First steps for rendering

CMakeLists.txt

@@ -52,11 +52,13 @@ target_include_directories(
 		PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/3rdparty/rbdl/include>
 		PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/glfw/deps>
 		PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/imgui>
+		PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/vectorial/include>
 		)
 target_link_libraries(vissim ${PROJECT_NAME} glfw)
 
 target_sources(vissim PRIVATE 
 	src/utils.cc
+	src/srender.c
 	3rdparty/glfw/deps/glad_gl.c
 	3rdparty/imgui/imgui.cpp
 	3rdparty/imgui/imgui_draw.cpp

src/srender.c

@@ -0,0 +1,153 @@
+// clang-format off
+#include <glad/gl.h>
+// clang-format on
+
+#include "srender.h"
+
+#include "utils.h"
+#include <assert.h>
+
+typedef struct srndr {
+} srndr;
+
+typedef struct srview {
+  GLuint width;
+  GLuint height;
+
+  GLuint mFrameBufferId;
+  GLuint mColorTexture;
+  GLuint mDepthTexture;
+} srveiw;
+
+typedef struct srcmdbuf {
+} srcmdbuf;
+
+srndr* srndr_create() {
+  srndr* result = calloc(1, sizeof(srndr));
+
+  return result;
+}
+
+void srndr_destroy(srndr* sr) { free(sr); }
+
+void srview_get_output_texture(srview* sv, GLuint* texture) {
+  *texture = sv->mColorTexture;
+}
+
+void srview_update_framebuffer(srview* sv) {
+  glGenFramebuffers(1, &sv->mFrameBufferId);
+  glBindFramebuffer(GL_FRAMEBUFFER, sv->mFrameBufferId);
+
+  // Color Texture
+  glGenTextures(1, &sv->mColorTexture);
+  glBindTexture(GL_TEXTURE_2D, sv->mColorTexture);
+
+  glTexImage2D(
+      GL_TEXTURE_2D,
+      0,
+      GL_RGB,
+      sv->width,
+      sv->height,
+      0,
+      GL_RGB,
+      GL_UNSIGNED_BYTE,
+      0);
+
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+  glFramebufferTexture2D(
+      GL_FRAMEBUFFER,
+      GL_COLOR_ATTACHMENT0,
+      GL_TEXTURE_2D,
+      sv->mColorTexture,
+      0);
+
+  // Depth Texture
+  glGenTextures(1, &sv->mDepthTexture);
+  glBindTexture(GL_TEXTURE_2D, sv->mDepthTexture);
+
+  glTexImage2D(
+      GL_TEXTURE_2D,
+      0,
+      GL_DEPTH_COMPONENT,
+      sv->width,
+      sv->height,
+      0,
+      GL_DEPTH_COMPONENT,
+      GL_FLOAT,
+      0);
+
+  // Set parameters so that we can set a shadow2DSampler
+  glTexParameteri(
+      GL_TEXTURE_2D,
+      GL_TEXTURE_COMPARE_MODE,
+      GL_COMPARE_REF_TO_TEXTURE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+  float border_color[] = {1.0f, 1.0f, 1.0f, 1.0f};
+  glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
+
+  glFramebufferTexture2D(
+      GL_FRAMEBUFFER,
+      GL_DEPTH_ATTACHMENT,
+      GL_TEXTURE_2D,
+      sv->mDepthTexture,
+      0);
+}
+
+void srview_cleanup_framebuffer(srview* sv) {
+  if (glIsFramebuffer(sv->mFrameBufferId)) {
+    glDeleteFramebuffers(1, &sv->mFrameBufferId);
+  }
+
+  if (sv->mColorTexture != -1) {
+    glDeleteTextures(1, &sv->mColorTexture);
+    sv->mColorTexture = -1;
+  }
+
+  if (sv->mDepthTexture != -1) {
+    glDeleteTextures(1, &sv->mDepthTexture);
+    sv->mDepthTexture = -1;
+  }
+}
+
+void srview_set_size(srview* sv, int width, int height) {
+  if (sv->width == width && sv->height == 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() {
+  srview* result = calloc(1, sizeof(srview));
+
+  return result;
+}
+
+void srview_destroy(srview* sv) {
+  srview_cleanup_framebuffer(sv);
+
+  free(sv);
+}
+
+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);
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+}

