Question

我正在创建一个使用 OpenGL 3.3 的程序。我在程序中使用着色器，但它们似乎对我正在显示的三角形没有任何影响。他们正在加载和编译好。

我正在关注教程系列here。

Tutorial3.scala：

import org.lwjgl.opengl.Display
import org.lwjgl.opengl.DisplayMode
import org.lwjgl.opengl.PixelFormat
import org.lwjgl.opengl.ContextAttribs
import org.lwjgl.opengl.GL11
import org.lwjgl.opengl.GL20
import org.lwjgl.opengl.GL15
import org.lwjgl.opengl.GL30
import org.lwjgl.BufferUtils
import utils.Shader
import utils.ShaderProgram

class Tutorial3(WIDTH: Int, HEIGHT: Int, TITLE: String) extends utils.Disposable {

  /**
   * Create an Int VBO for our triangle
   */
  private var triangleVbo = 0
  /**
   * Create an Int VAO for our triangle
   */
  private var triangleVao = 0
  /**
   * Create a Float array for storing our triangle's vertices. 3 vertices, containing 3 values each (x,y,z)
   */
  private val triangleVertices: Array[Float] = new Array[Float](9)
  /**
   * Create a Float array for storing our trangle's colors
   */
  private val triangleColors: Array[Float] = new Array[Float](9)

  val vertexShader = new Shader()
  val fragmentShader = new Shader()
  val program = new ShaderProgram()

  setupOpenGl
  setupShapes

  while(!Display.isCloseRequested()) {
    loopCycle
    Display sync 60
    Display update
  }

  dispose

  private def setupOpenGl() {

     try {

       val pixelFormat = new PixelFormat
       val contextAttribs = new ContextAttribs(3, 3).withForwardCompatible(true).withProfileCore(true)
       Display setDisplayMode new DisplayMode(WIDTH, HEIGHT)
       Display setTitle TITLE
       Display create (pixelFormat, contextAttribs)

       GL11 glClearColor (1.0f, 0f, 0f, 1.0f)

     } catch {

       case e:Throwable => e printStackTrace; sys exit 1

     }

  }

  private def setupShapes() {

    //Triangle
    triangleVertices(0) = -0.5f
    triangleVertices(1) = -0.5f
    triangleVertices(2) = 0f

    triangleVertices(3) = 0.5f
    triangleVertices(4) = -0.5f
    triangleVertices(5) = 0f

    triangleVertices(6) = 0f
    triangleVertices(7) = 0.5f
    triangleVertices(8) = 0f

    //Colors
    triangleColors(0) = 1.0f
    triangleColors(1) = 0f
    triangleColors(2) = 0f

    triangleColors(3) = 0f
    triangleColors(4) = 1.0f
    triangleColors(5) = 0f

    triangleColors(6) = 0f
    triangleColors(7) = 0f
    triangleColors(8) = 1.0f

    val triangleBuffer = BufferUtils createFloatBuffer triangleVertices.length

    triangleBuffer put triangleVertices

    triangleBuffer flip ()

    triangleVao = GL30 glGenVertexArrays ()
    GL30 glBindVertexArray triangleVao

    triangleVbo = GL15 glGenBuffers ()
    GL15 glBindBuffer (GL15 GL_ARRAY_BUFFER, triangleVbo)
    GL15 glBufferData (GL15 GL_ARRAY_BUFFER, triangleBuffer, GL15 GL_STATIC_DRAW)

    GL20 glEnableVertexAttribArray 0
    GL20 glVertexAttribPointer (0, 3, GL11 GL_FLOAT, false, 0, 0)

    vertexShader loadShader ("vertex_shader_tutorial_3.glsl", GL20 GL_VERTEX_SHADER)
    fragmentShader loadShader ("fragment_shader_tutorial_3.glsl", GL20 GL_FRAGMENT_SHADER)

    program createProgram ()
    program addShader vertexShader
    program addShader fragmentShader

    program linkProgram ()
    program useProgram ()

    GL15 glBindBuffer (GL15 GL_ARRAY_BUFFER, 0)
    GL30 glBindVertexArray (0)

