Started working on default rendering shader.

data/shaders/default_frag.glsl

@@ -0,0 +1,9 @@
+#version 330
+
+out vec4 fragColor;
+smooth in vec4 ioFragColor;
+
+void main()
+{
+    fragColor = vec4(1.0, 0.0, 0.0, 1.0);
+}

data/shaders/default_vert.glsl

@@ -0,0 +1,19 @@
+#version 330
+
+in vec4 inCoord;
+in vec3 inNormal;
+in vec2 inUV;
+in vec4 inColor;
+
+uniform mat4 uModelMatrix;
+uniform mat4 uViewMatrix;
+uniform mat4 uProjectionMatrix;
+
+smooth out vec4 ioFragColor;
+
+void main()
+{
+    ioFragColor = inColor;
+    gl_Position = (uProjectionMatrix * uViewMatrix * uModelMatrix * inCoord);
+
+}

src/srender.c

@@ -20,73 +20,222 @@ typedef struct srview {
   GLuint mColorTexture;
   GLuint mDepthTexture;
 
-	simd4x4f proj;
+  simd4x4f proj;
-	simd4x4f view;
+  simd4x4f view;
 } srview;
 
 typedef struct srcmdbuf {
-	int ncmds;
+  int ncmds;
-	int idx;
+  int idx;
-	srcmd* cmds;
+  srcmd* cmds;
 } srcmdbuf;
 
 //
 // Vertex Data
 //
 typedef union srvrtxdata {
-	struct {
+  struct {
-		float x, y, z, w;
+    float x, y, z, w;
-		float nx, ny, nz;
+    float nx, ny, nz;
-		float s, t;
+    float s, t;
-		GLubyte r,g,b,a;
+    GLubyte r, g, b, a;
-	};
+  };
-	struct {
+  struct {
-		float pos[4];
+    float pos[4];
-		float n[4];
+    float n[4];
-		float uv[2];
+    float uv[2];
-		GLubyte color[4];
+    GLubyte color[4];
-	};
+  };
 } srvrtxdata;
 
 //
 // Simple Mesh Data
 //
 typedef struct srmeshdata {
-	int nvertices;
+  int nvertices;
-	int nindices;
+  int nindices;
 
-	srvrtxdata *vertices;
+  GLuint vertex_buffer_id;
-	int *indices;
+  GLuint index_buffer_id;
 } srmeshdata;
 
 static srmeshdata gCoordFrameMesh = {0};
 
-void init_debug_meshes () {
+typedef struct srshader {
-	assert (gCoordFrameMesh.nvertices == 0);
+  const char* vert_fname;
+  const char* frag_fname;
 
-	gCoordFrameMesh.nvertices = 6;
+  GLuint program_id;
+  GLuint vert_shader_id;
+  GLuint frag_shader_id;
+} srshader;
 
-	srvrtxdata coord_frame_vertices[] = {
+static srshader gDefaultShader = {"default_vert.glsl", "default_frag.glsl", 0, 0, 0};
-		{0.0f, 0.0f, 0.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	255, 0, 0, 255  },
-		{1.0f, 0.0f, 0.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	255, 0, 0, 255  },
 
-		{0.0f, 0.0f, 0.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	  0, 255, 0, 255},
+bool srshader_compile (GLuint shader_id, const char* shader_src) {
-		{0.0f, 1.0f, 0.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	  0, 255, 0, 255},
+  glShaderSource (shader_id, 1, &shader_src, 0);
+  glCompileShader (shader_id);
 
-		{0.0f, 0.0f, 0.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	  0, 0, 255, 255},
+  // Check Vertex Shader
-		{0.0f, 0.0f, 1.0f, 1.0f,	 0.0f, 0.0f, 0.0f,		0.0f, 0.0f,	  0, 0, 255, 255}
+  GLint result = GL_FALSE;
-	};
+  int log_length = 0;
-	GLuint coord_frame_indices[] = { 
+  glGetShaderiv(shader_id, GL_COMPILE_STATUS, &result);
-		0, 1,
+  glGetShaderiv(shader_id, GL_INFO_LOG_LENGTH, &log_length);
-		1, 2,
+  if ( log_length > 0 ){
-		3, 4
+    char* err_msg = calloc (log_length, sizeof(char));
-	};
+    assert (err_msg);
+    glGetShaderInfoLog(shader_id, log_length, NULL, err_msg);
+    gLog("%s", err_msg);
+    free (err_msg);
 
