Add the textrender function

This commit is contained in:
2025-12-09 22:46:37 +08:00
parent 7067214c34
commit f6268951b7
4 changed files with 140 additions and 0 deletions

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@@ -8,7 +8,10 @@ FontManager::~FontManager() {
for (auto& pair : m_fonts) {
TTF_CloseFont(pair.second);
}
m_fonts.clear();
}
TTF_Font* FontManager::loadFont(const std::string& fontID, int ptSize) {
@@ -33,3 +36,5 @@ TTF_Font* FontManager::getFont(const std::string& key) {
return (it != m_fonts.end()) ? it->second : nullptr;
}

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@@ -1,6 +1,7 @@
#pragma once
#include <string>
#include <unordered_map>
#include <SDL3/SDL.h>
#include <SDL3_ttf/SDL_ttf.h>
class FontManager {
@@ -14,7 +15,12 @@ public:
// 获取已加载的字体
TTF_Font* getFont(const std::string& key);
private:
// 用哈希表存储字体
std::unordered_map<std::string, TTF_Font*> m_fonts;
};

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@@ -0,0 +1,87 @@
#include "TextRenderer.h"
TextRenderer::TextRenderer(FontManager& fontManager,SDL_Renderer* renderer) :
m_fontManager(fontManager),
m_renderer(renderer)
{
}
TextRenderer::~TextRenderer() {
for (auto& pair : m_cache) {
SDL_DestroyTexture(pair.second.texture);
}
m_cache.clear();
}
void TextRenderer::renderText(const std::string& text, const std::string& fontID, int x, int y, SDL_Color color) {
std::string key = makeCacheKey(text, fontID, color);
auto it = m_cache.find(key);
// 查找缓存
if (it != m_cache.end()) {
// 使用缓存的纹理, SDL_FRect为浮点数矩形
SDL_FRect dest = { static_cast<float>(x), static_cast<float>(y),
static_cast<float>(it->second.width),
static_cast<float>(it->second.height) };
// 绘制材质 NULL 的含义:绘制整个纹理(从 (0,0) 到纹理的完整宽高) &dest 目标区域
SDL_RenderTexture(m_renderer, it->second.texture, NULL, &dest);
return;
}
// 创建新的纹理
TTF_Font* font = m_fontManager.getFont(fontID);
if (!font) {
SDL_Log("错误:字体未找到 %s\n", fontID.c_str());
return;
}
// 创建文字表面
SDL_Surface* surface = TTF_RenderText_Solid(font, text.c_str(),text.length(), color);
if (!surface) {
printf("错误:无法创建文字表面\n");
return;
}
// 创建纹理
SDL_Texture* texture = SDL_CreateTextureFromSurface(m_renderer, surface);
if (!texture) {
SDL_Log("错误:无法创建纹理\n");
SDL_DestroySurface(surface);
return;
}
// 保存到缓存
CachedText cached;
cached.texture = texture;
cached.width = surface->w;
cached.height = surface->h;
m_cache[key] = cached;
// 渲染
SDL_FRect dest = { static_cast<float>(x), static_cast<float>(y),
static_cast<float>(surface->w),
static_cast<float>(surface->h) };
SDL_RenderTexture(m_renderer, texture, NULL, &dest);
// 清理表面
SDL_DestroySurface(surface);
}
SDL_Texture* TextRenderer::createTextTexture(const std::string& text, const std::string& fontID, SDL_Color color) {
}
std::string makeCacheKey(const std::string& text, const std::string& fontID, SDL_Color color) {
return text + "|" + fontID + "|" +
std::to_string(color.r) + "-" +
std::to_string(color.g) + "-" +
std::to_string(color.b) + "-" +
std::to_string(color.a);
}

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@@ -0,0 +1,42 @@
#pragma once
#include <string>
#include <unordered_map>
#include <SDL3/SDL.h>
#include <SDL3_ttf/SDL_ttf.h>
#include "FontManager.h"
class TextRenderer {
private:
SDL_Renderer* m_renderer;
FontManager& m_fontManager;
// 缓存文字纹理
struct CachedText {
SDL_Texture* texture;
int width;
int height;
};
std::unordered_map<std::string, CachedText> m_cache;
// 创建材质
SDL_Texture* createTextTexture(const std::string& text, const std::string& fontID, SDL_Color color);
// 创建一个唯一的缓存键:文本 + 字体 + 颜色
std::string makeCacheKey(const std::string& text, const std::string& fontID, SDL_Color color);
public:
TextRenderer(FontManager& fontManager, SDL_Renderer* renderer);
~TextRenderer();
//渲染文本
void renderText(const std::string& text, const std::string& fontID, int x, int y, SDL_Color color);
};