/// <summary>
/// Draw a virtual object at a specific location on a specified plane.
/// This method is called when WorldRenderManager's OnDrawFrame.
/// </summary>
/// <param name="cameraView">The viewMatrix is a 4 * 4 matrix.</param>
/// <param name="cameraProjection">The ProjectionMatrix is a 4 * 4 matrix.</param>
/// <param name="lightIntensity">The lighting intensity.</param>
/// <param name="obj">The virtual object.</param>
public void OnDrawFrame(float[] cameraView, float[] cameraProjection, float lightIntensity, VirtualObject obj)
{
ShaderUtil.CheckGlError(TAG, "onDrawFrame start.");
mModelMatrixs = obj.GetModelAnchorMatrix();
Matrix.MultiplyMM(mModelViewMatrixs, 0, cameraView, 0, mModelMatrixs, 0);
Matrix.MultiplyMM(mModelViewProjectionMatrixs, 0, cameraProjection, 0, mModelViewMatrixs, 0);
GLES20.GlUseProgram(mGlProgram);
Matrix.MultiplyMV(mViewLightDirections, 0, mModelViewMatrixs, 0, LIGHT_DIRECTIONS, 0);
MatrixUtil.NormalizeVec3(mViewLightDirections);
// Light direction.
GLES20.GlUniform4f(mLightingParametersUniform,
mViewLightDirections[0], mViewLightDirections[1], mViewLightDirections[2], lightIntensity);
float[] objColors = obj.GetColor();
GLES20.GlUniform4fv(mColorUniform, 1, objColors, 0);
GLES20.GlActiveTexture(GLES20.GlTexture0);
GLES20.GlBindTexture(GLES20.GlTexture2d, mTextures[0]);
GLES20.GlUniform1i(mTextureUniform, 0);
GLES20.GlBindBuffer(GLES20.GlArrayBuffer, mVertexBufferId);
// The coordinate dimension of the read virtual object is 3.
GLES20.GlVertexAttribPointer(
mPositionAttribute, 3, GLES20.GlFloat, false, 0, 0);
// The dimension of the normal vector is 3.
GLES20.GlVertexAttribPointer(
mNormalAttribute, 3, GLES20.GlFloat, false, 0, mNormalsBaseAddress);
// The dimension of the texture coordinate is 2.
GLES20.GlVertexAttribPointer(
mTexCoordAttribute, 2, GLES20.GlFloat, false, 0, mTexCoordsBaseAddress);
GLES20.GlBindBuffer(GLES20.GlArrayBuffer, 0);
GLES20.GlUniformMatrix4fv(
mModelViewUniform, 1, false, mModelViewMatrixs, 0);
GLES20.GlUniformMatrix4fv(
mModelViewProjectionUniform, 1, false, mModelViewProjectionMatrixs, 0);
GLES20.GlEnableVertexAttribArray(mPositionAttribute);
GLES20.GlEnableVertexAttribArray(mNormalAttribute);
GLES20.GlEnableVertexAttribArray(mTexCoordAttribute);
GLES20.GlBindBuffer(GLES20.GlElementArrayBuffer, mIndexBufferId);
GLES20.GlDrawElements(GLES20.GlTriangles, mIndexCount, GLES20.GlUnsignedShort, 0);
GLES20.GlBindBuffer(GLES20.GlElementArrayBuffer, 0);
GLES20.GlDisableVertexAttribArray(mPositionAttribute);
GLES20.GlDisableVertexAttribArray(mNormalAttribute);
GLES20.GlDisableVertexAttribArray(mTexCoordAttribute);
GLES20.GlBindTexture(GLES20.GlTexture2d, 0);
ShaderUtil.CheckGlError(TAG, "onDrawFrame end.");
}
// Convert the input coordinates to the plane coordinate system.
private float[] CalculateScreenPos(float coordinateX, float coordinateY, float coordinateZ)
{
// The coordinates of the point are four-dimensional (x, y, z, w).
float[] vecs = new float[4];
vecs[0] = coordinateX;
vecs[1] = coordinateY;
vecs[2] = coordinateZ;
vecs[3] = 1.0f;
// Store the coordinate values in the clip coordinate system.
float[] rets = new float[4];
Matrix.MultiplyMV(rets, 0, mModelViewProjectionMatrixs, 0, vecs, 0);
// Divide by the w component of the coordinates.
rets[0] /= rets[3];
rets[1] /= rets[3];
rets[2] /= rets[3];
// In the current coordinate system, left is negative, right is positive, downward
// is positive, and upward is negative.Adding 1 to the left of the X coordinate is
// equivalent to moving the coordinate system leftwards. Such an operation on the Y
// axis is equivalent to moving the coordinate system upwards.
rets[0] += 1.0f;
rets[1] = 1.0f - rets[1];
// Convert to pixel coordinates.
rets[0] *= mWidth;
rets[1] *= mHeight;
// When the w component is set to 1, the xy component caused by coordinate system
// movement is eliminated and doubled.
rets[3] = 1.0f;
rets[0] /= 2.0f;
rets[1] /= 2.0f;
return(rets);
}
/**
* Draws the model.
