Provide interface to export canvas to openGL.

6 files changed, 457 insertions, 12 deletions

diff --git a/libdimension/Makefile.am b/libdimension/Makefile.am
index 16bf4a7..7a18535 100644
--- a/libdimension/Makefile.am
+++ b/libdimension/Makefile.am
@@ -25,6 +25,7 @@ nobase_include_HEADERS = dimension.h                                           \
                          dimension/color.h                                     \
                          dimension/error.h                                     \
                          dimension/geometry.h                                  \
+                         dimension/gl.h                                        \
                          dimension/png.h                                       \
                          dimension/progress.h                                  \
                          dimension/object.h                                    \
@@ -41,6 +42,7 @@ libdimension_la_SOURCES = $(nobase_include_HEADERS)                            \
                           color.c                                              \
                           error.c                                              \
                           geometry.c                                           \
+                          gl.c                                                 \
                           inlines.c                                            \
                           png.c                                                \
                           progress.c                                           \
@@ -49,4 +51,4 @@ libdimension_la_SOURCES = $(nobase_include_HEADERS)                            \
                           raytrace.c                                           \
                           scene.c
 libdimension_la_LDFLAGS = -version-info 0:0:0
-libdimension_la_LIBADD  = -lm -lpthread -lpng
+libdimension_la_LIBADD  = -lm -lpthread -lpng -lGL
diff --git a/libdimension/dimension.h b/libdimension/dimension.h
index 5734616..869b959 100644
--- a/libdimension/dimension.h
+++ b/libdimension/dimension.h
@@ -57,6 +57,7 @@ extern "C" {
 #include <dimension/geometry.h>
 #include <dimension/color.h>
 #include <dimension/canvas.h>
+#include <dimension/gl.h>
 #include <dimension/png.h>
 #include <dimension/object.h>
 #include <dimension/objects.h>
diff --git a/libdimension/dimension/gl.h b/libdimension/dimension/gl.h
new file mode 100644
index 0000000..e27c418
--- /dev/null
+++ b/libdimension/dimension/gl.h
@@ -0,0 +1,37 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+/*
+ * Draw a canvas to a GL framebuffer with glDrawPixels, or read one with
+ * glReadPixels.  Should be fast, so no _async() versions.
+ */
+
+#ifndef DIMENSION_GL_H
+#define DIMENSION_GL_H
+
+#include <stdio.h>
+
+/* Write canvas to GL framebuffer.  Returns 0 on success, nonzero on failure */
+int dmnsn_gl_write_canvas(const dmnsn_canvas *canvas);
+
+/* Read a canvas from a GL framebuffer.  Returns NULL on failure. */
+dmnsn_canvas *dmnsn_gl_read_canvas();
+
+#endif /* DIMENSION_GL_H */
diff --git a/libdimension/gl.c b/libdimension/gl.c
new file mode 100644
index 0000000..3542a2d
--- /dev/null
+++ b/libdimension/gl.c
@@ -0,0 +1,91 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+#include "dimension.h"
+#include <GL/gl.h>
+
+/* Write canvas to GL framebuffer.  Returns 0 on success, nonzero on failure */
+int
+dmnsn_gl_write_canvas(const dmnsn_canvas *canvas)
+{
+  GLuint *pixels; /* Array of 32-bit ints in RGBA order */
+  GLuint *pixel;
+  dmnsn_sRGB sRGB;
+  dmnsn_color color;
+  unsigned int x, y, width, height;
+
+  width = canvas->x;
+  height = canvas->y;
+
+  pixels = malloc(4*width*height*sizeof(GLuint));
+  if (!pixels) {
+    return 1;
+  }
+
+  for (y = 0; y < height; ++y) {
+    for (x = 0; x < width; ++x) {
+      pixel = pixels + 4*(y*width + x);
+
+      color = dmnsn_get_pixel(canvas, x, y);
+      sRGB = dmnsn_sRGB_from_color(color);
+
+      /* Saturate R, G, and B to [0, UINT32_MAX] */
+
+      if (sRGB.R <= 0.0) {
+        pixel[0] = 0;
+      } else if (sRGB.R >= 1.0) {
+        pixel[0] = UINT32_MAX;
+      } else {
+        pixel[0] = sRGB.R*UINT32_MAX;
+      }
+
+      if (sRGB.G <= 0.0) {
+        pixel[1] = 0;
+      } else if (sRGB.G >= 1.0) {
+        pixel[1] = UINT32_MAX;
+      } else {
+        pixel[1] = sRGB.G*UINT32_MAX;
+      }
+
+      if (sRGB.B <= 0.0) {
+        pixel[2] = 0;
+      } else if (sRGB.B >= 1.0) {
+        pixel[2] = UINT32_MAX;
+      } else {
+        pixel[2] = sRGB.B*UINT32_MAX;
+      }
+
+      /* color.filter + color.trans is in [0.0, 1.0] by definition */
+      pixel[3] = (color.filter + color.trans)*UINT32_MAX;
+    }
+  }
+
+  glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_INT, pixels);
+
+  free(pixels);
+  return 0;
+}
+
+/* Read a canvas from a GL framebuffer.  Returns NULL on failure. */
+dmnsn_canvas *
+dmnsn_gl_read_canvas()
+{
+  return NULL;
+}
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 9e6fda4..6d496f6 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -24,7 +24,8 @@ check_PROGRAMS    = warning-test                                               \
                     png-test                                                   \
                     pngxx-test                                                 \
                     raytrace-test                                              \
-                    raytracexx-test
+                    raytracexx-test                                            \
+                    gl-test
 TESTS             = $(check_PROGRAMS)
 XFAIL_TESTS       = error-test
 
