Mercurial > hg > ascension / file diff

--- a/src/mesh.c	Sat May 10 15:42:56 2025 +0200
+++ b/src/mesh.c	Sat May 10 18:51:45 2025 +0200
@@ -44,6 +44,7 @@
 }
 
 void asc_mesh_free_buffers(AscMesh *mesh, unsigned count) {
+    if (count == 1 && mesh->vbo == 0) return; // hack to skip this function until we remove it
     asc_dprintf("Free mesh buffers for %u meshes.", count);
     GLuint buffers[count];
     GLuint arrays[count];
@@ -60,11 +61,52 @@
     asc_error_catch_all_gl();
 }
 
-void asc_mesh_draw_triangle_strip(AscMesh *mesh) {
+void asc_mesh_draw_triangle_strip(const AscMesh *mesh) {
     glBindVertexArray(mesh->vao);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, mesh->vertices);
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, mesh->vtx_count);
 #ifndef NDEBUG
     // only unbind in debug mode to detect accidental re-use of the wrong VAO
     glBindVertexArray(0);
 #endif
 }
+
+void asc_mesh_destroy(AscMesh *mesh) {
+    asc_mesh_free_buffers(mesh, 1);
+    free(mesh->vtx_data);
+}
+
+void asc_mesh_plane_2d(AscMesh *mesh) {
+    if (mesh->vbo == 0) {
+        asc_mesh_allocate_buffers(mesh, 1);
+    }
+    free(mesh->vtx_data);
+    asc_dprintf("Create plane in VBO %u and VAO %u", mesh->vbo, mesh->vao);
+    mesh->vtx_count = 4;
+    AscMeshVertex2d data[4] = {
+        {
+            .pos = {{0.0f, 0.0f}},
+            .uv = {{0.0f, 0.0f}},
+        } , // bottom left
+        {
+            .pos = {{0.0f, 1.0f}},
+            .uv = {{0.0f, 1.0f}},
+        }, // top left
+        {
+            .pos = {{1.0f, 0.0f}},
+            .uv = {{1.0f, 0.0f}},
+        }, // bottom right
+        {
+            .pos = {{1.0f, 1.0f}},
+            .uv = {{1.0f, 1.0f}},
+        } // top right
+    };
+    mesh->vtx_data = malloc(sizeof(data));
+    memcpy(mesh->vtx_data, data, sizeof(data));
+    glBindBuffer(GL_ARRAY_BUFFER, mesh->vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(data), mesh->vtx_data, GL_STATIC_DRAW);
+    glBindVertexArray(mesh->vao);
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(AscMeshVertex2d), (void*)offsetof(AscMeshVertex2d, pos));
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(AscMeshVertex2d), (void*)offsetof(AscMeshVertex2d, uv));
+    glEnableVertexAttribArray(1);
+}