private static int usableMaxUniformVectors(GL20 gl) {
// this returns the maximum number of vec4s; then we subtract one vec2 to account for the
// uHScreenSize uniform, and two more because some GPUs seem to need one for our vec3 attr
int maxVecs = gl.glGetInteger(GL_MAX_VERTEX_UNIFORM_VECTORS) - 3;
gl.checkError("glGetInteger(GL_MAX_VERTEX_UNIFORM_VECTORS)");
return maxVecs;
}
/** Creates a uniform quad batch with the supplied custom shader program builder. */
public UniformQuadBatch(GL20 gl, Source source) {
super(gl);
int maxVecs = usableMaxUniformVectors(gl) - extraVec4s();
if (maxVecs < vec4sPerQuad())
throw new RuntimeException(
"GL_MAX_VERTEX_UNIFORM_VECTORS too low: have "
+ maxVecs
+ ", need at least "
+ vec4sPerQuad());
maxQuads = maxVecs / vec4sPerQuad();
program = new GLProgram(gl, source.vertex(this), source.fragment());
uTexture = program.getUniformLocation("u_Texture");
uHScreenSize = program.getUniformLocation("u_HScreenSize");
uFlip = program.getUniformLocation("u_Flip");
uData = program.getUniformLocation("u_Data");
aVertex = program.getAttribLocation("a_Vertex");
// create our stock supply of unit quads and stuff them into our buffers
short[] verts = new short[maxQuads * VERTICES_PER_QUAD * VERTEX_SIZE];
short[] elems = new short[maxQuads * ELEMENTS_PER_QUAD];
int vv = 0, ee = 0;
for (short ii = 0; ii < maxQuads; ii++) {
verts[vv++] = 0;
verts[vv++] = 0;
verts[vv++] = ii;
verts[vv++] = 1;
verts[vv++] = 0;
verts[vv++] = ii;
verts[vv++] = 0;
verts[vv++] = 1;
verts[vv++] = ii;
verts[vv++] = 1;
verts[vv++] = 1;
verts[vv++] = ii;
short base = (short) (ii * VERTICES_PER_QUAD);
short base0 = base, base1 = ++base, base2 = ++base, base3 = ++base;
elems[ee++] = base0;
elems[ee++] = base1;
elems[ee++] = base2;
elems[ee++] = base1;
elems[ee++] = base3;
elems[ee++] = base2;
}
data = new float[maxQuads * vec4sPerQuad() * 4];
// create our GL buffers
int[] ids = new int[2];
gl.glGenBuffers(2, ids, 0);
verticesId = ids[0];
elementsId = ids[1];
gl.glBindBuffer(GL_ARRAY_BUFFER, verticesId);
gl.bufs.setShortBuffer(verts, 0, verts.length);
gl.glBufferData(GL_ARRAY_BUFFER, verts.length * 2, gl.bufs.shortBuffer, GL_STATIC_DRAW);
gl.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementsId);
gl.bufs.setShortBuffer(elems, 0, elems.length);
gl.glBufferData(GL_ELEMENT_ARRAY_BUFFER, elems.length * 2, gl.bufs.shortBuffer, GL_STATIC_DRAW);
gl.checkError("UniformQuadBatch end ctor");
}