@@ -38,20 +39,23 @@ libdimensionxx_tests_la_SOURCES = testsxx.hpp                                  \
                                   testsxx.cpp
 libdimensionxx_tests_la_LIBADD  = ../libdimensionxx/libdimensionxx.la
 
-warning_test_SOURCES    = warning.c
-warning_test_LDADD      = ./libdimension-tests.la
+warning_test_SOURCES = warning.c
+warning_test_LDADD   = ./libdimension-tests.la
 
-error_test_SOURCES      = error.c
-error_test_LDADD        = ./libdimension-tests.la
+error_test_SOURCES = error.c
+error_test_LDADD   = ./libdimension-tests.la
 
-png_test_SOURCES        = png.c
-png_test_LDADD          = ./libdimension-tests.la
+png_test_SOURCES = png.c
+png_test_LDADD   = ./libdimension-tests.la
 
-pngxx_test_SOURCES      = pngxx.cpp
-pngxx_test_LDADD        = ./libdimensionxx-tests.la
+pngxx_test_SOURCES = pngxx.cpp
+pngxx_test_LDADD   = ./libdimensionxx-tests.la
 
-raytrace_test_SOURCES   = raytrace.c
-raytrace_test_LDADD     = ./libdimension-tests.la
+raytrace_test_SOURCES = raytrace.c
+raytrace_test_LDADD   = ./libdimension-tests.la
 