  }

  private def loopCycle() {
    //Do Drawing / Logic
    GL11 glClear (GL11 GL_COLOR_BUFFER_BIT)

    GL30 glBindVertexArray triangleVao
    GL20 glEnableVertexAttribArray 0

    GL11 glDrawArrays(GL11 GL_TRIANGLES, 0, triangleVertices length)

    GL20 glDisableVertexAttribArray 0
    GL30 glBindVertexArray 0
  }

  override def dispose() {
      GL20 glDisableVertexAttribArray 0

      GL15 glBindBuffer (GL15 GL_ARRAY_BUFFER, 0)
      GL15 glDeleteBuffers triangleVbo

      GL30 glBindVertexArray 0
      GL30 glDeleteVertexArrays triangleVao

      Display destroy
  }

}

object Tutorial3 {

  def main(args: Array[String]) {
    new Tutorial3(800, 600, "OpenGL 3.3 Tutorial 3")
  }

}

Shader.scala：

package utils

import java.io.File
import java.io.BufferedReader
import java.io.FileReader
import org.lwjgl.opengl.GL30
import org.lwjgl.opengl.GL15
import org.lwjgl.opengl.GL11
import org.lwjgl.opengl.GL20

class Shader extends Disposable {

  private var shader: Int = 0
  private var typ: Int = 0
  private var loaded: Boolean = false

  def loadShader(filename: String, typ: Int): Boolean = {

    val file: File = new File(System getProperty "user.dir", filename)

    if(!file.exists())
      false

    var line: String = ""
    val reader: BufferedReader = new BufferedReader(new FileReader(file))
    var shaderSource: String = ""

    while({line = reader.readLine(); line != null}) {
      shaderSource = shaderSource + line + "\n"
    }

    reader close

    this.shader = GL20 glCreateShader typ

    GL20 glShaderSource (this.shader, shaderSource)
    GL20 glCompileShader this.shader

    val status: Int = GL20 glGetShaderi(this.shader, GL20 GL_COMPILE_STATUS)

    if(status != 1)
      false

    this.typ = typ
    this.loaded = true

    true
  }

  def isLoaded(): Boolean = {
    this.loaded
  }

  def getShaderId(): Int = {
    this.shader
  }

  override def dispose() {
    GL20 glDeleteShader this.shader
  }

}

ShaderProgram.scala：

package utils

import org.lwjgl.opengl.GL20

class ShaderProgram extends Disposable {

  private var program: Int = 0
  private var linked: Int = 0

  def createProgram() {
    program = GL20 glCreateProgram
  }

  def useProgram() {
    GL20 glUseProgram this.program
  }

  def addShader(shader: Shader): Boolean = {
    GL20 glAttachShader(this.program, shader getShaderId)
    shader isLoaded
  }

  def linkProgram(): Boolean = {
    GL20 glLinkProgram this.program
    this.linked = GL20 glGetProgrami (this.program, GL20 GL_LINK_STATUS)
    this.linked != 0
  }

  def getProgramId(): Int = {
    this.program
  }

  override def dispose() {
    GL20 glDeleteProgram this.program
  }

}

顶点着色器：

#version 330

layout (location = 0) in vec3 inPosition;
layout (location = 1) in vec3 inColor;

smooth out vec3 theColor;

void main() {
    gl_Position = vec4(inPosition, 1.0);
    theColor = inColor;
}

Fragment Shader：

#version 330

smooth in vec3 theColor;
out vec4 outColor;

void main() {
    outColor = vec4(theColor, 1.0);
}

什么可能导致着色器不生效？

Answer 1

你只能打电话

GL20 glEnableVertexAttribArray 0

但你使用

layout (location = 0) in vec3 inPosition;
layout (location = 1) in vec3 inColor;

这让我觉得你也应该打电话

GL20 glEnableVertexAttribArray 1

除非我严重错误。

OpenGL着色器似乎不工作

Tutorial3.scala：

Shader.scala：

ShaderProgram.scala：

顶点着色器：

Fragment Shader：

1 个答案: