Add a (broken) terrain sample

samples/Makefile

@@ -16,3 +16,4 @@ all:
 	$(KOS_MAKE) -C zclip all
 	$(KOS_MAKE) -C zclip_triangle all
 	$(KOS_MAKE) -C zclip_trianglestrip all
+	$(KOS_MAKE) -C terrain all

samples/terrain/Makefile

@@ -0,0 +1,29 @@
+TARGET = terrain.elf
+OBJS = main.o
+
+all: rm-elf $(TARGET)
+
+include $(KOS_BASE)/Makefile.rules
+
+clean:
+	-rm -f $(TARGET) $(OBJS) romdisk.*
+
+rm-elf:
+	-rm -f $(TARGET) romdisk.*
+
+$(TARGET): $(OBJS) romdisk.o
+	$(KOS_CC) $(KOS_CFLAGS) $(KOS_LDFLAGS) -o $(TARGET) $(KOS_START) \
+		$(OBJS) romdisk.o $(OBJEXTRA) -lm -lkosutils $(KOS_LIBS)
+
+romdisk.img:
+	$(KOS_GENROMFS) -f romdisk.img -d romdisk -v
+
+romdisk.o: romdisk.img
+	$(KOS_BASE)/utils/bin2o/bin2o romdisk.img romdisk romdisk.o
+
+run: $(TARGET)
+	$(KOS_LOADER) $(TARGET)
+
+dist:
+	rm -f $(OBJS) romdisk.o romdisk.img
+	$(KOS_STRIP) $(TARGET)

samples/terrain/main.c

@@ -0,0 +1,142 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "gl.h"
+#include "glu.h"
+#include "glkos.h"
+
+#define TERRAIN_SIZE 250
+#define TERRAIN_SCALE 1.0f
+#define TERRAIN_HEIGHT_SCALE 1.0f
+
+typedef struct {
+    float x, y, z;
+} Vec3;
+
+Vec3 vertices[TERRAIN_SIZE * TERRAIN_SIZE];
+unsigned int indices[TERRAIN_SIZE * TERRAIN_SIZE * 2];
+Vec3 normals[TERRAIN_SIZE * TERRAIN_SIZE];
+
+void GenerateTerrain() {
+    const float OFFSET = (-TERRAIN_SIZE * TERRAIN_SCALE) / 2.0f;
+
+    unsigned int j = 0;
+    unsigned int z, x;
+    for(z = 0; z < TERRAIN_SIZE; ++z) {
+        for(x = 0; x < TERRAIN_SIZE; ++x) {
+            unsigned int i = (z * TERRAIN_SIZE) + x;
+
+            vertices[i].x = (x * TERRAIN_SCALE) + OFFSET;
+            vertices[i].z = (z * TERRAIN_SCALE) + OFFSET;
+            vertices[i].y = (float)rand() / (float)(RAND_MAX / TERRAIN_HEIGHT_SCALE);
+
+            normals[i].x = normals[i].z = 0.0f;
+            normals[i].y = 1.0f;
+
+            if(z > 0) {
+                indices[j++] = (i - TERRAIN_SIZE);
+                indices[j++] = i;
+            }
+        }
+    }
+}
+
+/* A general OpenGL initialization function.  Sets all of the initial parameters. */
+void InitGL(int Width, int Height)	        // We call this right after our OpenGL window is created.
+{
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		// This Will Clear The Background Color To Black
+    glClearDepth(1.0);				// Enables Clearing Of The Depth Buffer
+    glDepthFunc(GL_LEQUAL);				// The Type Of Depth Test To Do
+    glEnable(GL_DEPTH_TEST);			// Enables Depth Testing
+    glShadeModel(GL_SMOOTH);			// Enables Smooth Color Shading
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();				// Reset The Projection Matrix
+
+    gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);	// Calculate The Aspect Ratio Of The Window
+
+    glMatrixMode(GL_MODELVIEW);
+
+    GenerateTerrain();
+
+    /* glEnable(GL_LIGHTING);
+    glEnable(GL_LIGHT0);
+    glDisable(GL_BLEND);
+
+    GLfloat mat_diffuse[] = {0.0, 1.0, 0.0, 1.0};
+    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
+    GLfloat mat_shininess[] = { 50.0 };
+    GLfloat light_position[] = { 1.0, -1.0, 0.0, 0.0 };
+
+    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat_diffuse);
+    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
+    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
+    glLightfv(GL_LIGHT0, GL_POSITION, light_position); */
+
+    fprintf(stderr, "Generated terrain\n");
+}
+
+/* The function called when our window is resized (which shouldn't happen, because we're fullscreen) */
+void ReSizeGLScene(int Width, int Height)
+{
+    if (Height == 0)				// Prevent A Divide By Zero If The Window Is Too Small
+        Height = 1;
+
+    glViewport(0, 0, Width, Height);		// Reset The Current Viewport And Perspective Transformation
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+
+    gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);
+    glMatrixMode(GL_MODELVIEW);
+}
+
+
+/* The main drawing function. */
+void DrawGLScene()
+{
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);		// Clear The Screen And The Depth Buffer
+    glLoadIdentity();				// Reset The View
+
+    glDisable(GL_CULL_FACE);
+
+    glTranslatef(0.0f, -1.0f, 0.0f);
+
+    static float x = 0.0f;
+    x += 1.0f;
+
+    glRotatef(x, 0, 1.0f, 0);
+
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_NORMAL_ARRAY);
+
+    glNormalPointer(GL_FLOAT, 0, normals);
+    glVertexPointer(3, GL_FLOAT, 0, &vertices[0].x);
+
+    unsigned int z;
+    for(z = 0; z < TERRAIN_SIZE; ++z) {
+        glDrawElements(
+            GL_TRIANGLE_STRIP,
+            TERRAIN_SIZE * 2,
+            GL_UNSIGNED_INT,
+            indices + (z * (TERRAIN_SIZE * 2))
+        );
+    }
+
+    // swap buffers to display, since we're double buffered.
+    glKosSwapBuffers();
+}
+
+int main(int argc, char **argv)
+{
+    glKosInit();
+
+    InitGL(640, 480);
+    ReSizeGLScene(640, 480);
+
+    while(1) {
+        DrawGLScene();
+    }
+
+    return 0;
+}