ProgramVertex.java revision 43a17654cf4bfe7f1ec22bd8b7b32daccdf27c09 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /**
18 * <p>The Renderscript vertex program, also known as a vertex shader, describes a stage in
19 * the graphics pipeline responsible for manipulating geometric data in a user-defined way.
20 * The object is constructed by providing the Renderscript system with the following data:</p>
21 * <ul>
22 *   <li>Element describing its varying inputs or attributes</li>
23 *   <li>GLSL shader string that defines the body of the program</li>
24 *   <li>a Type that describes the layout of an Allocation containing constant or uniform inputs</li>
25 * </ul>
26 *
27 * <p>Once the program is created, you bind it to the graphics context, RenderScriptGL, and it will be used for
28 * all subsequent draw calls until you bind a new program. If the program has constant inputs,
29 * the user needs to bind an allocation containing those inputs. The allocation's type must match
30 * the one provided during creation. The Renderscript library then does all the necessary plumbing
31 * to send those constants to the graphics hardware. Varying inputs to the shader, such as position, normal,
32 * and texture coordinates are matched by name between the input Element and the Mesh object being drawn.
33 * The signatures don't have to be exact or in any strict order. As long as the input name in the shader
34 * matches a channel name and size available on the mesh, the runtime takes care of connecting the
35 * two. Unlike OpenGL, there is no need to link the vertex and fragment programs.</p>
36 *
37 **/
38package android.renderscript;
39
40
41import android.graphics.Matrix;
42import android.util.Log;
43
44
45/**
46 * ProgramVertex, also know as a vertex shader, describes a
47 * stage in the graphics pipeline responsible for manipulating
48 * geometric data in a user-defined way.
49 *
50 **/
51public class ProgramVertex extends Program {
52
53    ProgramVertex(int id, RenderScript rs) {
54        super(id, rs);
55    }
56
57    /**
58    * Builder class for creating ProgramVertex objects.
59    * The builder starts empty and the user must minimally provide
60    * the GLSL shader code, and the varying inputs. Constant, or
61    * uniform parameters to the shader may optionally be provided as
62    * well.
63    *
64    **/
65    public static class Builder extends BaseProgramBuilder {
66        /**
67         * Create a builder object.
68         *
69         * @param rs Context to which the program will belong.
70         */
71        public Builder(RenderScript rs) {
72            super(rs);
73        }
74
75        /**
76         * Add varying inputs to the program
77         *
78         * @param e element describing the layout of the varying input
79         *          structure
80         * @return  self
81         */
82        public Builder addInput(Element e) throws IllegalStateException {
83            // Should check for consistant and non-conflicting names...
84            if(mInputCount >= MAX_INPUT) {
85                throw new RSIllegalArgumentException("Max input count exceeded.");
86            }
87            if (e.isComplex()) {
88                throw new RSIllegalArgumentException("Complex elements not allowed.");
89            }
90            mInputs[mInputCount++] = e;
91            return this;
92        }
93
94        /**
95         * Creates ProgramVertex from the current state of the builder
96         *
97         * @return  ProgramVertex
98         */
99        public ProgramVertex create() {
100            mRS.validate();
101            int[] tmp = new int[(mInputCount + mOutputCount + mConstantCount + mTextureCount) * 2];
102            int idx = 0;
103
104            for (int i=0; i < mInputCount; i++) {
105                tmp[idx++] = ProgramParam.INPUT.mID;
106                tmp[idx++] = mInputs[i].getID();
107            }
108            for (int i=0; i < mOutputCount; i++) {
109                tmp[idx++] = ProgramParam.OUTPUT.mID;
110                tmp[idx++] = mOutputs[i].getID();
111            }
112            for (int i=0; i < mConstantCount; i++) {
113                tmp[idx++] = ProgramParam.CONSTANT.mID;
114                tmp[idx++] = mConstants[i].getID();
115            }
116            for (int i=0; i < mTextureCount; i++) {
117                tmp[idx++] = ProgramParam.TEXTURE_TYPE.mID;
118                tmp[idx++] = mTextureTypes[i].mID;
119            }
120
121            int id = mRS.nProgramVertexCreate(mShader, tmp);
122            ProgramVertex pv = new ProgramVertex(id, mRS);
123            initProgram(pv);
124            return pv;
125        }
126    }
127
128}
129