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OPENGL: Create new abstraction for GL texture objects.

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This commit is contained in:
Johannes Schickel 2016-01-02 02:15:20 +01:00
parent 5eb0ac0c9e
commit b081fe63e8
2 changed files with 223 additions and 90 deletions
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222
backends/graphics/opengl/texture.cpp
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@ -40,6 +40,127 @@ static GLuint nextHigher2(GLuint v) {
return ++v;
}
GLTexture::GLTexture(GLenum glIntFormat, GLenum glFormat, GLenum glType)
: _glIntFormat(glIntFormat), _glFormat(glFormat), _glType(glType),
_width(0), _height(0), _texCoords(), _glFilter(GL_NEAREST),
_glTexture(0) {
create();
}
GLTexture::~GLTexture() {
GL_CALL_SAFE(glDeleteTextures, (1, &_glTexture));
}
void GLTexture::enableLinearFiltering(bool enable) {
if (enable) {
_glFilter = GL_LINEAR;
} else {
_glFilter = GL_NEAREST;
}
bind();
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _glFilter));
}
void GLTexture::destroy() {
GL_CALL(glDeleteTextures(1, &_glTexture));
_glTexture = 0;
}
void GLTexture::create() {
// Release old texture name in case it exists.
destroy();
// Get a new texture name.
GL_CALL(glGenTextures(1, &_glTexture));
// Set up all texture parameters.
bind();
GL_CALL(glPixelStorei(GL_UNPACK_ALIGNMENT, 1));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
// If a size is specified, allocate memory for it.
if (_width != 0 && _height != 0) {
// Allocate storage for OpenGL texture.
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, _glIntFormat, _width, _height,
0, _glFormat, _glType, NULL));
}
}
void GLTexture::bind() {
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
}
void GLTexture::setSize(uint width, uint height) {
const uint oldWidth = _width;
const uint oldHeight = _height;
if (!g_context.NPOTSupported) {
_width = nextHigher2(width);
_height = nextHigher2(height);
} else {
_width = width;
_height = height;
}
// If a size is specified, allocate memory for it.
if (width != 0 && height != 0) {
const GLfloat texWidth = (GLfloat)width / _width;
const GLfloat texHeight = (GLfloat)height / _height;
_texCoords[0] = 0;
_texCoords[1] = 0;
_texCoords[2] = texWidth;
_texCoords[3] = 0;
_texCoords[4] = 0;
_texCoords[5] = texHeight;
_texCoords[6] = texWidth;
_texCoords[7] = texHeight;
// Allocate storage for OpenGL texture if necessary.
if (oldWidth != _width || oldHeight != _height) {
bind();
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, _glIntFormat, _width,
_height, 0, _glFormat, _glType, NULL));
}
}
}
void GLTexture::updateArea(const Common::Rect &area, const Graphics::Surface &src) {
// Set the texture on the active texture unit.
bind();
// Update the actual texture.
// Although we have the area of the texture buffer we want to update we
// cannot take advantage of the left/right boundries here because it is
// not possible to specify a pitch to glTexSubImage2D. To be precise, with
// plain OpenGL we could set GL_UNPACK_ROW_LENGTH to achieve this. However,
// OpenGL ES 1.0 does not support GL_UNPACK_ROW_LENGTH. Thus, we are left
// with the following options:
//
// 1) (As we do right now) Simply always update the whole texture lines of
// rect changed. This is simplest to implement. In case performance is
// really an issue we can think of switching to another method.
//
// 2) Copy the dirty rect to a temporary buffer and upload that by using
// glTexSubImage2D. This is what the Android backend does. It is more
// complicated though.
//
// 3) Use glTexSubImage2D per line changed. This is what the old OpenGL
// graphics manager did but it is much slower! Thus, we do not use it.
GL_CALL(glTexSubImage2D(GL_TEXTURE_2D, 0, 0, area.top, src.w, area.height(),
_glFormat, _glType, src.getBasePtr(0, area.top)));
}
GLint Texture::_maxTextureSize = 0;
void Texture::queryTextureInformation() {
@ -48,79 +169,42 @@ void Texture::queryTextureInformation() {
}
Texture::Texture(GLenum glIntFormat, GLenum glFormat, GLenum glType, const Graphics::PixelFormat &format)
: _glIntFormat(glIntFormat), _glFormat(glFormat), _glType(glType), _format(format), _glFilter(GL_NEAREST),
_glTexture(0), _textureData(), _userPixelData(), _allDirty(false) {
: _format(format), _glTexture(glIntFormat, glFormat, glType),
_textureData(), _userPixelData(), _allDirty(false) {
recreateInternalTexture();
}
Texture::~Texture() {
GL_CALL_SAFE(glDeleteTextures, (1, &_glTexture));
_textureData.free();
}
void Texture::releaseInternalTexture() {
GL_CALL(glDeleteTextures(1, &_glTexture));
_glTexture = 0;
_glTexture.destroy();
}
void Texture::recreateInternalTexture() {
// Release old texture name in case it exists.
releaseInternalTexture();
_glTexture.create();
// Get a new texture name.