 raytracexx_test_SOURCES = raytracexx.cpp
 raytracexx_test_LDADD   = ./libdimensionxx-tests.la
+
+gl_test_SOURCES = gl.c
+gl_test_LDADD   = ./libdimension-tests.la
diff --git a/tests/gl.c b/tests/gl.c
new file mode 100644
index 0000000..773a9aa
--- /dev/null
+++ b/tests/gl.c
@@ -0,0 +1,310 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Test Suite.                        *
+ *                                                                       *
+ * Dimension is free software; you can redistribute it and/or modify it  *
+ * under the terms of the GNU Lesser General Public License as published *
+ * by the Free Software Foundation; either version 3 of the License, or  *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * Dimension is distributed in the hope that it will be useful, but      *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+#include "tests.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <GL/glx.h>
+#include <GL/gl.h>
+
+typedef struct {
+  Display *dpy;
+  Window win;
+  Colormap cmap;
+  GLXContext cx;
+  XEvent event;
+} dmnsn_display;
+
+dmnsn_display *dmnsn_new_display(const dmnsn_canvas *canvas);
+void dmnsn_delete_display(dmnsn_display *display);
+
+void dmnsn_display_frame(dmnsn_display *display);
+
+int
+main() {
+  dmnsn_display *display;
+  dmnsn_progress *progress;
+  dmnsn_scene *scene;
+  dmnsn_object *sphere, *cube;
+  dmnsn_sRGB sRGB;
+  dmnsn_color color;
+  dmnsn_matrix trans;
+  unsigned int i;
+
+  /* Set the resilience low for tests */
+  dmnsn_set_resilience(DMNSN_SEVERITY_LOW);
+
+  /* Allocate our new scene */
+  scene = dmnsn_new_scene();
+  if (!scene) {
+    fprintf(stderr, "--- Allocation of scene failed! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  /* Allocate a canvas */
+  scene->canvas = dmnsn_new_canvas(768, 480);
+  if (!scene->canvas) {
+    dmnsn_delete_scene(scene);
+    fprintf(stderr, "--- Allocation of canvas failed! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  /* Set up the transformation matrix for the perspective camera */
+  trans = dmnsn_scale_matrix(
+    dmnsn_vector_construct(
+      ((double)scene->canvas->x)/scene->canvas->y, 1.0, 1.0
+    )
+  );
+  trans = dmnsn_matrix_mul(
+    dmnsn_translation_matrix(dmnsn_vector_construct(0.0, 0.0, -4.0)),
+    trans
+  );
+  trans = dmnsn_matrix_mul(
+    dmnsn_rotation_matrix(dmnsn_vector_construct(0.0, 1.0, 0.0)),
+    trans
+  );
+
+  /* Create a perspective camera */
+  scene->camera = dmnsn_new_perspective_camera(trans);
+  if (!scene->camera) {
+    dmnsn_delete_canvas(scene->canvas);
+    dmnsn_delete_scene(scene);
+    fprintf(stderr, "--- Allocation of camera failed! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  /* Background color */
+  sRGB.R = 0.0;
+  sRGB.G = 0.0;
+  sRGB.B = 0.1;
+  color = dmnsn_color_from_sRGB(sRGB);
+  color.filter = 0.1;
+  scene->background = color;
+
+  /* Now make our objects */
+
+  sphere = dmnsn_new_sphere();
+  if (!sphere) {
+    dmnsn_delete_perspective_camera(scene->camera);
+    dmnsn_delete_canvas(scene->canvas);
+    dmnsn_delete_scene(scene);
+    fprintf(stderr, "--- Allocation of sphere failed! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  sphere->trans = dmnsn_matrix_inverse(
+    dmnsn_scale_matrix(dmnsn_vector_construct(1.25, 1.25, 1.25))
+  );
+  dmnsn_array_push(scene->objects, &sphere);
+
+  cube = dmnsn_new_cube();
+  if (!cube) {
+    dmnsn_delete_sphere(sphere);
+    dmnsn_delete_perspective_camera(scene->camera);
+    dmnsn_delete_canvas(scene->canvas);
+    dmnsn_delete_scene(scene);
+    fprintf(stderr, "--- Allocation of cube failed! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  cube->trans = dmnsn_matrix_inverse(
+    dmnsn_rotation_matrix(dmnsn_vector_construct(0.75, 0.0, 0.0))
+  );
+  dmnsn_array_push(scene->objects, &cube);
+
+  display = dmnsn_new_display(scene->canvas);
+  if (!display) {
+    dmnsn_delete_cube(cube);
+    dmnsn_delete_sphere(sphere);