*
* @param cameraView A 4x4 view matrix, in column-major order.
* @param cameraPerspective A 4x4 projection matrix, in column-major order.
* @param lightIntensity Illumination intensity. Combined with diffuse and specular material
* properties.
* @see #setBlendMode(BlendMode)
* @see #updateModelMatrix(float[], float)
* @see #setMaterialProperties(float, float, float, float)
* @see android.opengl.Matrix
*/
public void Draw(float[] cameraView, float[] cameraPerspective, float lightIntensity)
{
ShaderUtil.CheckGLError(TAG, "Before draw");
// Build the ModelView and ModelViewProjection matrices
// for calculating object position and light.
Matrix.MultiplyMM(mModelViewMatrix, 0, cameraView, 0, mModelMatrix, 0);
Matrix.MultiplyMM(mModelViewProjectionMatrix, 0, cameraPerspective, 0, mModelViewMatrix, 0);
GLES20.GlUseProgram(mProgram);
// Set the lighting environment properties.
Matrix.MultiplyMV(mViewLightDirection, 0, mModelViewMatrix, 0, LIGHT_DIRECTION, 0);
normalizeVec3(mViewLightDirection);
GLES20.GlUniform4f(mLightingParametersUniform,
mViewLightDirection[0], mViewLightDirection[1], mViewLightDirection[2], lightIntensity);
// Set the object material properties.
GLES20.GlUniform4f(mMaterialParametersUniform, mAmbient, mDiffuse, mSpecular,
mSpecularPower);
// Attach the object texture.
GLES20.GlActiveTexture(GLES20.GlTexture0);
GLES20.GlBindTexture(GLES20.GlTexture2d, mTextures[0]);
GLES20.GlUniform1i(mTextureUniform, 0);
// Set the vertex attributes.
GLES20.GlBindBuffer(GLES20.GlArrayBuffer, mVertexBufferId);
GLES20.GlVertexAttribPointer(
mPositionAttribute, COORDS_PER_VERTEX, GLES20.GlFloat, false, 0, mVerticesBaseAddress);
GLES20.GlVertexAttribPointer(
mNormalAttribute, 3, GLES20.GlFloat, false, 0, mNormalsBaseAddress);
GLES20.GlVertexAttribPointer(
mTexCoordAttribute, 2, GLES20.GlFloat, false, 0, mTexCoordsBaseAddress);
GLES20.GlBindBuffer(GLES20.GlArrayBuffer, 0);
// Set the ModelViewProjection matrix in the shader.
GLES20.GlUniformMatrix4fv(
mModelViewUniform, 1, false, mModelViewMatrix, 0);
GLES20.GlUniformMatrix4fv(
mModelViewProjectionUniform, 1, false, mModelViewProjectionMatrix, 0);
// Enable vertex arrays
GLES20.GlEnableVertexAttribArray(mPositionAttribute);
GLES20.GlEnableVertexAttribArray(mNormalAttribute);
GLES20.GlEnableVertexAttribArray(mTexCoordAttribute);
if (mBlendMode != BlendMode.Null)
{
GLES20.GlDepthMask(false);
GLES20.GlEnable(GLES20.GlBlend);
switch (mBlendMode)
{
case BlendMode.Shadow:
// Multiplicative blending function for Shadow.
GLES20.GlBlendFunc(GLES20.GlZero, GLES20.GlOneMinusSrcAlpha);
break;
case BlendMode.Grid:
// Grid, additive blending function.
GLES20.GlBlendFunc(GLES20.GlSrcAlpha, GLES20.GlOneMinusSrcAlpha);
break;
}
}
GLES20.GlBindBuffer(GLES20.GlElementArrayBuffer, mIndexBufferId);
GLES20.GlDrawElements(GLES20.GlTriangles, mIndexCount, GLES20.GlUnsignedShort, 0);
GLES20.GlBindBuffer(GLES20.GlElementArrayBuffer, 0);
if (mBlendMode != BlendMode.Null)
{
GLES20.GlDisable(GLES20.GlBlend);
GLES20.GlDepthMask(true);
}
// Disable vertex arrays
GLES20.GlDisableVertexAttribArray(mPositionAttribute);
GLES20.GlDisableVertexAttribArray(mNormalAttribute);
GLES20.GlDisableVertexAttribArray(mTexCoordAttribute);
GLES20.GlBindTexture(GLES20.GlTexture2d, 0);
ShaderUtil.CheckGLError(TAG, "After draw");
}