-	gCoordFrameMesh.vertices = malloc (sizeof(coord_frame_vertices));
+    return false;
-	memcpy (gCoordFrameMesh.vertices, coord_frame_vertices, sizeof(coord_frame_vertices));
+  }
 
-	gCoordFrameMesh.indices = malloc (sizeof(coord_frame_indices));
+  return true;
-	memcpy (gCoordFrameMesh.indices, coord_frame_indices, sizeof (coord_frame_indices));
+}
+
+bool srshader_load (srshader* shader, const char* vert_src, const char* frag_src) {
+  shader->vert_shader_id = glCreateShader(GL_VERTEX_SHADER);
+  if (!srshader_compile(shader->vert_shader_id, vert_src)) {
+    gLog("Error compiling vertex shader!");
+    return false;
+  }
+
+  shader->frag_shader_id = glCreateShader(GL_FRAGMENT_SHADER);
+  if (!srshader_compile(shader->frag_shader_id, frag_src)) {
+    gLog("Error compiling fragment shader!");
+    return false;
+  }
+
+  shader->program_id = glCreateProgram();
+  glAttachShader(shader->program_id, shader->vert_shader_id);
+  glAttachShader(shader->program_id, shader->frag_shader_id);
+
+  // Bind attribute locations
+  glBindAttribLocation(shader->program_id, 0, "inCoord");
+  glBindAttribLocation(shader->program_id, 1, "inNormal");
+  glBindAttribLocation(shader->program_id, 2, "inUV");
+  glBindAttribLocation(shader->program_id, 3, "inColor");
+
+  glLinkProgram(shader->program_id);
+
+  GLint result = GL_FALSE;
+  int log_length = 0;
+  glGetProgramiv(shader->program_id, GL_LINK_STATUS, &result);
+  glGetProgramiv(shader->program_id, GL_INFO_LOG_LENGTH, &log_length);
+  if ( log_length > 0 ){
+    char* err_msg = calloc (log_length, sizeof(char));
+    assert (err_msg);
+    glGetProgramInfoLog(shader->program_id, log_length, NULL, err_msg);
+    gLog("%s", err_msg);
+    free (err_msg);
+    gLog("Error linking shader program!");
+
+    return false;
+  }
+
+  return true;
+}
+
+bool try_read_file (const char* dir, const char* filename, char** buf) {
+  assert (*buf == NULL);
+
+  int path_len = strlen(dir) + strlen(filename) + 1;
+  char* path_buffer = calloc (path_len, sizeof(char));
+  snprintf (path_buffer, path_len, "%s%s", dir, filename);
+  long file_length = 0;
+
+  FILE* file = NULL;
+  file = fopen(path_buffer, "rb");
+  if (file) {
+    fseek(file, 0, SEEK_END);
+    file_length = ftell(file);
+    fseek(file, 0, SEEK_SET);
+    *buf = calloc(file_length, sizeof(char));
+    assert (*buf);
+    fread (*buf, 1, file_length, file);
+    fclose(file);
+
+    return true;
+  }
+
+  return false;
+}
+
+void init_shaders() {
+  static const char* shader_search_paths[] = {
+      "./data/shaders/",
+      "../data/shaders/",
+      NULL};
+
+  bool found = false;
+  int search_index = 0;
+  char* frag_buffer = NULL;
+  char* vert_buffer = NULL;
+
+  while (shader_search_paths[search_index] != NULL) {
+    const char* dir = shader_search_paths[search_index];
+    static char path_buf[1024];
+    long length;
+
+    if (vert_buffer == NULL) {
+      try_read_file (dir, gDefaultShader.vert_fname, &vert_buffer);
+    }
+    if (frag_buffer == NULL) {
+      try_read_file (dir, gDefaultShader.frag_fname, &frag_buffer);
+    }
+
+    if ((vert_buffer != NULL) && (frag_buffer != NULL)) {
+      srshader_load (&gDefaultShader, vert_buffer, frag_buffer);
+
+      free (vert_buffer);
+      vert_buffer = NULL;
+      free (frag_buffer);
+      frag_buffer = NULL;
+      break;
+    }
+
+    search_index++;
+  }
+
+  if (gDefaultShader.program_id == 0) {
+    gLog ("Error: could not load default shader!");
+  }
+}
+
+void init_debug_meshes() {
+  assert(gCoordFrameMesh.nvertices == 0);
+
+  gCoordFrameMesh.nvertices = 6;
+
+  srvrtxdata coord_frame_vertices[] = {
+      {0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 255, 0, 0, 255},
+      {1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 255, 0, 0, 255},
+
+      {0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0, 255, 0, 255},
+      {0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0, 255, 0, 255},
+
+      {0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0, 0, 255, 255},
+      {0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0, 0, 255, 255}};
+  GLuint coord_frame_indices[] = {0, 1, 1, 2, 3, 4};
+
+  glGenBuffers(1, &gCoordFrameMesh.vertex_buffer_id);
+  glBindBuffer(GL_ARRAY_BUFFER, gCoordFrameMesh.vertex_buffer_id);
+  glBufferData(
+      GL_ARRAY_BUFFER,
+      sizeof(coord_frame_vertices),
+      coord_frame_vertices,
+      GL_STATIC_DRAW);
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+  glGenBuffers(1, &gCoordFrameMesh.index_buffer_id);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gCoordFrameMesh.index_buffer_id);
+  glBufferData(
+      GL_ELEMENT_ARRAY_BUFFER,
+      sizeof(coord_frame_indices),
+      coord_frame_indices,
+      GL_STATIC_DRAW);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 };
 
