kotlin
复制代码
class MyDrawData2 {
private var mProgram: Int = -1
private var NO_OFFSET = 0
private val VERTEX_POS_DATA_SIZE = 3
private val TEXTURE_POS_DATA_SIZE = 2
private val STRIDE = (VERTEX_POS_DATA_SIZE + TEXTURE_POS_DATA_SIZE) * 4 // 每个顶点的总字节数
// VAO(Vertex Array Object), 顶点数组对象, 用于存储VBO
private var mVAO = IntArray(1)
// VBO(Vertex Buffer Object), 顶点缓冲对象，用于存储顶点数据和纹理数据
private var mVBO = IntArray(1) // 只需要一个VBO
// IBO(Index Buffer Object), 索引缓冲对象，用于存储顶点索引数据
private var mIBO = IntArray(1)
// 纹理ID
private var mTextureID = IntArray(1)
// 最终变换矩阵
private var mMVPMatrix = FloatArray(16)
// 投影矩阵
private val mProjectionMatrix = FloatArray(16)
// 视图矩阵
private val mViewMatrix = FloatArray(16)
// 模型矩阵
private val mModelMatrix = FloatArray(16)
// 视口比例
private var mViewPortRatio = 1f
// 顶点和纹理坐标合并在一个数组中
// 格式：x, y, z, u, v (顶点坐标后跟纹理坐标)
val vertexData = floatArrayOf(
// 顶点坐标 // 纹理坐标
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f, // 左上
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f, // 左下
1.0f, 1.0f, 0.0f, 1.0f, 1.0f, // 右上
1.0f, -1.0f, 0.0f, 1.0f, 0.0f // 右下
)
val vertexDataBuffer = ByteBuffer.allocateDirect(vertexData.size * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
.put(vertexData)
.position(NO_OFFSET)
val index = shortArrayOf(
0, 1, 2, // 第一个三角形
1, 3, 2 // 第二个三角形
)
val indexBuffer = ByteBuffer.allocateDirect(index.size * 2)
.order(ByteOrder.nativeOrder())
.asShortBuffer()
.put(index)
.position(NO_OFFSET)
// 初始化着色器程序
fun initShaderProgram() {
val vertexShaderCode = """#version 300 es
uniform mat4 uMVPMatrix; // 变换矩阵
in vec4 aPosition; // 顶点坐标
in vec2 aTexCoord; // 纹理坐标
out vec2 vTexCoord;
void main() {
// 输出顶点坐标和纹理坐标到片段着色器
gl_Position = uMVPMatrix * aPosition;
vTexCoord = aTexCoord;
}""".trimIndent()
val fragmentShaderCode = """#version 300 es
precision mediump float;
uniform sampler2D uTexture_0;
in vec2 vTexCoord;
out vec4 fragColor;
void main() {
fragColor = texture(uTexture_0, vTexCoord);
}""".trimIndent()
// 加载顶点着色器和片段着色器, 并创建着色器程序
val vertexShader = LoadShaderUtil.loadShader(GLES30.GL_VERTEX_SHADER, vertexShaderCode)
val fragmentShader = LoadShaderUtil.loadShader(GLES30.GL_FRAGMENT_SHADER, fragmentShaderCode)
mProgram = GLES30.glCreateProgram()
GLES30.glAttachShader(mProgram, vertexShader)
GLES30.glAttachShader(mProgram, fragmentShader)
GLES30.glLinkProgram(mProgram)
// 删除着色器对象
GLES30.glDeleteShader(vertexShader)
GLES30.glDeleteShader(fragmentShader)
}
// 创建VAO, VBO, IBO
fun initVertexBuffer() {
// 绑定VAO
GLES30.glGenVertexArrays(mVAO.size, mVAO, NO_OFFSET)
