srender: added API to render custom meshes.

src/srender.h

@@ -6,25 +6,45 @@ extern "C" {
 #endif
 
 #include <stdbool.h>
+#include <stdio.h>
 
 #include "vectorial/simd4x4f.h"
 
 typedef struct srndr srndr;
 typedef struct srview srview;
 typedef struct srcmdbuf srcmdbuf;
+typedef union srvrtxdata srvrtxdata;
+typedef struct srmeshdata srmeshdata;
+extern GLuint* srDefaultVAId;
 
 typedef enum {
   SRndrCmdTypeFrame = 0,
   SRndrCmdTypeGrid,
   SRndrCmdTypeCube,
   SRndrCmdTypeSphere,
-  SrndrCmdTypePoint,
+  SrndrCmdTypeMesh,
 } SRndrCmdType;
 
+//
+// Simple Mesh Data
+//
+typedef struct srmeshdata {
+  int nvertices;
+  int nindices;
+
+  GLuint vao_id;
+  GLuint vb_id;
+  GLuint idb_id;
+
+  GLuint count;
+  GLenum mode;
+} srmeshdata;
+
 typedef struct srcmd {
   simd4x4f mat;
   simd4f color;
   SRndrCmdType type;
+  srmeshdata* meshdata;
 } srcmd;
 
 //
@@ -56,6 +76,112 @@ srcmd* srcmd_create(srcmdbuf* cmdbuf);
 
 void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf);
 
+//
+// Vertex Data
+//
+typedef union srvrtxdata {
+  struct {
+    float x, y, z, w;
+    float nx, ny, nz;
+    float s, t;
+    GLubyte r, g, b, a;
+  };
+  struct {
+    float pos[4];
+    float n[3];
+    float uv[2];
+    GLubyte color[4];
+  };
+} srvrtxdata;
+
+inline srmeshdata* srmesh_create(
+    srvrtxdata* vrtxdata,
+    int nvertices,
+    GLuint* idxdata,
+    int nindices,
+    GLenum prim_mode,
+    GLuint count) {
+  srmeshdata* result = (srmeshdata*)calloc(sizeof(srmeshdata), 1);
+
+  result->nvertices = nvertices;
+  result->nindices = nindices;
+  result->mode = prim_mode;
+  result->count = count;
+
+  glGenVertexArrays(1, &result->vao_id);
+  glBindVertexArray(result->vao_id);
+
+  glGenBuffers(1, &result->vb_id);
+  glBindBuffer(GL_ARRAY_BUFFER, result->vb_id);
+
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(
+      0,
+      4,
+      GL_FLOAT,
+      GL_FALSE,
+      (sizeof(srvrtxdata)),
+      (void*)0);
+
+  glEnableVertexAttribArray(1);
+  glVertexAttribPointer(
+      1,
+      3,
+      GL_FLOAT,
+      GL_FALSE,
+      (sizeof(srvrtxdata)),
+      (void*)(sizeof(float) * 4));
+
+  // Attribute 2: texture coordinates
+  glEnableVertexAttribArray(2);
+  glVertexAttribPointer(
+      2,
+      2,
+      GL_FLOAT,
+      GL_FALSE,
+      (sizeof(srvrtxdata)),
+      (void*)(sizeof(float) * 7));
+
+  // Attribute 3: color
+  glEnableVertexAttribArray(3);
+  glVertexAttribPointer(
+      3,
+      4,
+      GL_UNSIGNED_BYTE,
+      GL_TRUE,
+      (sizeof(srvrtxdata)),
+      (void*)(sizeof(float) * 9));
+
+  glBufferData(
+      GL_ARRAY_BUFFER,
+      sizeof(srvrtxdata) * nvertices,
+      vrtxdata,
+      GL_DYNAMIC_DRAW);
+
+  glGenBuffers(1, &result->idb_id);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, result->idb_id);
+  for (int i = 0; i < nindices; i++) {
+    printf ("idx %2d: %d\n", i, idxdata[i]);
+  }
+  glBufferData(
+      GL_ELEMENT_ARRAY_BUFFER,
+      sizeof(GLuint) * nindices,
+      idxdata,
+      GL_STATIC_DRAW);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+  glBindVertexArray(0);
+
+  return result;
+}
+
+inline void srmesh_destroy(srmeshdata* mesh) {
+  glDeleteVertexArrays(1, &mesh->vao_id);
+  glDeleteBuffers(1, &mesh->vb_id);
+  glDeleteBuffers(1, &mesh->idb_id);
+  free(mesh);
+}
+
 //
 // srender Implementation
 //
@@ -94,45 +220,12 @@ typedef struct srcmdbuf {
   srcmd* cmds;
 } srcmdbuf;
 
