OpenGL ES Android 2D 视图似乎被缩小到无穷大
OpenGL ES Android 2D view appears to be zoomed out to infinity
我有一个 Kotlin 沙盒应用程序可以在 Android Studio 中试验 OpenGL ES。我按照教程进行操作，成功创建了具有适当长宽比的三角形、直线和点。我正在为 Android 使用 OpenGL ES 2 这本书，并转换为 Kotlin。 Source code is available here.
我与本书不同，试图创建用于平移和缩放的 2D 可变换视图（目前我对 3D 功能不是很感兴趣）所以我引用了 Android Dev docs 和某处在混杂的代码中，我创建了一个错误。出现的是中心的一个点，尽管缩放并将点移动到不同的位置。这些点渲染是因为着色器是 10 像素，我怀疑三角形在那里但太小了。也许在管道的某个地方应用了 0 的比例？我尝试手动缩放 orthoM 视图，但它在非常极端的数字下没有效果。我将这些点从原点移开，所有的点在孤立时仍然出现在原点。所以我认为 0 缩放可能正在发生。
我的预期结果是看到点出现在 1.0f 和 -1.0f 之间，当 setLookAtM 和点顶点被这样定义时。
渲染器：
package com.e
import android.content.Context
import android.opengl.GLES20.*
import android.opengl.GLSurfaceView.Renderer
import android.opengl.Matrix
import android.opengl.Matrix.*
import com.e.mysandboxapplication.R
import util.LoggerConfig
import util.ShaderHelper
import util.TextResourceReaderService
import java.nio.ByteBuffer
import java.nio.ByteOrder
import java.nio.FloatBuffer
import javax.microedition.khronos.egl.EGLConfig
import javax.microedition.khronos.opengles.GL10
class Open2DMapGLRenderer (
private var context: Context
) : Renderer {
private val U_Matrix = "u_Matrix"
private var projectionMatrix = FloatArray(16)
private var viewMatrix = FloatArray(16)
private val vPMatrix = FloatArray(16)
private var vPMatrixHandle = 0
private var uMatrixLocation = 0
private val BYTES_PER_FLOAT = 4
private lateinit var vertexData : FloatBuffer
private var program = 0
private val u_Color = "u_Color"
private var uColorLocation = 0
private var a_Position = "a_Position"
private var aPositionLocation = 0
private var POSITION_COMPONENT_COUNT = 2
init{
val vertices = PopulateVertices()
vertexData = ByteBuffer.allocateDirect(vertices.count() * BYTES_PER_FLOAT)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
vertexData.put(vertices)
}
private fun PopulateVertices(): FloatArray {
val vertices = floatArrayOf(
// Triangle 1
-0.5f, -0.5f,
0.5f, 0.5f,
-0.5f, 0.5f,
// Triangle 2
-0.5f, -0.5f,
0.5f, -0.5f,
0.5f, 0.5f,
// Line 1
-0.5f, 0f,
0.5f, 0f,
// Points
0.5f, 0.5f,
-0.5f, -0.5f,
0.0f, 0.0f
)
return vertices
}
override fun onDrawFrame(gl: GL10?) {
glClear(GL_COLOR_BUFFER_BIT)
setLookAtM(viewMatrix, 0, 0f, 0f, 1.0f, 0f, 0f, 0f, 0f, 1.0f, 0f)
multiplyMM(vPMatrix, 0, projectionMatrix, 0, viewMatrix, 0)
vPMatrixHandle = glGetUniformLocation(program, "uMVPMatrix")
glUniformMatrix4fv(vPMatrixHandle, 1, false, vPMatrix, 0)
DrawTriangles()
DrawPoints()
DrawLines()
}
private fun DrawPoints() {
glUniform4f(uColorLocation, 1.0f, 1.0f, 1.0f, 1.0f)
glDrawArrays(GL_POINTS, 8, 3)
}
private fun DrawLines() {
glUniform4f(uColorLocation, 0f, 0f, 1.0f, 1.0f)
glDrawArrays(GL_LINES, 6, 2)
}
private fun DrawTriangles() {
glUniform4f(uColorLocation, 1.0f, 1.0f, 1.0f, 1.0f)
glDrawArrays(GL_TRIANGLES, 0, 6)
}
override fun onSurfaceChanged(gl: GL10?, width: Int, height: Int) {
var isPortrait = width > height
glViewport(0, 0, width, height)
var scale = 1.0f // added this for diagnostics. No apparent effect.
