4 files changed, 68 insertions, 4 deletions

diff --git a/examples/triangle/ex_triangle.c b/examples/triangle/ex_triangle.c
index 5b6fbea..0191c18 100644
--- a/examples/triangle/ex_triangle.c
+++ b/examples/triangle/ex_triangle.c
@@ -35,8 +35,14 @@ int main() {
   gpu_renderpass_desc pass_description = {};
   gpu_renderpass* renderpass = gpu_renderpass_create(&pass_description);
 
-  str8 vert_path = str8lit("build/linux/x86_64/debug/triangle.vert.spv");
-  str8 frag_path = str8lit("build/linux/x86_64/debug/triangle.frag.spv");
+  str8 vert_path, frag_path;
+#ifdef CEL_REND_BACKEND_OPENGL
+  vert_path = str8lit("assets/shaders/triangle.vert");
+  frag_path = str8lit("assets/shaders/triangle.frag");
+#else
+  vert_path = str8lit("build/linux/x86_64/debug/triangle.vert.spv");
+  frag_path = str8lit("build/linux/x86_64/debug/triangle.frag.spv");
+#endif
   str8_opt vertex_shader = str8_from_file(&scratch, vert_path);
   str8_opt fragment_shader = str8_from_file(&scratch, frag_path);
   if (!vertex_shader.has_value || !fragment_shader.has_value) {
diff --git a/src/renderer/backends/opengl/backend_opengl.c b/src/renderer/backends/opengl/backend_opengl.c
index 529a0d9..8be1c2a 100644
--- a/src/renderer/backends/opengl/backend_opengl.c
+++ b/src/renderer/backends/opengl/backend_opengl.c
@@ -1,4 +1,6 @@
+#include <stddef.h>
 #include "colours.h"
+#include "opengl_helpers.h"
 #include "ral_types.h"
 #define CEL_REND_BACKEND_OPENGL
 #if defined(CEL_REND_BACKEND_OPENGL)
@@ -27,6 +29,8 @@ static opengl_context context;
 
 struct GLFWwindow;
 
+size_t vertex_attrib_size(vertex_attrib_type attr);
+
 bool gpu_backend_init(const char* window_name, struct GLFWwindow* window) {
   INFO("loading OpenGL backend");
 
@@ -69,6 +73,24 @@ gpu_pipeline* gpu_graphics_pipeline_create(struct graphics_pipeline_desc descrip
   u32 shader_id = shader_create_separate(description.vs.filepath.buf, description.fs.filepath.buf);
   pipeline->shader_id = shader_id;
 
+  // Vertex
+  u32 vao;
+  glGenVertexArrays(1, &vao);
+  pipeline->vao = vao;
+
+  // Attributes
+  u32 attr_count = description.vertex_desc.attributes_count;
+  printf("N attributes %d\n", attr_count);
+  u64 offset = 0;
+  size_t vertex_size = description.vertex_desc.stride;
+  for (u32 i = 0; i < description.vertex_desc.attributes_count; i++) {
+    opengl_vertex_attr format = format_from_vertex_attr(description.vertex_desc.attributes[i]);
+    glVertexAttribPointer(i, format.count, format.data_type, GL_FALSE, vertex_size, (void*)offset);
+    size_t this_offset = format.count * vertex_attrib_size(description.vertex_desc.attributes[i]);
+    printf("offset total %lld this attr %ld\n", offset, this_offset);
+    offset += this_offset;
+  }
+
   // Allocate uniform buffers if needed
   printf("data layouts %d\n", description.data_layouts_count);
   for (u32 layout_i = 0; layout_i < description.data_layouts_count; layout_i++) {
@@ -129,6 +151,7 @@ void copy_buffer_to_image_oneshot(buffer_handle src, texture_handle dst) {}
 void encode_bind_pipeline(gpu_cmd_encoder* encoder, pipeline_kind kind, gpu_pipeline* pipeline) {
   // In OpenGL this is more or less equivalent to just setting the shader
   glUseProgram(pipeline->shader_id);
+  glBindVertexArray(pipeline->vao);
 }
 void encode_bind_shader_data(gpu_cmd_encoder* encoder, u32 group, shader_data* data) {
   shader_data_layout sdl = data->shader_data_get_layout(data->data);
@@ -177,7 +200,7 @@ buffer_handle gpu_buffer_create(u64 size, gpu_buffer_type buf_type, gpu_buffer_f
   buffer->size = size;
 
   if (data) {
-    TRACE("Upload data as part of buffer creation");
+    TRACE("Upload data (%d bytes) as part of buffer creation", size);
     glBufferData(gl_buf_type, buffer->size, data, GL_STATIC_DRAW);
   }
 
diff --git a/src/renderer/backends/opengl/backend_opengl.h b/src/renderer/backends/opengl/backend_opengl.h
index 876cfe4..a9835c1 100644
--- a/src/renderer/backends/opengl/backend_opengl.h
+++ b/src/renderer/backends/opengl/backend_opengl.h
@@ -15,7 +15,7 @@ typedef struct gpu_pipeline_layout {
 } gpu_pipeline_layout;
 typedef struct gpu_pipeline {
   u32 shader_id;
-  u32 pad;
+  u32 vao;
 } gpu_pipeline;
 typedef struct gpu_renderpass {
   void *pad
diff --git a/src/renderer/backends/opengl/opengl_helpers.h b/src/renderer/backends/opengl/opengl_helpers.h
index 6f70f09..2f6bef3 100644
--- a/src/renderer/backends/opengl/opengl_helpers.h
+++ b/src/renderer/backends/opengl/opengl_helpers.h
@@ -1 +1,36 @@
 #pragma once
+#include "ral_types.h"
+#include <glad/glad.h>
+#include <glfw3.h>
+typedef struct opengl_vertex_attr {
+  u32 count;
+  GLenum data_type;
+} opengl_vertex_attr ;
+opengl_vertex_attr format_from_vertex_attr(vertex_attrib_type attr) {
+  switch (attr) {
+    case ATTR_F32:
+      return (opengl_vertex_attr){.count = 1, .data_type = GL_FLOAT };
+    case ATTR_U32:
+      return (opengl_vertex_attr){.count = 1, .data_type = GL_UNSIGNED_INT };
+    case ATTR_I32:
+      return (opengl_vertex_attr){.count = 1, .data_type = GL_INT };
+    case ATTR_F32x2:
+      return (opengl_vertex_attr){.count = 2, .data_type = GL_FLOAT };
+    case ATTR_U32x2:
+      // return VK_FORMAT_R32G32_UINT;
+    case ATTR_I32x2:
+      // return VK_FORMAT_R32G32_UINT;
+    case ATTR_F32x3:
+      return (opengl_vertex_attr){.count = 3, .data_type = GL_FLOAT };
+    case ATTR_U32x3:
+      // return VK_FORMAT_R32G32B32_UINT;
+    case ATTR_I32x3:
+      // return VK_FORMAT_R32G32B32_SINT;
+    case ATTR_F32x4:
+      return (opengl_vertex_attr){.count = 4, .data_type = GL_FLOAT };
+    case ATTR_U32x4:
+      // return VK_FORMAT_R32G32B32A32_UINT;
+    case ATTR_I32x4:
+      // return VK_FORMAT_R32G32B32A32_SINT;
+  }
+}
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