primer commit

src/main.cpp

@@ -0,0 +1,219 @@
+// src/main.cpp
+#include <iostream>
+#include <string>
+#include <SDL3/SDL.h>
+#include <glad/glad.h>
+
+// Vertex shader: genera posiciones de pantalla y una coordenada uv en [0,1]
+static const char *vertexShaderSrc = R"glsl(
+#version 330 core
+layout(location = 0) in vec2 aPos;
+out vec2 vUV;
+void main() {
+    vUV = aPos * 0.5 + 0.5;
+    gl_Position = vec4(aPos, 0.0, 1.0);
+}
+)glsl";
+
+// Fragment shader: adapta tu shader de Shadertoy
+static const char *fragmentShaderSrc = R"glsl(
+#version 330 core
+out vec4 FragColor;
+in vec2 vUV;
+uniform vec2 iResolution;
+uniform float iTime;
+
+vec3 palette( float t) {
+    vec3 a = vec3(1.0, 0.5, 0.5);
+    vec3 b = vec3(1.0, 0.5, 0.5);
+    vec3 c = vec3(1.0, 1.0, 1.0);
+    vec3 d = vec3(0.263, 0.416, 0.557);
+    return a + b * cos( 6.28318 * (c * t * d) );
+}
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+    vec2 uv = (fragCoord * 2.0 - iResolution.xy) / iResolution.y;
+    float d = length(uv);
+    vec3 col = palette(d);
+    d = sin(d * 8.0 + iTime) / 8.0;
+    d = abs(d);
+    d = 0.02 / d;
+    col *= d;
+    fragColor = vec4(col, 1.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}
+)glsl";
+
+// helpers
+static GLuint compileShader(GLenum type, const char *src)
+{
+    GLuint s = glCreateShader(type);
+    glShaderSource(s, 1, &src, nullptr);
+    glCompileShader(s);
+    GLint ok = 0;
+    glGetShaderiv(s, GL_COMPILE_STATUS, &ok);
+    if (!ok)
+    {
+        GLint len = 0;
+        glGetShaderiv(s, GL_INFO_LOG_LENGTH, &len);
+        std::string log(len, ' ');
+        glGetShaderInfoLog(s, len, nullptr, &log[0]);
+        std::cerr << "Shader compile error: " << log << '\n';
+        glDeleteShader(s);
+        return 0;
+    }
+    return s;
+}
+
+static GLuint linkProgram(GLuint vs, GLuint fs)
+{
+    GLuint p = glCreateProgram();
+    glAttachShader(p, vs);
+    glAttachShader(p, fs);
+    glLinkProgram(p);
+    GLint ok = 0;
+    glGetProgramiv(p, GL_LINK_STATUS, &ok);
+    if (!ok)
+    {
+        GLint len = 0;
+        glGetProgramiv(p, GL_INFO_LOG_LENGTH, &len);
+        std::string log(len, ' ');
+        glGetProgramInfoLog(p, len, nullptr, &log[0]);
+        std::cerr << "Program link error: " << log << '\n';
+        glDeleteProgram(p);
+        return 0;
+    }
+    return p;
+}
+
+int main(int argc, char **argv)
+{
+    if (!SDL_Init(SDL_INIT_VIDEO))
+    {
+        std::cerr << "SDL_Init error: " << SDL_GetError() << '\n';
+        return -1;
+    }
+
+    // Pedir contexto OpenGL 3.3 Core
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+
+    int winW = 800, winH = 800;
+    // SDL3: SDL_CreateWindow signature es (title, w, h, flags)
+    SDL_Window *window = SDL_CreateWindow("Shadertoy SDL3 + OpenGL",
+                                          winW, winH,
+                                          SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
+    if (!window)
+    {
+        std::cerr << "SDL_CreateWindow error: " << SDL_GetError() << '\n';
+        SDL_Quit();
+        return -1;
+    }
+
+    SDL_GLContext glContext = SDL_GL_CreateContext(window);
+    if (!glContext)
+    {
+        std::cerr << "SDL_GL_CreateContext error: " << SDL_GetError() << '\n';
+        SDL_DestroyWindow(window);
+        SDL_Quit();
+        return -1;
+    }
+
+    if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress))
+    {
+        std::cerr << "Failed to initialize GL loader\n";
+        SDL_GL_DestroyContext(glContext);
+        SDL_DestroyWindow(window);
+        SDL_Quit();
+        return -1;
+    }
+
+    GLuint vs = compileShader(GL_VERTEX_SHADER, vertexShaderSrc);
+    GLuint fs = compileShader(GL_FRAGMENT_SHADER, fragmentShaderSrc);
+    if (!vs || !fs)
+        return -1;
+    GLuint program = linkProgram(vs, fs);
+    glDeleteShader(vs);
+    glDeleteShader(fs);
+    if (!program)
+        return -1;
+
+    float quadVertices[] = {
+        -1.0f,
+        -1.0f,
+        1.0f,
+        -1.0f,
+        -1.0f,
+        1.0f,
+        1.0f,
+        1.0f,
+    };
+
+    GLuint vao = 0, vbo = 0;
+    glGenVertexArrays(1, &vao);
+    glGenBuffers(1, &vbo);
+    glBindVertexArray(vao);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), quadVertices, GL_STATIC_DRAW);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void *)0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
+
+    GLint locRes = glGetUniformLocation(program, "iResolution");
+    GLint locTime = glGetUniformLocation(program, "iTime");
+
+    bool running = true;
+    Uint32 startTicks = SDL_GetTicks();
+
+    while (running)
+    {
+        SDL_Event e;
+        while (SDL_PollEvent(&e))
+        {
+            if (e.type == SDL_EVENT_QUIT)
+                running = false;
+            if (e.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED)
+                running = false;
+        }
+
+        int w, h;
+        SDL_GetWindowSize(window, &w, &h);
+        glViewport(0, 0, w, h);
+        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT);
+
+        glUseProgram(program);
+        if (locRes >= 0)
+            glUniform2f(locRes, float(w), float(h));
+        if (locTime >= 0)
+        {
+            float t = (SDL_GetTicks() - startTicks) / 1000.0f;
+            glUniform1f(locTime, t);
+        }
+
+        glBindVertexArray(vao);
+        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+        glBindVertexArray(0);
+
+        SDL_GL_SwapWindow(window);
+        SDL_Delay(1);
+    }
+
+    glDeleteBuffers(1, &vbo);
+    glDeleteVertexArrays(1, &vao);
+    glDeleteProgram(program);
+
+    SDL_GL_DestroyContext(glContext);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+    return 0;
+}