var aspectRatio = if ( isPortrait ) { width / height.toFloat() } else { height / width.toFloat() }
if (isPortrait) {
// Portrait
orthoM(projectionMatrix, 0, -aspectRatio * scale , aspectRatio * scale, -scale, scale, -2.0f, 2.0f)
}else{
// Landscape
orthoM(projectionMatrix, 0 , -scale, scale, -aspectRatio * scale , aspectRatio * scale, -2.0f, 2.0f)
}
}
override fun onSurfaceCreated(gl: GL10?, config: EGLConfig?) {
glClearColor(0.75f,0.75f,0.75f,1.0f)
val vertexShaderSource : String = TextResourceReaderService()
.readTextFileFromResource(context, R.raw.simple_vertex_shader)
val fragmentShaderSource : String = TextResourceReaderService()
.readTextFileFromResource(context, R.raw.simple_fragment_shader)
val vertexShader : Int = ShaderHelper().compileVertexShader(vertexShaderSource)
val fragmentShader : Int = ShaderHelper().compileFragmentShader(fragmentShaderSource)
program = ShaderHelper().linkProgram(vertexShader, fragmentShader)
if(LoggerConfig.ON) {
ShaderHelper().validateProgram(program)
}
glUseProgram(program)
uColorLocation = glGetUniformLocation(program, u_Color)
aPositionLocation = glGetAttribLocation(program, a_Position)
vertexData.position(0)
glVertexAttribPointer(aPositionLocation, POSITION_COMPONENT_COUNT, GL_FLOAT, false, 0, vertexData)
glEnableVertexAttribArray(aPositionLocation)
uMatrixLocation = glGetUniformLocation(program, U_Matrix)
}
}
ShaderHelper 实用程序Class:
import android.opengl.GLES20.*
import android.util.Log
public class ShaderHelper{
private val TAG : String = "ShaderHelper"
public fun compileVertexShader (shaderCode : String): Int{
return compileShader(GL_VERTEX_SHADER, shaderCode)
}
public fun compileFragmentShader (shaderCode : String): Int{
return compileShader(GL_FRAGMENT_SHADER, shaderCode)
}
private fun compileShader(type: Int , shaderCode: String) : Int{
val shaderObjectId : Int = glCreateShader(type)
if(shaderObjectId == 0){
if (LoggerConfig.ON){
Log.w(TAG, "Could not create new Shader.")
}
return 0
}
glShaderSource(shaderObjectId, shaderCode)
glCompileShader(shaderObjectId)
val compileStatus : IntArray = IntArray(1)
glGetShaderiv(shaderObjectId, GL_COMPILE_STATUS, compileStatus, 0 )
if(LoggerConfig.ON){
Log.v(TAG, "Results of compiling source: " + "\n" + shaderCode + "\n"
+ glGetShaderInfoLog(shaderObjectId))
}
if(compileStatus[0] == 0){
glDeleteShader(shaderObjectId)
Log.v(TAG, "Compilation of shader failed.")
return 0
}
return shaderObjectId
}
public fun linkProgram (vertexShaderId : Int, fragmentShaderId : Int) : Int {
val programObjectId : Int = glCreateProgram()
if(programObjectId == 0) {
if (LoggerConfig.ON) {
Log.v(TAG, "Could not create GL Program.")
}
return 0
}
glAttachShader(programObjectId, vertexShaderId)
glAttachShader(programObjectId, fragmentShaderId)
glLinkProgram(programObjectId)
val linkStatus : IntArray = IntArray(1)
glGetProgramiv(programObjectId, GL_LINK_STATUS, linkStatus, 0)
if (LoggerConfig.ON) {
// Print the program info log to the Android log output.
Log.v(TAG, "Results of linking program:\n"
+ glGetProgramInfoLog(programObjectId));
}
if(linkStatus[0] == 0) {
glDeleteProgram(programObjectId)
if(LoggerConfig.ON){
Log.v(TAG, "Linking of program failed.\n")
}
return 0
}
return programObjectId
}
public fun validateProgram(programObjectId : Int) : Boolean{
glValidateProgram(programObjectId)
val validateStatus = IntArray(1)
glGetProgramiv(programObjectId, GL_VALIDATE_STATUS, validateStatus, 0);
Log.v(TAG, "Results of validating program: " + validateStatus[0]
+ "\nLog:" + glGetProgramInfoLog(programObjectId));
return validateStatus[0] != 0;
}
}
顶点着色器：
uniform mat4 uMVPMatrix;
attribute vec4 v_Position;
void main()
{
gl_Position = uMVPMatrix * v_Position;
gl_PointSize = 10.0;
}
片段着色器：
precision mediump float;
uniform vec4 u_Color;
void main()
{
gl_FragColor = u_Color;
}
问题是顶点着色器位置的变量包含拼写错误。
private var a_Position = "a_Position"
不匹配着色器：
attribute vec4 v_Position;
导致包含在 0,0,0 的所有内容。
我有一个 Kotlin 沙盒应用程序可以在 Android Studio 中试验 OpenGL ES。我按照教程进行操作，成功创建了具有适当长宽比的三角形、直线和点。我正在为 Android 使用 OpenGL ES 2 这本书，并转换为 Kotlin。 Source code is available here.
