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commit f88ecdf4460ef265e632a6f65be1961c3a0ccd17
parent 8aec80e25dc2d5e2c759239e36e080ba54f3a09b
Author: Martin Kloeckner <mjkloeckner@gmail.com>
Date:   Thu,  1 Aug 2024 12:00:54 -0300

bind key to reload shaders

Diffstat:
M
opengl-example/main.c
 | 
30
+++++++++++++++++++++++++-----

1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/opengl-example/main.c b/opengl-example/main.c
@@ -136,6 +136,24 @@ bool new_program_from_shaders_source(GLuint *shader_program,
     return true;
 }
 
+GLuint current_program;
+
+bool reload_shaders(const char *vert_shader_file_path, const char *frag_shader_file_path) {
+    LOG_INFO("Reloading shaders");
+
+    GLuint new_program;
+    if(!new_program_from_shaders_source(&new_program,
+            vert_shader_file_path, frag_shader_file_path)) {
+
+        LOG_ERROR("Could not recompile shaders. Keeping previous version");
+        return false;
+    }
+    glDeleteProgram(current_program);
+    current_program = new_program;
+    LOG_INFO("Done reloading shaders");
+    return true;
+}
+
 // https://www.glfw.org/docs/3.3/group__keys.html
 static void key_handler(GLFWwindow *window,
         int key, int scancode, int action, int mods) {
@@ -146,13 +164,15 @@ static void key_handler(GLFWwindow *window,
             case GLFW_KEY_Q:
                 glfwSetWindowShouldClose(window, GLFW_TRUE);
                 break;
+            case GLFW_KEY_F5:
+                reload_shaders("main.vert", "main.frag");
+                break;
             default:
                 break;
         }
     }
 }
 
-
 bool setup_glfw(GLFWwindow **window) {
     glfwInit();
     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
@@ -182,7 +202,6 @@ bool setup_glfw(GLFWwindow **window) {
 }
 
 int main (void) {
-    GLuint shader_program;
     GLuint VBO, VAO; // Vertex Buffer Objects, Vertex Array Object
     GLFWwindow *window;
 
@@ -201,7 +220,7 @@ int main (void) {
     glGenVertexArrays(1, &VAO);
     glBindVertexArray(VAO);
 
-    if(!new_program_from_shaders_source(&shader_program, "main.vert", "main.frag")) {
+    if(!new_program_from_shaders_source(&current_program, "main.vert", "main.frag")) {
         glfwDestroyWindow(window);
         glfwTerminate();
         return -1;
@@ -209,11 +228,12 @@ int main (void) {
 
     glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(float), (void*)0);
     glEnableVertexAttribArray(0);
-    glUseProgram(shader_program);
 
     while(!glfwWindowShouldClose(window)) {
         glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT);
+
+        glUseProgram(current_program);
         glBindVertexArray(VAO);
         glDrawArrays(GL_TRIANGLES, 0, 3);
         glfwSwapBuffers(window);
@@ -221,7 +241,7 @@ int main (void) {
     }
 
     LOG_INFO("Freeing resources");
-    glDeleteProgram(shader_program);
+    glDeleteProgram(current_program);
     glfwDestroyWindow(window);
     glfwTerminate();
     return 0;