57 lines
1.2 KiB
C++
57 lines
1.2 KiB
C++
#define STB_IMAGE_IMPLEMENTATION
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#include"stb_image.h"
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#include "image.h"
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Image::Image(const int& width, const int& height, RGBA* data) {
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m_width = width;
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m_height = height;
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if (data) {
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m_data = new RGBA[m_width * m_height];
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memcpy(m_data, data, sizeof(RGBA) * m_width * m_height);
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}
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}
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Image::~Image() {
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if (m_data != nullptr) {
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delete[] m_data;
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}
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}
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//仅接收（-1，1）的参数
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RGBA Image::GetColor(const float& p_u, const float& p_v)
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{
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if (!m_data) { return RGBA(255,255,255,255); }
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/*此处注意截断误差，不要直接算index，一定要让x和y分别截断一下*/
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int x = fmod(p_u + 1, 1.f) * m_width;
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int y = fmod(p_v + 1, 1.f) * m_height;
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return m_data[x + y * m_width];
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}
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Image* Image::CreateImage(const std::string& path) {
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int picType = 0;
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int width{ 0 }, height{ 0 };
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stbi_set_flip_vertically_on_load(true);
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unsigned char* bits = stbi_load(path.c_str(), &width, &height, &picType, STBI_rgb_alpha);
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for (int i = 0; i < width * height * 4; i += 4)
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{
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BYTE tmp = bits[i];
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bits[i] = bits[i + 2];
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bits[i + 2] = tmp;
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}
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Image* image = new Image(width, height, (RGBA*)bits);
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stbi_image_free(bits);
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return image;
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}
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void Image::DestroyImage(Image* image) {
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if (image) {
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delete image;
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}
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}
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