我与本书不同，试图创建用于平移和缩放的 2D 可变换视图（目前我对 3D 功能不是很感兴趣）所以我引用了 Android Dev docs 和某处在混杂的代码中，我创建了一个错误。出现的是中心的一个点，尽管缩放并将点移动到不同的位置。这些点渲染是因为着色器是 10 像素，我怀疑三角形在那里但太小了。也许在管道的某个地方应用了 0 的比例？我尝试手动缩放 orthoM 视图，但它在非常极端的数字下没有效果。我将这些点从原点移开，所有的点在孤立时仍然出现在原点。所以我认为 0 缩放可能正在发生。
我的预期结果是看到点出现在 1.0f 和 -1.0f 之间，当 setLookAtM 和点顶点被这样定义时。
渲染器：
package com.e
import android.content.Context
import android.opengl.GLES20.*
import android.opengl.GLSurfaceView.Renderer
import android.opengl.Matrix
import android.opengl.Matrix.*
import com.e.mysandboxapplication.R
import util.LoggerConfig
import util.ShaderHelper
import util.TextResourceReaderService
import java.nio.ByteBuffer
import java.nio.ByteOrder
import java.nio.FloatBuffer
import javax.microedition.khronos.egl.EGLConfig
import javax.microedition.khronos.opengles.GL10
class Open2DMapGLRenderer (
private var context: Context
) : Renderer {
private val U_Matrix = "u_Matrix"
private var projectionMatrix = FloatArray(16)
private var viewMatrix = FloatArray(16)
private val vPMatrix = FloatArray(16)
private var vPMatrixHandle = 0
private var uMatrixLocation = 0
private val BYTES_PER_FLOAT = 4
private lateinit var vertexData : FloatBuffer
private var program = 0
private val u_Color = "u_Color"
private var uColorLocation = 0
private var a_Position = "a_Position"
private var aPositionLocation = 0
private var POSITION_COMPONENT_COUNT = 2
init{
val vertices = PopulateVertices()
vertexData = ByteBuffer.allocateDirect(vertices.count() * BYTES_PER_FLOAT)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
vertexData.put(vertices)
}
private fun PopulateVertices(): FloatArray {
val vertices = floatArrayOf(
// Triangle 1
-0.5f, -0.5f,
0.5f, 0.5f,
-0.5f, 0.5f,
// Triangle 2
-0.5f, -0.5f,
0.5f, -0.5f,
0.5f, 0.5f,
// Line 1
-0.5f, 0f,
0.5f, 0f,
// Points
0.5f, 0.5f,
-0.5f, -0.5f,
0.0f, 0.0f
)
return vertices
}
override fun onDrawFrame(gl: GL10?) {
glClear(GL_COLOR_BUFFER_BIT)
setLookAtM(viewMatrix, 0, 0f, 0f, 1.0f, 0f, 0f, 0f, 0f, 1.0f, 0f)
multiplyMM(vPMatrix, 0, projectionMatrix, 0, viewMatrix, 0)
vPMatrixHandle = glGetUniformLocation(program, "uMVPMatrix")
glUniformMatrix4fv(vPMatrixHandle, 1, false, vPMatrix, 0)
DrawTriangles()
DrawPoints()
DrawLines()
}
private fun DrawPoints() {
glUniform4f(uColorLocation, 1.0f, 1.0f, 1.0f, 1.0f)
glDrawArrays(GL_POINTS, 8, 3)
}
private fun DrawLines() {
glUniform4f(uColorLocation, 0f, 0f, 1.0f, 1.0f)
glDrawArrays(GL_LINES, 6, 2)
}
private fun DrawTriangles() {
glUniform4f(uColorLocation, 1.0f, 1.0f, 1.0f, 1.0f)
glDrawArrays(GL_TRIANGLES, 0, 6)
}
override fun onSurfaceChanged(gl: GL10?, width: Int, height: Int) {
var isPortrait = width > height
glViewport(0, 0, width, height)
var scale = 1.0f // added this for diagnostics. No apparent effect.
