OpenGL ES 2 - 不显示纹理
OpenGL ES 2 - Textures Are Not Displayed
在我重构代码以显示多个不同的纹理之前，一切都运行良好，但现在我得到的只是比它们应该的尺寸小的黑框，显然它们没有任何纹理！我什至没有触及顶点，我根本不知道为什么尺寸会受到影响。
截图（黑色的大方块应该已经覆盖了整个屏幕，底部的小方块应该更大了。不知道是什么影响了它们的大小） :
着色器：（它们在使用前编译）
const val vertexShader_Image = "uniform mat4 u_MVPMatrix;" +
"attribute vec4 a_Position;" +
"attribute vec2 a_texCoord;" +
"varying vec2 v_texCoord;" +
"void main() {" +
" gl_Position = u_MVPMatrix * a_Position;" +
" v_texCoord = a_texCoord;" +
"}"
const val fragmentShader_Image = "precision mediump float;" +
"uniform sampler2D u_texture;" +
"varying vec2 v_texCoord;" +
"void main() {" +
" gl_FragColor = texture2D(u_texture, v_texCoord);" +
"}"
TextureLoader：（对象在Kotlin中基本上是静态的class如果你不熟悉的话）
object TextureLoader
{
var textures: Map<TextureName, Int> = mutableMapOf()
fun generateTextures(nameBitmapPair: List<Pair<TextureName, Bitmap>>, screenWidth: Int, screenHeight: Int)
{
val textureAmount = nameBitmapPair.size
val mutableTextureMap = mutableMapOf<TextureName, Int>()
if(textureAmount > 31 || textureAmount< 0)
{
throw IllegalStateException("Texture amount is bigger than 31 or smaller than 0. Texture limit for OPEN GL is 31, it can't be bigger than it")
}
val textureHandles = IntArray(textureAmount)
GLES20.glGenTextures(textureAmount, textureHandles, 0)
for (i in 0 until textureAmount)
{
if (textureHandles[i] != 0)
{
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR)
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR)
// Load the bitmap into the bound texture.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, nameBitmapPair.get(i).second, 0)
nameBitmapPair.get(i).second.recycle()
mutableTextureMap.put(nameBitmapPair.get(i).first, textureHandles[i])
Timber.i("created new texture, Name = ${nameBitmapPair.get(i).first}, ID = ${textureHandles[i]}")
}
else
{
throw RuntimeException("Error loading texture.")
}
}
textures = mutableTextureMap
}
}
Batcher：（处理 OpenGL 样板代码的 class 因此代码库的其余部分不会让任何人眼花缭乱）
class Batcher private constructor()
{
// Store the model matrix. This matrix is used to move models from object space (where each model can be thought
// of being located at the center of the universe) to world space.
private val mtrxModel = FloatArray(16)
// Allocate storage for the final combined matrix. This will be passed into the shader program.
private val mtrxMVP = FloatArray(16)
// Store the projection matrix. This is used to project the scene onto a 2D viewport.
private val mtrxProjection = FloatArray(16)
/* This was my UV array before I refactored the code to add animations. Now it's accessed by the
sprite.animator.getUvCoordinationForCurrentFrame()
private var uvArray = floatArrayOf(
0.0f, 0.0f,
0.0f, 0.20f,
0.20f, 0.20f,
0.20f, 0.0f)
*/
private var uvBuffer: FloatBuffer? = null
private var vertexBuffer: FloatBuffer? = null
private var indices = shortArrayOf(0, 1, 2, 0, 2, 3) // The order of vertexrendering.
private var indicesBuffer: ShortBuffer? = null
// NOTE: companion object is the static class of the Kotlin if you are not familiar with it. It's used to create a singleton here.
companion object
{
private var instance: Batcher? = null
fun getInstance(): Batcher
{
if (instance == null)
{
instance = Batcher()
}
return instance!!
}
}
//Constructor of the Kotlin classes if you aren't familiar with it
init
{
glEnable(GL_BLEND)
// initialize byte buffer for the draw list
indicesBuffer = ByteBuffer.allocateDirect(indices.size * 2)
.order(ByteOrder.nativeOrder())
.asShortBuffer()
indicesBuffer!!.put(indices)
.position(0)
val vertices = floatArrayOf(
0f, 0f, 0f,
0f, 1.0f, 0f,
1.0f, 1.0f, 0f,
1.0f, 0f, 0f)
// The vertex buffer.
vertexBuffer = ByteBuffer.allocateDirect(vertices.size * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
vertexBuffer!!.put(vertices)
.position(0)
}
fun render(sprites: Sprites)
{
//TODO should these be called on every draw call??