src/srender.h

@@ -0,0 +1,54 @@
+#ifndef SRENDER_H
+#define SRENDER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct srndr srndr;
+typedef struct srview srview;
+typedef struct srcmdbuf srcmdbuf;
+
+typedef enum {
+  SRndrCmdTypeGrid = 0,
+  SRndrCmdTypeBox,
+  SRndrCmdTypeLight,
+  SRndrCmdTypeSphere
+} SRndrCmdType;
+
+typedef struct srcmd {
+  float mat[16];
+  float color[4];
+  SRndrCmdType cmd_type;
+} srcmd;
+
+//
+// Renderer
+//
+srndr* srndr_create();
+void srndr_destroy(srndr* sr);
+
+//
+// View
+//
+srview* srview_create();
+void srview_destroy(srview* sv);
+
+void srview_set_proj(srview* sv, float* proj);
+void srview_set_view(srview* sv, float* view);
+void srview_set_size(srview* sv, int width, int height);
+void srview_get_output_texture(srview* sv, GLuint* texture);
+
+//
+// Command Buffer and Commands
+//
+srcmdbuf* srcmdbuf_create(unsigned int size_max);
+srcmd* srcmd_create(srcmdbuf* cmdbuf);
+
+void srndr_render(srndr* srndr, srview* sview, srcmdbuf* scmdbuf);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/utils.h

@@ -15,13 +15,6 @@
 extern "C" {
 #endif
 
-struct Timer {
-  float mCurrentTime = 0.0f;
-  float mFrameTime = 0.0f;
-  float mDeltaTime = 0.0f;
-  bool mPaused = false;
-};
-
 typedef struct {
   int32_t mousedX;
   int32_t mousedY;

src/vissim.cc

@@ -18,12 +18,25 @@
 #include "backends/imgui_impl_opengl3.h"
 #include "imgui.h"
 #include "utils.h"
+#include "srender.h"
+
+struct Timer {
+  float mCurrentTime = 0.0f;
+  float mFrameTime = 0.0f;
+  float mDeltaTime = 0.0f;
+  bool mPaused = false;
+};
 
 Timer* gTimer = nullptr;
 GLFWwindow* gWindow = nullptr;
 GuiInputState* gGuiInputState = nullptr;
 double gTimeAtStart = 0;
 
+// Rendering
+srndr* gRndr = nullptr;
+srview* gView = nullptr;
+srcmdbuf* gRndrCmds = nullptr;
+
 double mouse_scroll_x = 0.;
 double mouse_scroll_y = 0.;
 
@@ -139,6 +152,25 @@ void ShowDockspace(bool open) {
   ImGui::End();
 }
 
+void DoRender() {
+  // Render Output
+  ImGui::Begin("Render Output");
+  const ImVec2 content_avail = ImGui::GetContentRegionAvail();
+  GLuint view_texture;
+
+  srview_set_size(gView, content_avail.x, content_avail.y);
+  srndr_render(gRndr, gView, gRndrCmds);
+  srview_get_output_texture(gView, &view_texture);
+
+  ImGui::Image(
+      (void*)view_texture,
+      content_avail,
+      ImVec2(0.0f, 1.0f),
+      ImVec2(1.0f, 0.0f));
+
+  ImGui::End();
+}
+
 int main(void) {
   gTimeAtStart = gGetCurrentTime();
   std::cout << "Time at start: " << gTimeAtStart << std::endl;
@@ -217,6 +249,9 @@ int main(void) {
   bool show_demo_window = true;
   ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
+  gRndr = srndr_create();
+  gView = srview_create();
+
   while (!glfwWindowShouldClose(gWindow)) {
     frame_counter++;
 
@@ -257,11 +292,7 @@ int main(void) {
 
     ShowDockspace(true);
 
-    ImGui::Begin("yoyoyo");
-    ImGui::End();
-
-    ImGui::Begin("yoyoyo3333");
-    ImGui::End();
+    DoRender();
 
     glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 
@@ -295,6 +326,9 @@ int main(void) {
 
   gLog("Exiting application");
 
+  srview_destroy(gView);
+  srndr_destroy(gRndr);
+
   ImGui_ImplOpenGL3_Shutdown();
   ImGui_ImplGlfw_Shutdown();
   ImGui::DestroyContext();