GLES30.glBindVertexArray(mVAO[0])
// 绑定VBO - 只需要一个VBO存储所有数据
GLES30.glGenBuffers(mVBO.size, mVBO, NO_OFFSET)
GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, mVBO[0])
GLES30.glBufferData(
GLES30.GL_ARRAY_BUFFER,
vertexData.size * 4,
vertexDataBuffer,
GLES30.GL_STATIC_DRAW
)
// 设置顶点属性指针 - 顶点坐标
val positionHandle = GLES30.glGetAttribLocation(mProgram, "aPosition")
GLES30.glEnableVertexAttribArray(positionHandle)
GLES30.glVertexAttribPointer(
positionHandle,
VERTEX_POS_DATA_SIZE,
GLES30.GL_FLOAT,
false,
STRIDE, // 步长，每个顶点5个float (x,y,z,u,v)
NO_OFFSET // 偏移量，位置数据在前
)
// 设置顶点属性指针 - 纹理坐标
val textureHandle = GLES30.glGetAttribLocation(mProgram, "aTexCoord")
GLES30.glEnableVertexAttribArray(textureHandle)
GLES30.glVertexAttribPointer(
textureHandle,
TEXTURE_POS_DATA_SIZE,
GLES30.GL_FLOAT,
false,
STRIDE, // 步长，每个顶点5个float (x,y,z,u,v)
VERTEX_POS_DATA_SIZE * 4 // 偏移量，纹理数据在位置数据之后
)
// 绑定IBO
GLES30.glGenBuffers(mIBO.size, mIBO, NO_OFFSET)
// 绑定索引缓冲区数据到IBO[0]
GLES30.glBindBuffer(GLES30.GL_ELEMENT_ARRAY_BUFFER, mIBO[0])
GLES30.glBufferData(
GLES30.GL_ELEMENT_ARRAY_BUFFER,
index.size * 2,
indexBuffer,
GLES30.GL_STATIC_DRAW
)
// 解绑VAO
GLES30.glBindVertexArray(0)
// 解绑VBO和IBO
GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, 0)
GLES30.glBindBuffer(GLES30.GL_ELEMENT_ARRAY_BUFFER, 0)
}
// 使用着色器程序绘制图形
fun drawSomething(program: Int, mvpMatrix: FloatArray) {
// 解析变换矩阵
val matrixHandle = GLES30.glGetUniformLocation(program, "uMVPMatrix")
GLES30.glUniformMatrix4fv(matrixHandle, 1, false, mvpMatrix, NO_OFFSET)
// 绑定VAO
GLES30.glBindVertexArray(mVAO[0])
// 绘制图形
GLES30.glDrawElements(
GLES30.GL_TRIANGLES,
index.size,
GLES30.GL_UNSIGNED_SHORT,
NO_OFFSET
)
// 解绑VAO
GLES30.glBindVertexArray(0)
}
fun resetMatrix() {
Matrix.setIdentityM(mModelMatrix, NO_OFFSET)
Matrix.setIdentityM(mViewMatrix, NO_OFFSET)
Matrix.setIdentityM(mProjectionMatrix, NO_OFFSET)
Matrix.setIdentityM(mMVPMatrix, NO_OFFSET)
}
// 计算GLSurfaceView变换矩阵
fun computeMVPMatrix(width: Int, height: Int) {
val isLandscape = width > height
mViewPortRatio = if (isLandscape) width.toFloat() / height else height.toFloat() / width
// 计算包围图片的球半径
val radius = sqrt(1f + mViewPortRatio * mViewPortRatio)
val near = 0.1f
val far = near + 2 * radius
val distance = near / (near + radius)
// 视图矩阵View Matrix
Matrix.setLookAtM(
mViewMatrix, NO_OFFSET,
0f, 0f, near + radius, // 相机位置
0f, 0f, 0f, // 看向原点
0f, 1f, 0f // 上方向
)
// 投影矩阵Projection Matrix
Matrix.frustumM(
mProjectionMatrix, NO_OFFSET,
if (isLandscape) (-mViewPortRatio * distance) else (-1f * distance), // 左边界