var aspectRatio = if ( isPortrait ) { width / height.toFloat() } else { height / width.toFloat() }
if (isPortrait) {
// Portrait
orthoM(projectionMatrix, 0, -aspectRatio * scale , aspectRatio * scale, -scale, scale, -2.0f, 2.0f)
}else{
// Landscape
orthoM(projectionMatrix, 0 , -scale, scale, -aspectRatio * scale , aspectRatio * scale, -2.0f, 2.0f)
}
}
override fun onSurfaceCreated(gl: GL10?, config: EGLConfig?) {
glClearColor(0.75f,0.75f,0.75f,1.0f)
val vertexShaderSource : String = TextResourceReaderService()
.readTextFileFromResource(context, R.raw.simple_vertex_shader)
val fragmentShaderSource : String = TextResourceReaderService()
.readTextFileFromResource(context, R.raw.simple_fragment_shader)
val vertexShader : Int = ShaderHelper().compileVertexShader(vertexShaderSource)
val fragmentShader : Int = ShaderHelper().compileFragmentShader(fragmentShaderSource)
program = ShaderHelper().linkProgram(vertexShader, fragmentShader)
if(LoggerConfig.ON) {
ShaderHelper().validateProgram(program)
}
glUseProgram(program)
uColorLocation = glGetUniformLocation(program, u_Color)
aPositionLocation = glGetAttribLocation(program, a_Position)
vertexData.position(0)
glVertexAttribPointer(aPositionLocation, POSITION_COMPONENT_COUNT, GL_FLOAT, false, 0, vertexData)
glEnableVertexAttribArray(aPositionLocation)
uMatrixLocation = glGetUniformLocation(program, U_Matrix)
}
}
ShaderHelper 实用程序Class:
import android.opengl.GLES20.*
import android.util.Log
public class ShaderHelper{
private val TAG : String = "ShaderHelper"
public fun compileVertexShader (shaderCode : String): Int{
return compileShader(GL_VERTEX_SHADER, shaderCode)
}
public fun compileFragmentShader (shaderCode : String): Int{
return compileShader(GL_FRAGMENT_SHADER, shaderCode)
}
private fun compileShader(type: Int , shaderCode: String) : Int{
val shaderObjectId : Int = glCreateShader(type)
if(shaderObjectId == 0){
if (LoggerConfig.ON){
Log.w(TAG, "Could not create new Shader.")
}
return 0
}
glShaderSource(shaderObjectId, shaderCode)
glCompileShader(shaderObjectId)
val compileStatus : IntArray = IntArray(1)
glGetShaderiv(shaderObjectId, GL_COMPILE_STATUS, compileStatus, 0 )
if(LoggerConfig.ON){
Log.v(TAG, "Results of compiling source: " + "\n" + shaderCode + "\n"
+ glGetShaderInfoLog(shaderObjectId))
}
if(compileStatus[0] == 0){
glDeleteShader(shaderObjectId)
Log.v(TAG, "Compilation of shader failed.")
return 0
}
return shaderObjectId
}
public fun linkProgram (vertexShaderId : Int, fragmentShaderId : Int) : Int {
val programObjectId : Int = glCreateProgram()
if(programObjectId == 0) {
if (LoggerConfig.ON) {
Log.v(TAG, "Could not create GL Program.")
}
return 0
}
glAttachShader(programObjectId, vertexShaderId)
glAttachShader(programObjectId, fragmentShaderId)
glLinkProgram(programObjectId)
val linkStatus : IntArray = IntArray(1)
glGetProgramiv(programObjectId, GL_LINK_STATUS, linkStatus, 0)
if (LoggerConfig.ON) {
// Print the program info log to the Android log output.
Log.v(TAG, "Results of linking program:\n"
+ glGetProgramInfoLog(programObjectId));
}
if(linkStatus[0] == 0) {
glDeleteProgram(programObjectId)
if(LoggerConfig.ON){
Log.v(TAG, "Linking of program failed.\n")
}
return 0
}
return programObjectId
}
public fun validateProgram(programObjectId : Int) : Boolean{
glValidateProgram(programObjectId)
val validateStatus = IntArray(1)
glGetProgramiv(programObjectId, GL_VALIDATE_STATUS, validateStatus, 0);
Log.v(TAG, "Results of validating program: " + validateStatus[0]
+ "\nLog:" + glGetProgramInfoLog(programObjectId));
return validateStatus[0] != 0;
}
}
顶点着色器：
uniform mat4 uMVPMatrix;
attribute vec4 v_Position;
void main()
{
gl_Position = uMVPMatrix * v_Position;
gl_PointSize = 10.0;
}
片段着色器：
precision mediump float;
uniform vec4 u_Color;
void main()
{
gl_FragColor = u_Color;
}
问题是顶点着色器位置的变量包含拼写错误。
private var a_Position = "a_Position"
不匹配着色器：
attribute vec4 v_Position;
导致包含在 0,0,0 的所有内容。