ProgramVertex.java revision 2123b46ba85adb2cfb78068f8368e830640118d3 
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     * @hide
59     */
60    public int getInputCount() {
61        return mInputs != null ? mInputs.length : 0;
62    }
63
64    /**
65     * @hide
66     */
67    public Element getInput(int slot) {
68        if (slot < 0 || slot >= mInputs.length) {
69            throw new IllegalArgumentException("Slot ID out of range.");
70        }
71        return mInputs[slot];
72    }
73
74    /**
75    * Builder class for creating ProgramVertex objects.
76    * The builder starts empty and the user must minimally provide
77    * the GLSL shader code, and the varying inputs. Constant, or
78    * uniform parameters to the shader may optionally be provided as
79    * well.
80    *
81    **/
82    public static class Builder extends BaseProgramBuilder {
83        /**
84         * Create a builder object.
85         *
86         * @param rs Context to which the program will belong.
87         */
88        public Builder(RenderScript rs) {
89            super(rs);
90        }
91
92        /**
93         * Add varying inputs to the program
94         *
95         * @param e element describing the layout of the varying input
96         *          structure
97         * @return  self
98         */
99        public Builder addInput(Element e) throws IllegalStateException {
100            // Should check for consistant and non-conflicting names...
101            if(mInputCount >= MAX_INPUT) {
102                throw new RSIllegalArgumentException("Max input count exceeded.");
103            }
104            if (e.isComplex()) {
105                throw new RSIllegalArgumentException("Complex elements not allowed.");
106            }
107            mInputs[mInputCount++] = e;
108            return this;
109        }
110
111        /**
112         * Creates ProgramVertex from the current state of the builder
113         *
114         * @return  ProgramVertex
115         */
116        public ProgramVertex create() {
117            mRS.validate();
118            int[] tmp = new int[(mInputCount + mOutputCount + mConstantCount + mTextureCount) * 2];
119            String[] texNames = new String[mTextureCount];
120            int idx = 0;
121
122            for (int i=0; i < mInputCount; i++) {
123                tmp[idx++] = ProgramParam.INPUT.mID;
124                tmp[idx++] = mInputs[i].getID();
125            }
126            for (int i=0; i < mOutputCount; i++) {
127                tmp[idx++] = ProgramParam.OUTPUT.mID;
128                tmp[idx++] = mOutputs[i].getID();
129            }
130            for (int i=0; i < mConstantCount; i++) {
131                tmp[idx++] = ProgramParam.CONSTANT.mID;
132                tmp[idx++] = mConstants[i].getID();
133            }
134            for (int i=0; i < mTextureCount; i++) {
135                tmp[idx++] = ProgramParam.TEXTURE_TYPE.mID;
136                tmp[idx++] = mTextureTypes[i].mID;
137                texNames[i] = mTextureNames[i];
138            }
139
140            int id = mRS.nProgramVertexCreate(mShader, texNames, tmp);
141            ProgramVertex pv = new ProgramVertex(id, mRS);
142            initProgram(pv);
143            return pv;
144        }
145    }
146
147}
148