// Get handle to shape's transformation matrix
val u_MVPMatrix = glGetUniformLocation(ShaderHelper.programTexture, "u_MVPMatrix")
val a_Position = glGetAttribLocation(ShaderHelper.programTexture, "a_Position")
val a_texCoord = glGetAttribLocation(ShaderHelper.programTexture, "a_texCoord")
val u_texture = glGetUniformLocation(ShaderHelper.programTexture, "u_texture")
glEnableVertexAttribArray(a_Position)
glEnableVertexAttribArray(a_texCoord)
// "it" here is the currently iterated sprite object
sprites.forEach{
val uvArray = it.animator.getUvCoordinationForCurrentFrame()
if (uvArray != null)
{
updateUVBuffer(uvArray)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
// Matrix op - start
Matrix.setIdentityM(mtrxMVP, 0)
Matrix.setIdentityM(mtrxModel, 0)
Matrix.translateM(mtrxModel, 0, it.x.toFloat(), it.y.toFloat(), 0f)
Matrix.scaleM(mtrxModel, 0, it.scaledFrameWidth.toFloat(), it.scaledFrameHeight.toFloat(), 0f)
if (it.isHorizontallyFlipped)
{
Matrix.translateM(mtrxModel, 0, 1f, 0f, 0f)
Matrix.scaleM(mtrxModel, 0, -1f, 1f, 0f)
}
Matrix.multiplyMM(mtrxMVP, 0, mtrxModel, 0, mtrxMVP, 0)
Matrix.multiplyMM(mtrxMVP, 0, mtrxProjection, 0, mtrxMVP, 0)
// Matrix op - end
// Pass the data to shaders - start
// Prepare the triangle coordinate data
//Binds this vertex's data to a spot in the buffer
glVertexAttribPointer(a_Position, 3, GL_FLOAT, false, 0, vertexBuffer)
// Prepare the texture coordinates
glVertexAttribPointer(a_texCoord, 2, GL_FLOAT, false, 0, uvBuffer)
glUniformMatrix4fv(u_MVPMatrix, 1, false, mtrxMVP, 0)
// Set the sampler texture unit to where we have saved the texture.
// second param is the active texture index
glUniform1i(u_texture, TextureLoader.textures.get(it.textureName)!!)
// Draw the triangles
glDrawElements(GL_TRIANGLES, indices.size, GL_UNSIGNED_SHORT, indicesBuffer)
}
else
{
Timber.w("UV array of the sprite is null, skipping rendering. \nSprite: ${it}")
}
}
}
fun setScreenDimension(screenWidth: Int, screenHeight: Int)
{
Matrix.setIdentityM(mtrxProjection, 0)
Matrix.orthoM(mtrxProjection, 0, 0f, screenWidth.toFloat(), screenHeight.toFloat(), 0f, 0f, 1f)
}
private fun updateUVBuffer(uvArray: FloatArray)
{
uvBuffer = ByteBuffer.allocateDirect(uvArray.size * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
uvBuffer!!.put(uvArray)
.position(0)
}
要分配给纹理采样器统一的值不是纹理的对象编号。它必须是纹理绑定到的纹理单元。由于您的纹理绑定到纹理单元 0 (GL_TEXTURE0)，因此您需要将 0 分配给纹理采样器统一（默认为 0）：
glUniform1i(u_texture, TextureLoader.textures.get(it.textureName)!!)
glUniform1i(u_texture, 0)
glBindTexture binds a texture to the specified target and the current texture unit. The texture unit can be set by glActiveTexture.
如果你这样做
glActiveTexture(GLES20.GL_TEXTURE0)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
然后你必须将 0 分配给纹理采样器。但如果你这样做
glActiveTexture(GLES20.GL_TEXTURE1)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
然后你必须将1分配给纹理采样器。
在绘制网格之前必须确保纹理已绑定。由于您有不同的纹理，因此每次要渲染具有纹理的几何体时都应调用 glBindTexture：例如：
glActiveTexture(GLES20.GL_TEXTURE0)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, TextureLoader.textures.get(it.textureName)!!)
