Add helloTerminal

programs/helloTerminal.c

@@ -0,0 +1,120 @@
+/*
+  Simple example of small3dlib, rendering in terminal.
+
+  license: CC0 1.0
+*/
+
+#include <unistd.h>  // for usleep
+
+// we need to define screen resolution before including the library:
+
+#define S3L_RESOLUTION_X 80
+#define S3L_RESOLUTION_Y 40
+
+// and a name of the function we'll be using to draw individual pixels:
+
+#define S3L_PIXEL_FUNCTION drawPixel
+
+// now include the library:
+
+#include "../small3dlib.h"
+
+// we'll use a predefined geometry of a cube that's in the library:
+
+S3L_Unit cubeVertices[] = { S3L_CUBE_VERTICES(S3L_FRACTIONS_PER_UNIT) };
+S3L_Index cubeTriangles[] = { S3L_CUBE_TRIANGLES };
+
+S3L_Model3D cubeModel; // 3D model, has a geometry, position, rotation etc.
+S3L_Scene scene;       // scene we'll be rendring (can have multiple models)
+
+uint8_t screen[S3L_RESOLUTION_X * S3L_RESOLUTION_Y];    // our screen
+
+/* This function will be called by the library to draw individual rasterized
+ pixels to the screen. We should try to make this function as fast as possible
+ as it tends to be the performance bottle neck. */
+
+void drawPixel(S3L_PixelInfo *p)
+{
+  uint8_t c;  // ASCII pixel we'll write to the screen
+
+  /* We'll draw different triangles with different ASCII symbols to give the
+  illusion of lighting. */
+
+  if (p->triangleIndex == 0 || p->triangleIndex == 1 ||
+      p->triangleIndex == 4 || p->triangleIndex == 5)
+    c = '#';
+  else if (p->triangleIndex == 2 || p->triangleIndex == 3 ||
+      p->triangleIndex == 6 || p->triangleIndex == 7)
+    c = 'x';
+  else
+    c = '.';
+
+  screen[p->y * S3L_RESOLUTION_X + p->x] = c; // draw the pixel to the screen
+}
+
+void clearScreen()
+{
+  for (int j = 0; j < S3L_RESOLUTION_X * S3L_RESOLUTION_Y; ++j)
+    screen[j] = ' ';
+}
+
+// This function prints out the content of the screen to the terminal.
+
+void drawScreen()
+{
+  for (int i = 0; i < 20; ++i)
+    printf("\n");
+
+  int pos = 0;
+
+  for (int y = 0; y < S3L_RESOLUTION_Y; ++y)
+  {
+    for (int x = 0; x < S3L_RESOLUTION_X; ++x)
+    {
+      printf("%c",screen[pos]);
+      pos++;      
+    }
+
+    printf("\n");
+  }
+}
+
+int main()
+{
+  S3L_initModel3D(
+    cubeVertices,
+    S3L_CUBE_VERTEX_COUNT,
+    cubeTriangles,
+    S3L_CUBE_TRIANGLE_COUNT,
+    &cubeModel); 
+
+  S3L_initScene(  // Initialize the scene we'll be rendering.
+    &cubeModel,   /* We only have one model (the cube), this is like an array
+                     with only one model in it. */
+    1,
+    &scene);
+
+  // shift the camera a little bit backwards so that it's not inside the cube:
+
+  scene.camera.transform.translation.z = -2 * S3L_FRACTIONS_PER_UNIT;
+
+  for (int i = 0; i < 200; ++i)   // render 200 frames
+  {
+    clearScreen();
+
+    S3L_drawScene(scene);  /* This starts the scene rendering. The drawPixel
+                              function will be called to draw it. */
+    drawScreen();
+
+    usleep(100000);        // wait a bit to let the user see the frame
+
+    // now move and rotate the cube a little to see some movement:
+
+    scene.models[0].transform.rotation.y += 10;
+    scene.models[0].transform.rotation.x += 4;
+    scene.models[0].transform.translation.x = S3L_sin(i * 4);
+    scene.models[0].transform.translation.y = S3L_sin(i * 2) / 2;
+  }
+
+  return 0;
+}

programs/modelViewer.c

@@ -417,7 +417,7 @@ int main()
 
   S3L_normalizeVec3(&toLight);
 
-  S3L_initCamera(&scene.camera);
+  S3L_initScene(&model,1,&scene);
 
   scene.camera.transform.translation.z = -S3L_FRACTIONS_PER_UNIT * 8;
 
@@ -425,9 +425,6 @@ int main()
   catModel.vertices = catVertices;
   animate(0);
 
-  scene.modelCount = 1;
-  scene.models = &model;
-
   int8_t modelIndex = 0;
   int8_t modelsTotal = 4;
   setModel(0);

small3dlib.h

@@ -390,7 +390,7 @@ typedef struct
   S3L_Transform3D transform;
 } S3L_Camera;
 
-static inline void S3L_initCamera(S3L_Camera *c);
+void S3L_initCamera(S3L_Camera *camera);
 
 typedef struct
 {
@@ -414,6 +414,13 @@ typedef struct
   S3L_DrawConfig config;
 } S3L_Model3D;                ///< Represents a 3D model.
 
+void S3L_initModel3D(
+  S3L_Unit *vertices,
+  S3L_Unit vertexCount,
+  S3L_Index *triangles,
+  S3L_Index triangleCount,
+  S3L_Model3D *model);
+
 typedef struct
 {
   S3L_Model3D *models;
@@ -421,6 +428,11 @@ typedef struct
   S3L_Camera camera;
 } S3L_Scene;                  ///< Represent the 3D scene to be rendered.
 
+void S3L_initScene(
+  S3L_Model3D *models,
+  S3L_Index modelCount,
+  S3L_Scene *scene);
+
 typedef struct
 {
   S3L_ScreenCoord x;          ///< Screen X coordinate.
@@ -1319,10 +1331,10 @@ void S3L_setTransform3D(
   t->scale.z = sz;
 }
 
-void S3L_initCamera(S3L_Camera *c)
+void S3L_initCamera(S3L_Camera *camera)
 {
-  c->focalLength = S3L_FRACTIONS_PER_UNIT;
+  camera->focalLength = S3L_FRACTIONS_PER_UNIT;
-  S3L_initTransoform3D(&(c->transform));
+  S3L_initTransoform3D(&(camera->transform));
 }
 
 void S3L_rotationToDirections(
@@ -1373,6 +1385,32 @@ void S3L_initPixelInfo(S3L_PixelInfo *p) // TODO: maybe non-pointer for p
   p->previousZ = 0;
 }
 
+void S3L_initModel3D(
+  S3L_Unit *vertices,
+  S3L_Unit vertexCount,
+  S3L_Index *triangles,
+  S3L_Index triangleCount,
+  S3L_Model3D *model)
+{
+  model->vertices = vertices;
+  model->vertexCount = vertexCount;
+  model->triangles = triangles;
+  model->triangleCount = triangleCount;
+  
+  S3L_initTransoform3D(&(model->transform));
+  S3L_initDrawConfig(&(model->config));
+}
+
+void S3L_initScene(
+  S3L_Model3D *models,
+  S3L_Index modelCount,
+  S3L_Scene *scene)
+{
+  scene->models = models;
+  scene->modelCount = modelCount;
+  S3L_initCamera(&(scene->camera));
+}
+
 void S3L_initDrawConfig(S3L_DrawConfig *config)
 {
   config->backfaceCulling = 2;