feat: add model matrix transformation hierarchy and delta time tracking

src/engine/renderer/shaders/shader.c

@@ -64,9 +64,9 @@ Shader shader_create(const char *vertexFile, const char *fragmentFile) {
     char *vertexSource = get_file_contents(vertexFile);
     char *fragmentSource = get_file_contents(fragmentFile);
 
-    if (!vertexSource || !fragmentSource) {
+    if (vertexSource == NULL || fragmentSource == NULL) {
         log_error("Failed to load shader files. Returning empty shader\n");
-        Shader emptyShader = { .ID = 0};
+        Shader emptyShader = { .ID = 0, .camMatrixLocation = -1};
         if (vertexSource)
             free(vertexSource);
         if (fragmentSource)
@@ -101,7 +101,19 @@ Shader shader_create(const char *vertexFile, const char *fragmentFile) {
     glDeleteShader(vertexShader);
     glDeleteShader(fragmentShader);
 
-    Shader newShader = { .ID = programID };
+    GLint camMatrixLocation = glGetUniformLocation(programID, "camMatrix");
+    if (camMatrixLocation == -1) {
+        log_error("Uniform 'camMatrix' not found after linking shader program %u. Is it used in default.vert?", programID);
+    }
+
+    GLint modelMatrixLocation = glGetUniformLocation(programID, "modelMatrix");
+    if (modelMatrixLocation == -1) {
+        log_warn("Uniform 'modelMatrix' not found in shader program %u. Is it used in default.vert?", programID);
+    }
+
+    Shader newShader = {    .ID = programID,
+                            .camMatrixLocation = camMatrixLocation,
+                            .modelMatrixLocation = modelMatrixLocation };
     return newShader;
 }
 

src/engine/renderer/shaders/shader.h

@@ -11,6 +11,9 @@
 typedef struct {
     // Reference ID of the shader program
     GLuint ID;
+    // Location of the camera matrix uniform, set at creation
+    GLint camMatrixLocation;
+    GLint modelMatrixLocation;
 } Shader;
 
 char *get_file_contents(const char *filename);