0.0, 1.0);"
// + "else"
// + " gl_FragColor = vec4(0.0, 0.0, z, 1.0)*0.8;"
// + " gl_FragColor = vec4(0.0, 0.0, z, 1.0);"
// + "}";
public void setAlpha(float a) {

11
src/org/oscim/utils/GlUtils.java
View File

@ -230,4 +230,15 @@ public class GlUtils {
matrix[5] = sy;
matrix[10] = sz;
}
public static void addOffsetM(float[] matrix, int delta) {
// from http://www.mathfor3dgameprogramming.com/code/Listing9.1.cpp
// float n = MapViewPosition.VIEW_NEAR;
// float f = MapViewPosition.VIEW_FAR;
// float pz = 1;
// float epsilon = -2.0f * f * n * delta / ((f + n) * pz * (pz + delta));
float epsilon = 1.0f / (1 << 11);
matrix[10] *= 1.0f + epsilon * delta;
}
}