glUniform1i(u_texture, 0)
glDrawElements(GL_TRIANGLES, indices.size, GL_UNSIGNED_SHORT, indicesBuffer)
在我重构代码以显示多个不同的纹理之前，一切都运行良好，但现在我得到的只是比它们应该的尺寸小的黑框，显然它们没有任何纹理！我什至没有触及顶点，我根本不知道为什么尺寸会受到影响。
截图（黑色的大方块应该已经覆盖了整个屏幕，底部的小方块应该更大了。不知道是什么影响了它们的大小） :
着色器：（它们在使用前编译）
const val vertexShader_Image = "uniform mat4 u_MVPMatrix;" +
"attribute vec4 a_Position;" +
"attribute vec2 a_texCoord;" +
"varying vec2 v_texCoord;" +
"void main() {" +
" gl_Position = u_MVPMatrix * a_Position;" +
" v_texCoord = a_texCoord;" +
"}"
const val fragmentShader_Image = "precision mediump float;" +
"uniform sampler2D u_texture;" +
"varying vec2 v_texCoord;" +
"void main() {" +
" gl_FragColor = texture2D(u_texture, v_texCoord);" +
"}"
TextureLoader：（对象在Kotlin中基本上是静态的class如果你不熟悉的话）
object TextureLoader
{
var textures: Map<TextureName, Int> = mutableMapOf()
fun generateTextures(nameBitmapPair: List<Pair<TextureName, Bitmap>>, screenWidth: Int, screenHeight: Int)
{
val textureAmount = nameBitmapPair.size
val mutableTextureMap = mutableMapOf<TextureName, Int>()
if(textureAmount > 31 || textureAmount< 0)
{
throw IllegalStateException("Texture amount is bigger than 31 or smaller than 0. Texture limit for OPEN GL is 31, it can't be bigger than it")
}
val textureHandles = IntArray(textureAmount)
GLES20.glGenTextures(textureAmount, textureHandles, 0)
for (i in 0 until textureAmount)
{
if (textureHandles[i] != 0)
{
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR)
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR)
// Load the bitmap into the bound texture.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, nameBitmapPair.get(i).second, 0)
nameBitmapPair.get(i).second.recycle()
mutableTextureMap.put(nameBitmapPair.get(i).first, textureHandles[i])
Timber.i("created new texture, Name = ${nameBitmapPair.get(i).first}, ID = ${textureHandles[i]}")
}
else
{
throw RuntimeException("Error loading texture.")
}
}
textures = mutableTextureMap
}
}
Batcher：（处理 OpenGL 样板代码的 class 因此代码库的其余部分不会让任何人眼花缭乱）
class Batcher private constructor()
{
// Store the model matrix. This matrix is used to move models from object space (where each model can be thought
// of being located at the center of the universe) to world space.
private val mtrxModel = FloatArray(16)
// Allocate storage for the final combined matrix. This will be passed into the shader program.
private val mtrxMVP = FloatArray(16)
// Store the projection matrix. This is used to project the scene onto a 2D viewport.
private val mtrxProjection = FloatArray(16)
/* This was my UV array before I refactored the code to add animations. Now it's accessed by the
sprite.animator.getUvCoordinationForCurrentFrame()
private var uvArray = floatArrayOf(
0.0f, 0.0f,
0.0f, 0.20f,
0.20f, 0.20f,
0.20f, 0.0f)
*/
private var uvBuffer: FloatBuffer? = null
private var vertexBuffer: FloatBuffer? = null
private var indices = shortArrayOf(0, 1, 2, 0, 2, 3) // The order of vertexrendering.
private var indicesBuffer: ShortBuffer? = null
// NOTE: companion object is the static class of the Kotlin if you are not familiar with it. It's used to create a singleton here.
companion object
{
private var instance: Batcher? = null
fun getInstance(): Batcher
{
if (instance == null)
{
instance = Batcher()
}
return instance!!
}
}
//Constructor of the Kotlin classes if you aren't familiar with it
init
{
glEnable(GL_BLEND)
// initialize byte buffer for the draw list
indicesBuffer = ByteBuffer.allocateDirect(indices.size * 2)
.order(ByteOrder.nativeOrder())
.asShortBuffer()
indicesBuffer!!.put(indices)
.position(0)
val vertices = floatArrayOf(
0f, 0f, 0f,
0f, 1.0f, 0f,
1.0f, 1.0f, 0f,
1.0f, 0f, 0f)
// The vertex buffer.
vertexBuffer = ByteBuffer.allocateDirect(vertices.size * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
vertexBuffer!!.put(vertices)
.position(0)
}
fun render(sprites: Sprites)
{
//TODO should these be called on every draw call??
