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2025-07-14 11:34:38 +08:00

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/*
* Copyright 2014 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "tango-gl/texture.h"
#include "tango-gl/util.h"
namespace tango_gl {
static const int kMaxExponentiation = 12;
static int RoundUpPowerOfTwo(int w) {
int start = 2;
for (int i = 0; i <= kMaxExponentiation; ++i) {
if (w < start) {
w = start;
break;
} else {
start = start << 1;
}
}
return w;
}
Texture::Texture(const char* file_path) {
#ifdef __ANDROID__
if (!LoadFromPNG(file_path)) {
LOGE("Texture initialing error");
}
#endif
}
#ifdef __ANDROID__
bool Texture::LoadFromPNG(const char* file_path) {
FILE* file = fopen(file_path, "rb");
if (file == NULL) {
LOGE("fp not loaded: %s", strerror(errno));
return false;
}
fseek(file, 8, SEEK_CUR);
png_structp png_ptr =
png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
png_infop info_ptr = png_create_info_struct(png_ptr);
png_init_io(png_ptr, file);
png_set_sig_bytes(png_ptr, 8);
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width_, &height_, &bit_depth_, &color_type_,
NULL, NULL, NULL);
width_ = RoundUpPowerOfTwo(width_);
height_ = RoundUpPowerOfTwo(height_);
int row = width_ * (color_type_ == PNG_COLOR_TYPE_RGBA ? 4 : 3);
byte_data_ = new char[row * height_];
png_bytep* row_pointers = new png_bytep[height_];
for (uint i = 0; i < height_; ++i) {
row_pointers[i] = (png_bytep)(byte_data_ + i * row);
}
png_read_image(png_ptr, row_pointers);
png_destroy_read_struct(&png_ptr, &info_ptr, 0);
glGenTextures(1, &texture_id_);
glBindTexture(GL_TEXTURE_2D, texture_id_);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
util::CheckGlError("glBindTexture");
if (color_type_ == PNG_COLOR_TYPE_RGBA) {
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width_, height_, 0, GL_RGBA,
GL_UNSIGNED_BYTE, byte_data_);
} else {
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width_, height_, 0, GL_RGB,
GL_UNSIGNED_BYTE, byte_data_);
}
util::CheckGlError("glTexImage2D");
glBindTexture(GL_TEXTURE_2D, 0);
fclose(file);
delete[] row_pointers;
delete[] byte_data_;
return true;
}
#endif
GLuint Texture::GetTextureID() const { return texture_id_; }
Texture::~Texture() {
if (byte_data_ != NULL) {
delete[] byte_data_;
}
byte_data_ = NULL;
}
} // namespace tango_gl