由於tve和what_nick在該主題中的貢獻,結果相當簡單:GLSL Shader support that renders tiles correctly。具體來說,我重用了tve貢獻的GLSL類(在shader_support_051308.zip中)並修改了what_nick的示例代碼。
我定義了一個DecoratedLayer類,允許任何一層被「裝飾」以新的渲染策略,然後定義一個ShadingDecorator是委託給底層的render
方法之前設置的GLSL着色器:
public class DecoratedLayer implements Layer {
private final Layer _layer;
private final I_LayerDecorator _decorator;
public DecoratedLayer(Layer layer, I_LayerDecorator decorator) {
_layer = layer;
_decorator = decorator;
}
@Override
public void preRender(DrawContext dc) {
_decorator.preRender(dc, _layer);
}
@Override
public void render(DrawContext dc) {
_decorator.render(dc, _layer);
}
// all other methods delegate to _layer
}
public class ShadingDecorator implements I_LayerDecorator {
private GLSL glsl;
private final File vertfile;
private final File fragfile;
public ShadingDecorator(final File vertexShaderFile,
final File fragmentShaderFile) {
vertfile = vertexShaderFile;
fragfile = fragmentShaderFile;
}
@Override
public void preRender(DrawContext dc, Layer layer) {
if (glsl == null) {
glsl = new GLSL(dc.getGL());
glsl.loadVertexShader(vertfile);
glsl.loadFragmentShader(fragfile);
}
layer.preRender(dc);
}
@Override
public void render(DrawContext dc, Layer layer) {
if (glsl != null) {
glsl.useShaders();
glsl.startShader();
GL gl = dc.getGL();
gl.glUniform1i(glsl.getUniformLocation("tile_image"), 0);
layer.render(dc);
glsl.endShader();
}
}
}
需要做更多的工作才能做到這一點,但這應該是一個合理的出發點。
對響應非常感興趣 - 我在工作中使用WorldWind的應用程序,但從未想過使用自定義着色器。 – I82Much 2011-02-04 02:07:59