// Get handle to shape's transformation matrix
val u_MVPMatrix = glGetUniformLocation(ShaderHelper.programTexture, "u_MVPMatrix")
val a_Position = glGetAttribLocation(ShaderHelper.programTexture, "a_Position")
val a_texCoord = glGetAttribLocation(ShaderHelper.programTexture, "a_texCoord")
val u_texture = glGetUniformLocation(ShaderHelper.programTexture, "u_texture")
glEnableVertexAttribArray(a_Position)
glEnableVertexAttribArray(a_texCoord)
// "it" here is the currently iterated sprite object
sprites.forEach{
val uvArray = it.animator.getUvCoordinationForCurrentFrame()
if (uvArray != null)
{
updateUVBuffer(uvArray)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
// Matrix op - start
Matrix.setIdentityM(mtrxMVP, 0)
Matrix.setIdentityM(mtrxModel, 0)
Matrix.translateM(mtrxModel, 0, it.x.toFloat(), it.y.toFloat(), 0f)
Matrix.scaleM(mtrxModel, 0, it.scaledFrameWidth.toFloat(), it.scaledFrameHeight.toFloat(), 0f)
if (it.isHorizontallyFlipped)
{
Matrix.translateM(mtrxModel, 0, 1f, 0f, 0f)
Matrix.scaleM(mtrxModel, 0, -1f, 1f, 0f)
}
Matrix.multiplyMM(mtrxMVP, 0, mtrxModel, 0, mtrxMVP, 0)
Matrix.multiplyMM(mtrxMVP, 0, mtrxProjection, 0, mtrxMVP, 0)
// Matrix op - end
// Pass the data to shaders - start
// Prepare the triangle coordinate data
//Binds this vertex's data to a spot in the buffer
glVertexAttribPointer(a_Position, 3, GL_FLOAT, false, 0, vertexBuffer)
// Prepare the texture coordinates
glVertexAttribPointer(a_texCoord, 2, GL_FLOAT, false, 0, uvBuffer)
glUniformMatrix4fv(u_MVPMatrix, 1, false, mtrxMVP, 0)
// Set the sampler texture unit to where we have saved the texture.
// second param is the active texture index
glUniform1i(u_texture, TextureLoader.textures.get(it.textureName)!!)
// Draw the triangles
glDrawElements(GL_TRIANGLES, indices.size, GL_UNSIGNED_SHORT, indicesBuffer)
}
else
{
Timber.w("UV array of the sprite is null, skipping rendering. \nSprite: ${it}")
}
}
}
fun setScreenDimension(screenWidth: Int, screenHeight: Int)
{
Matrix.setIdentityM(mtrxProjection, 0)
Matrix.orthoM(mtrxProjection, 0, 0f, screenWidth.toFloat(), screenHeight.toFloat(), 0f, 0f, 1f)
}
private fun updateUVBuffer(uvArray: FloatArray)
{
uvBuffer = ByteBuffer.allocateDirect(uvArray.size * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer()
uvBuffer!!.put(uvArray)
.position(0)
}
要分配给纹理采样器统一的值不是纹理的对象编号。它必须是纹理绑定到的纹理单元。由于您的纹理绑定到纹理单元 0 (GL_TEXTURE0)，因此您需要将 0 分配给纹理采样器统一（默认为 0）：
glUniform1i(u_texture, TextureLoader.textures.get(it.textureName)!!)
glUniform1i(u_texture, 0)
glBindTexture binds a texture to the specified target and the current texture unit. The texture unit can be set by glActiveTexture.
如果你这样做
glActiveTexture(GLES20.GL_TEXTURE0)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
然后你必须将 0 分配给纹理采样器。但如果你这样做
glActiveTexture(GLES20.GL_TEXTURE1)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandles[i])
然后你必须将1分配给纹理采样器。
在绘制网格之前必须确保纹理已绑定。由于您有不同的纹理，因此每次要渲染具有纹理的几何体时都应调用 glBindTexture：例如：
glActiveTexture(GLES20.GL_TEXTURE0)
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, TextureLoader.textures.get(it.textureName)!!)
glUniform1i(u_texture, 0)
glDrawElements(GL_TRIANGLES, indices.size, GL_UNSIGNED_SHORT, indicesBuffer)