if (isLandscape) (mViewPortRatio * distance) else (1f * distance), // 右边界
if (isLandscape) (-1f * distance) else (-mViewPortRatio * distance), // 下边界
if (isLandscape) (1f * distance) else (mViewPortRatio * distance), // 上边界
near, // 近平面
far // 远平面
)
// 最终变换矩阵，第一次变换，模型矩阵 x 视图矩阵 = Model x View, 但是OpenGL ES矩阵乘法是右乘，所以是View x Model
Matrix.multiplyMM(
mMVPMatrix,
NO_OFFSET,
mViewMatrix,
NO_OFFSET,
mModelMatrix,
NO_OFFSET
)
// 最终变换矩阵，第二次变换，模型矩阵 x 视图矩阵 x 投影矩阵 = Model x View x Projection, 但是OpenGL ES矩阵乘法是右乘，所以是Projection x View x Model
Matrix.multiplyMM(
mMVPMatrix,
NO_OFFSET,
mProjectionMatrix,
NO_OFFSET,
mMVPMatrix,
NO_OFFSET
)
// 纹理坐标系为(0, 0), (1, 0), (1, 1), (0, 1)的正方形逆时针坐标系，从Bitmap生成纹理，即像素拷贝到纹理坐标系
// 变换矩阵需要加上一个y方向的翻转, x方向和z方向不改变
Matrix.scaleM(
mMVPMatrix,
NO_OFFSET,
1f,
-1f,
1f,
)
}
// 加载纹理
fun loadTexture(context: Context, resourceId: Int): Int {
val textureId = IntArray(1)
// 生成纹理
GLES30.glGenTextures(1, textureId, 0)
// 绑定纹理
GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, textureId[0])
// 设置纹理参数
GLES30.glTexParameteri(
GLES30.GL_TEXTURE_2D,
GLES30.GL_TEXTURE_MIN_FILTER,
GLES30.GL_LINEAR
) // 纹理缩小时使用线性插值
GLES30.glTexParameteri(
GLES30.GL_TEXTURE_2D,
GLES30.GL_TEXTURE_MAG_FILTER,
GLES30.GL_LINEAR
) // 纹理放大时使用线性插值
GLES30.glTexParameteri(
GLES30.GL_TEXTURE_2D,
GLES30.GL_TEXTURE_WRAP_S,
GLES30.GL_CLAMP_TO_EDGE
) // 纹理坐标超出范围时，超出部分使用最边缘像素进行填充
GLES30.glTexParameteri(
GLES30.GL_TEXTURE_2D,
GLES30.GL_TEXTURE_WRAP_T,
GLES30.GL_CLAMP_TO_EDGE
) // 纹理坐标超出范围时，超出部分使用最边缘像素进行填充
// 加载图片
val options = BitmapFactory.Options().apply {
inScaled = false // 不进行缩放
}
val bitmap = BitmapFactory.decodeResource(context.resources, resourceId, options)
// 将图片数据加载到纹理中
GLUtils.texImage2D(GLES30.GL_TEXTURE_2D, 0, bitmap, 0)
// 释放资源
bitmap.recycle()
// 解绑纹理
GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, 0)
Log.e(
"yang",
"loadTexture: 纹理加载成功 bitmap.width:${bitmap.width} bitmap.height:${bitmap.height}"
)
return textureId[0]
}
fun enableTexture0(program: Int, id: Int) {
GLES30.glActiveTexture(GLES30.GL_TEXTURE0)
GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, id)
val textureSampleHandle = GLES30.glGetUniformLocation(program, "uTexture_0")
if (textureSampleHandle != -1) {
GLES30.glUniform1i(textureSampleHandle, 0)
}
}
fun disableTexture0() {
GLES30.glActiveTexture(GLES30.GL_TEXTURE0)
GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, 0)
}
fun initTexture0(context: Context, resourceId: Int) {
mTextureID[0] = loadTexture(context, resourceId)
}
// GLSurfaceView实时绘制
fun drawCurrentOutput() {
val state = saveGLState()