 //
@@ -95,7 +244,8 @@ void init_debug_meshes () {
 srndr* srndr_create() {
   srndr* result = calloc(1, sizeof(srndr));
 
-	init_debug_meshes();
+  init_shaders();
+  init_debug_meshes();
 
   return result;
 }
@@ -109,13 +259,9 @@ void srview_get_output_texture(srview* sv, GLuint* texture) {
   *texture = sv->mColorTexture;
 }
 
-void srview_set_proj(srview* sv, simd4x4f proj) {
+void srview_set_proj(srview* sv, simd4x4f proj) { sv->proj = proj; }
-	sv->proj = proj;
-}
 
-void srview_set_view(srview* sv, simd4x4f view) {
+void srview_set_view(srview* sv, simd4x4f view) { sv->view = view; }
-	sv->view = view;
-}
 
 void srview_update_framebuffer(srview* sv) {
   glGenFramebuffers(1, &sv->mFrameBufferId);
@@ -202,15 +348,11 @@ void srview_set_size(srview* sv, int width, int height) {
     return;
   }
 
-  gLog("Setting size to %d, %d", width, height);
-
   sv->width = width;
   sv->height = height;
 
   srview_cleanup_framebuffer(sv);
   srview_update_framebuffer(sv);
-
-  gLog("Color texture = %d", sv->mColorTexture);
 }
 
 srview* srview_create() {
@@ -225,12 +367,86 @@ void srview_destroy(srview* sv) {
   free(sv);
 }
 
+void srndr_run_frame_command(const srcmd* cmd) {
+  glBindBuffer(GL_ARRAY_BUFFER, gCoordFrameMesh.vertex_buffer_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)
+  );
+
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gCoordFrameMesh.index_buffer_id);
+  glDrawElements(GL_LINES, 6, GL_UNSIGNED_INT, (void*)0);
+}
+
 void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf) {
   glBindFramebuffer(GL_DRAW_FRAMEBUFFER, sview->mFrameBufferId);
 
   glViewport(0, 0, sview->width, sview->height);
-  glClearColor(1.f, 0.f, 1.f, 1.f);
+  glClearColor(0.1f, 0.1f, 0.1f, 0.1f);
-  glClear(GL_COLOR_BUFFER_BIT);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  glUseProgram(gDefaultShader.program_id);
+  GLint view_mat_loc = glGetUniformLocation(gDefaultShader.program_id, "uViewMatrix");
+  assert (view_mat_loc != -1);
+  glUniformMatrix4fv(view_mat_loc, 1, GL_FALSE, &sview->view);
+
+  GLint proj_mat_loc = glGetUniformLocation(gDefaultShader.program_id, "uProjectionMatrix");
+  assert (proj_mat_loc != -1);
+  glUniformMatrix4fv(proj_mat_loc, 1, GL_FALSE, &sview->proj);
+
+  GLint model_mat_loc = glGetUniformLocation(gDefaultShader.program_id, "uModelMatrix");
+  assert (model_mat_loc != -1);
+
+  for (int i = 0; i < scmdbuf->ncmds; i++) {
+    const srcmd* cmd = &scmdbuf->cmds[i];
+    glUniformMatrix4fv(model_mat_loc, 1, GL_FALSE, &cmd->mat);
+
+    switch (cmd->type) {
+      case SRndrCmdTypeFrame:
+        srndr_run_frame_command(cmd);
+        break;
+      default:
+        gLog("Invalid command type %d at index %d", cmd->type, i);
+        break;
+    }
+  }
 
   glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 }
@@ -238,23 +454,21 @@ void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf) {
 //
 // Render Commands
 //
-srcmdbuf* srcmdbuf_create (unsigned int size_max) {
+srcmdbuf* srcmdbuf_create(unsigned int size_max) {
-	srcmdbuf* result = malloc (sizeof (srcmdbuf));
+  srcmdbuf* result = malloc(sizeof(srcmdbuf));
-	result->ncmds = size_max;
+  result->ncmds = size_max;
-	result->idx = 0;
+  result->idx = 0;
-	result->cmds = calloc (sizeof (srcmd), size_max);
+  result->cmds = calloc(sizeof(srcmd), size_max);
 
-	return result;
+  return result;
 }
 
-void srcmdbuf_clear (srcmdbuf* cmdbuf) {
+void srcmdbuf_clear(srcmdbuf* cmdbuf) { cmdbuf->idx = 0; }
-	cmdbuf->idx = 0;
-}
 
-srcmd* srcmd_create (srcmdbuf* cmdbuf) {
+srcmd* srcmd_create(srcmdbuf* cmdbuf) {
-	if (cmdbuf->idx == cmdbuf->ncmds) {
+  if (cmdbuf->idx == cmdbuf->ncmds) {
-		gLog ("Warning: number of render commands maxed out!");
+    gLog("Warning: number of render commands maxed out!");
-		return NULL;
+    return NULL;
-	}
+  }
-	return &(cmdbuf->cmds[cmdbuf->idx++]);
+  return &(cmdbuf->cmds[cmdbuf->idx++]);
 }

src/vissim.cc

@@ -56,9 +56,12 @@ static void opengl_error_callback(
     GLsizei length,
     const GLchar* message,
     const void* userParam) {
-  	gLog ("OpenGL Error: %s type %0x%x, severity = 0x%x, message = %s",
+  gLog(
-             ( type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "" ),
+      "OpenGL Error: %s type %0x%x, severity = 0x%x, message = %s",
-              type, severity, message );
+      (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
+      type,
+      severity,
+      message);
 }
 
 static void
@@ -156,26 +159,31 @@ void DoRender() {
   // Render Output
   ImGui::Begin("Render Output");
 
-	// Update the view
+  // Update the view
   const ImVec2 content_avail = ImGui::GetContentRegionAvail();
   srview_set_size(gView, content_avail.x, content_avail.y);
-	simd4x4f view;
+  simd4x4f view;
-	simd4x4f proj;
+  simd4x4f proj;
-	simd4x4f_identity (&view);
+  simd4x4f_translation(&view, 0.1f, 0.1f, -0.1f);
-	simd4x4f_identity (&proj);
+  simd4x4f_lookat(
-	srview_set_view(gView, view);
+      &view,
-	srview_set_view(gView, proj);
+      simd4f_create(1.f, 1.f, 1.f, 1.f),
+      simd4f_create(0.f, 0.f, 0.f, 1.f),
+      simd4f_create(0.f, 1.f, 0.f, 1.f));
+  simd4x4f_ortho(&proj, -5.0f, 5.0f, -5.0f, 5.0f, -5.0f, 5.0f);
+  srview_set_view(gView, view);
+  srview_set_proj(gView, proj);
 
-	// Populate render commands
+  // Populate render commands
-	srcmdbuf_clear(gRndrCmds);
+  srcmdbuf_clear(gRndrCmds);
-	srcmd* cmd = srcmd_create (gRndrCmds);
+  srcmd* cmd = srcmd_create(gRndrCmds);
-	cmd->type = SRndrCmdTypeFrame;
+  cmd->type = SRndrCmdTypeFrame;
-	simd4x4f_identity(&cmd->mat);
+  simd4x4f_identity(&cmd->mat);
-	cmd->color = simd4f_create (1.f, 1.f, 1.f, 1.f);
+  cmd->color = simd4f_create(1.f, 1.f, 1.f, 1.f);
 
-	// Perform the actual render
+  // Perform the actual render
   srndr_render(gRndr, gView, gRndrCmds);
- 	GLuint view_texture;
+  GLuint view_texture;
   srview_get_output_texture(gView, &view_texture);
 
   ImGui::Image(
@@ -267,6 +275,7 @@ int main(void) {
 
   gRndr = srndr_create();
   gView = srview_create();
+  gRndrCmds = srcmdbuf_create(1024);
 
   while (!glfwWindowShouldClose(gWindow)) {
     frame_counter++;