-//
-// Vertex Data
-//
-typedef union srvrtxdata {
-  struct {
-    float x, y, z, w;
-    float nx, ny, nz;
-    float s, t;
-    GLubyte r, g, b, a;
-  };
-  struct {
-    float pos[4];
-    float n[4];
-    float uv[2];
-    GLubyte color[4];
-  };
-} srvrtxdata;
-
 //
 // Vertex Buffer Object for all debug objects (coord frame, grid, cube, ...)
 //
 const GLint DEBUG_VBO_SIZE = 1024;
-GLuint gDebugShapesVBOId = 0;
 GLuint gDebugShapesVAId = 0;
-
-//
-// Simple Mesh Data
-//
-typedef struct srmeshdata {
-  int nvertices;
-  int nindices;
-
-  GLuint vao_id;
-  GLuint vb_id;
-  GLuint idb_id;
-
-  GLuint count;
-  GLenum mode;
-} srmeshdata;
+GLuint gDebugShapesVBOId = 0;
 
 static srmeshdata gCoordFrameMesh = {0};
 static srmeshdata gGridMesh = {0};
@@ -422,7 +515,7 @@ void init_debug_meshes() {
   glBufferSubData(
       GL_ARRAY_BUFFER,
       dbg_vbuf_offset,
-      sizeof(srvrtxdata) * 44,
+      sizeof(union srvrtxdata) * 44,
       grid_vertices);
   dbg_vbuf_offset += sizeof(srvrtxdata) * 44;
 
@@ -494,9 +587,9 @@ void init_debug_meshes() {
   glBufferSubData(
       GL_ARRAY_BUFFER,
       dbg_vbuf_offset,
-      sizeof(srvrtxdata) * 24,
+      sizeof(srvrtxdata) * gCubeMesh.nvertices,
       cube_vertices);
-  dbg_vbuf_offset += sizeof(srvrtxdata) * 24;
+  dbg_vbuf_offset += sizeof(srvrtxdata) * gCubeMesh.nvertices;
 
   GLuint cube_indices[] = {
       // clang-format off
@@ -624,8 +717,6 @@ void init_debug_meshes() {
   gUVSphereMesh.count = gUVSphereMesh.nindices;
 
   glBindVertexArray(0);
-
-  gLog ("Debug Mesh Vertices: %d", dbg_vbuf_offset / sizeof(union srvrtxdata));
 };
 
 //
@@ -807,6 +898,22 @@ void srndr_run_sphere_command(const srcmd* cmd) {
   glBindVertexArray(0);
 }
 
+void srndr_run_mesh_command(const srcmd* cmd) {
+  glBindVertexArray(cmd->meshdata->vao_id);
+
+  glBindBuffer(GL_ARRAY_BUFFER, cmd->meshdata->vb_id);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cmd->meshdata->idb_id);
+  glDrawElements(
+      cmd->meshdata->mode,
+      cmd->meshdata->count,
+      GL_UNSIGNED_INT,
+      (void*)0);
+
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+  glBindVertexArray(0);
+}
+
 void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf) {
   glBindFramebuffer(GL_DRAW_FRAMEBUFFER, sview->mFrameBufferId);
 
@@ -851,6 +958,9 @@ void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf) {
       case SRndrCmdTypeSphere:
         srndr_run_sphere_command(cmd);
         break;
+      case SrndrCmdTypeMesh:
+        srndr_run_mesh_command(cmd);
+        break;
       default:
         gLog("Invalid command type %d at index %d", cmd->type, i);
         break;