try {
GLES30.glUseProgram(mProgram)
enableTexture0(mProgram, mTextureID[0])
drawSomething(mProgram, mMVPMatrix)
disableTexture0()
} finally {
restoreGLState(state)
}
}
// 保存OpenGL状态
private fun saveGLState(): GLState {
val viewport = IntArray(4)
val program = IntArray(1)
val framebuffer = IntArray(1)
GLES30.glGetIntegerv(GLES30.GL_VIEWPORT, viewport, 0)
GLES30.glGetIntegerv(GLES30.GL_CURRENT_PROGRAM, program, 0)
GLES30.glGetIntegerv(GLES30.GL_FRAMEBUFFER_BINDING, framebuffer, 0)
return GLState(viewport, program[0], framebuffer[0])
}
// 恢复OpenGL状态
private fun restoreGLState(state: GLState) {
GLES30.glViewport(
state.viewport[0],
state.viewport[1],
state.viewport[2],
state.viewport[3]
)
GLES30.glUseProgram(state.program)
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, state.framebuffer)
}
// OpenGL状态数据类
data class GLState(
val viewport: IntArray,
val program: Int,
val framebuffer: Int
)
object LoadShaderUtil {
// 创建着色器对象
fun loadShader(type: Int, source: String): Int {
val shader = GLES30.glCreateShader(type)
GLES30.glShaderSource(shader, source)
GLES30.glCompileShader(shader)
return shader
}
}
}
kotlin
复制代码
// 创建VAO, VBO, IBO
fun initVertexBuffer() {
// 绑定VAO
GLES30.glGenVertexArrays(mVAO.size, mVAO, NO_OFFSET)
GLES30.glBindVertexArray(mVAO[0])
// 绑定VBO - 只需要一个VBO存储所有数据
GLES30.glGenBuffers(mVBO.size, mVBO, NO_OFFSET)
GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, mVBO[0])
GLES30.glBufferData(
GLES30.GL_ARRAY_BUFFER,
vertexData.size * 4,
vertexDataBuffer,
GLES30.GL_STATIC_DRAW
)
// 设置顶点属性指针 - 顶点坐标
val positionHandle = GLES30.glGetAttribLocation(mProgram, "aPosition")
GLES30.glEnableVertexAttribArray(positionHandle)
GLES30.glVertexAttribPointer(
positionHandle,
VERTEX_POS_DATA_SIZE,
GLES30.GL_FLOAT,
false,
STRIDE, // 步长，每个顶点5个float (x,y,z,u,v)
NO_OFFSET // 偏移量，位置数据在前
)
// 设置顶点属性指针 - 纹理坐标
val textureHandle = GLES30.glGetAttribLocation(mProgram, "aTexCoord")
GLES30.glEnableVertexAttribArray(textureHandle)
GLES30.glVertexAttribPointer(
textureHandle,
TEXTURE_POS_DATA_SIZE,
GLES30.GL_FLOAT,
false,
STRIDE, // 步长，每个顶点5个float (x,y,z,u,v)
VERTEX_POS_DATA_SIZE * 4 // 偏移量，纹理数据在位置数据之后
)
// 绑定IBO
GLES30.glGenBuffers(mIBO.size, mIBO, NO_OFFSET)
// 绑定索引缓冲区数据到IBO[0]
GLES30.glBindBuffer(GLES30.GL_ELEMENT_ARRAY_BUFFER, mIBO[0])
GLES30.glBufferData(
GLES30.GL_ELEMENT_ARRAY_BUFFER,
index.size * 2,
indexBuffer,
GLES30.GL_STATIC_DRAW
)
// 解绑VAO
GLES30.glBindVertexArray(0)
// 解绑VBO和IBO
GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, 0)
GLES30.glBindBuffer(GLES30.GL_ELEMENT_ARRAY_BUFFER, 0)
}