GL_CALL(glGenTextures(1, &_glTexture));
// Set up all texture parameters.
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
GL_CALL(glPixelStorei(GL_UNPACK_ALIGNMENT, 1));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
// In case there is an actual texture setup we reinitialize it.
// In case image date exists assure it will be completely refreshed next
// time.
if (_textureData.getPixels()) {
// Allocate storage for OpenGL texture.
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, _glIntFormat, _textureData.w,
_textureData.h, 0, _glFormat, _glType, NULL));
// Mark dirts such that it will be completely refreshed the next time.
flagDirty();
}
}
void Texture::enableLinearFiltering(bool enable) {
if (enable) {
_glFilter = GL_LINEAR;
} else {
_glFilter = GL_NEAREST;
}
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _glFilter));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _glFilter));
_glTexture.enableLinearFiltering(enable);
}
void Texture::allocate(uint width, uint height) {
uint texWidth = width, texHeight = height;
if (!g_context.NPOTSupported) {
texWidth = nextHigher2(texWidth);
texHeight = nextHigher2(texHeight);
}
// Assure the texture can contain our user data.
_glTexture.setSize(width, height);
// In case the needed texture dimension changed we will reinitialize the
// texture.
if (texWidth != _textureData.w || texHeight != _textureData.h) {
// texture data buffer.
if (_glTexture.getWidth() != _textureData.w || _glTexture.getHeight() != _textureData.h) {
// Create a buffer for the texture data.
_textureData.create(texWidth, texHeight, _format);
// Set the texture.
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
// Allocate storage for OpenGL texture.
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, _glIntFormat, _textureData.w,
_textureData.h, 0, _glFormat, _glType, NULL));
_textureData.create(_glTexture.getWidth(), _glTexture.getHeight(), _format);
}
// Create a sub-buffer for raw access.
@ -175,17 +259,7 @@ void Texture::draw(GLfloat x, GLfloat y, GLfloat w, GLfloat h) {
updateTexture();
// Set the texture.
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
// Calculate the texture rect that will be drawn.
const GLfloat texWidth = (GLfloat)_userPixelData.w / _textureData.w;
const GLfloat texHeight = (GLfloat)_userPixelData.h / _textureData.h;
const GLfloat texcoords[4*2] = {
0, 0,
texWidth, 0,
0, texHeight,
texWidth, texHeight
};
_glTexture.bind();
// Calculate the screen rect where the texture will be drawn.
const GLfloat vertices[4*2] = {
@ -196,7 +270,7 @@ void Texture::draw(GLfloat x, GLfloat y, GLfloat w, GLfloat h) {
};
// Setup coordinates for drawing.
g_context.setDrawCoordinates(vertices, texcoords);
g_context.setDrawCoordinates(vertices, _glTexture.getTexCoords());
// Draw the texture to the screen buffer.
GL_CALL(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
@ -211,7 +285,7 @@ void Texture::updateTexture() {
// In case we use linear filtering we might need to duplicate the last
// pixel row/column to avoid glitches with filtering.
if (_glFilter == GL_LINEAR) {
if (_glTexture.isLinearFilteringEnabled()) {
if (dirtyArea.right == _userPixelData.w && _userPixelData.w != _textureData.w) {
uint height = dirtyArea.height();
@ -238,29 +312,7 @@ void Texture::updateTexture() {
}
}
// Set the texture.
GL_CALL(glBindTexture(GL_TEXTURE_2D, _glTexture));
// Update the actual texture.
// Although we keep track of the dirty part of the texture buffer we
// cannot take advantage of the left/right boundries here because it is
// not possible to specify a pitch to glTexSubImage2D. To be precise, with
// plain OpenGL we could set GL_UNPACK_ROW_LENGTH to achieve this. However,
// OpenGL ES 1.0 does not support GL_UNPACK_ROW_LENGTH. Thus, we are left
// with the following options:
//
// 1) (As we do right now) Simply always update the whole texture lines of
// rect changed. This is simplest to implement. In case performance is
// really an issue we can think of switching to another method.
//
// 2) Copy the dirty rect to a temporary buffer and upload that by using
// glTexSubImage2D. This is what the Android backend does. It is more
// complicated though.
//
// 3) Use glTexSubImage2D per line changed. This is what the old OpenGL
// graphics manager did but it is much slower! Thus, we do not use it.
GL_CALL(glTexSubImage2D(GL_TEXTURE_2D, 0, 0, dirtyArea.top, _textureData.w, dirtyArea.height(),
_glFormat, _glType, _textureData.getBasePtr(0, dirtyArea.top)));
_glTexture.updateArea(dirtyArea, _textureData);
// We should have handled everything, thus not dirty anymore.
clearDirty();