+    dmnsn_delete_perspective_camera(scene->camera);
+    dmnsn_delete_canvas(scene->canvas);
+    dmnsn_delete_scene(scene);
+    fprintf(stderr, "--- Couldn't initialize X or GLX! ---\n");
+    return EXIT_FAILURE;
+  }
+
+  for (i = 0; i < 48; ++i) {
+    progress = dmnsn_raytrace_scene_async(scene);
+    if (!progress) {
+      dmnsn_delete_display(display);
+      dmnsn_delete_cube(cube);
+      dmnsn_delete_sphere(sphere);
+      dmnsn_delete_perspective_camera(scene->camera);
+      dmnsn_delete_canvas(scene->canvas);
+      dmnsn_delete_scene(scene);
+      fprintf(stderr, "--- Couldn't start raytracing worker thread! ---\n");
+      return EXIT_FAILURE;
+    }
+
+    progressbar("Raytracing scene: ", progress);
+
+    if (dmnsn_finish_progress(progress) != 0) {
+      dmnsn_delete_display(display);
+      dmnsn_delete_cube(cube);
+      dmnsn_delete_sphere(sphere);
+      dmnsn_delete_perspective_camera(scene->camera);
+      dmnsn_delete_canvas(scene->canvas);
+      dmnsn_delete_scene(scene);
+      fprintf(stderr, "--- Raytracing failed! ---\n");
+      return EXIT_FAILURE;
+    }
+
+    if (dmnsn_gl_write_canvas(scene->canvas) != 0) {
+      dmnsn_delete_display(display);
+      dmnsn_delete_cube(cube);
+      dmnsn_delete_sphere(sphere);
+      dmnsn_delete_perspective_camera(scene->camera);
+      dmnsn_delete_canvas(scene->canvas);
+      dmnsn_delete_scene(scene);
+      fprintf(stderr, "--- Drawing to openGL failed! ---\n");
+      return EXIT_FAILURE;
+    }
+    dmnsn_display_frame(display);
+
+    /* Rotate the cube and camera for the next frame */
+
+    cube->trans = dmnsn_matrix_mul(
+      dmnsn_matrix_inverse(
+        dmnsn_rotation_matrix(dmnsn_vector_construct(0.025, 0.0, 0.0))
+      ),
+      cube->trans
+    );
+
+    trans = dmnsn_matrix_mul(
+      dmnsn_rotation_matrix(dmnsn_vector_construct(0.0, -0.05, 0.0)),
+      trans
+    );
+    dmnsn_set_perspective_camera_trans(scene->camera, trans);
+  }
+
+  dmnsn_delete_display(display);
+  dmnsn_delete_cube(cube);
+  dmnsn_delete_sphere(sphere);
+  dmnsn_delete_perspective_camera(scene->camera);
+  dmnsn_delete_canvas(scene->canvas);
+  dmnsn_delete_scene(scene);
+  return EXIT_SUCCESS;
+}
+
+static Bool
+WaitForNotify(Display *d, XEvent *e, char *arg)
+{
+  return (e->type == MapNotify) && (e->xmap.window == (Window)arg);
+}
+
+dmnsn_display *
+dmnsn_new_display(const dmnsn_canvas *canvas)
+{
+  int attributeList[] = {
+    GLX_RGBA,
+    GLX_DOUBLEBUFFER,
+    GLX_RED_SIZE, 1,
+    GLX_GREEN_SIZE, 1,
+    GLX_BLUE_SIZE, 1,
+    None
+  };
+  dmnsn_display *display;
+  XVisualInfo *vi;
+  XSetWindowAttributes swa;
+
+  display = malloc(sizeof(dmnsn_display));
+  if (!display) {
+    return NULL;
+  }
+
+  /* Get an X connection */
+  display->dpy = XOpenDisplay(0);
+  if (!display->dpy) {
+    free(display);
+    return NULL;
+  }
+
+  /* Get an appropriate visual */
+  vi = glXChooseVisual(display->dpy, DefaultScreen(display->dpy),
+                       attributeList);
+  if (!vi) {
+    XCloseDisplay(display->dpy);
+    free(display);
+    return NULL;
+  }
+
+  /* Create a GLX context */
+  display->cx = glXCreateContext(display->dpy, vi, 0, GL_TRUE);
+  if (!display->cx) {
+    XCloseDisplay(display->dpy);
+    free(display);
+    return NULL;
+  }
+
+  /* Create a color map */
+  display->cmap = XCreateColormap(display->dpy,
+                                  RootWindow(display->dpy, vi->screen),
+                                  vi->visual, AllocNone);
+  if (!display->cmap) {
+    glXDestroyContext(display->dpy, display->cx);
+    XCloseDisplay(display->dpy);
+    free(display);
+    return NULL;
+  }
+
+  /* Create a window */
+  swa.colormap = display->cmap;
+  swa.border_pixel = 0;
+  swa.event_mask = StructureNotifyMask;
+  display->win = XCreateWindow(display->dpy,
+                               RootWindow(display->dpy, vi->screen),
+                               0, 0, canvas->x, canvas->y,
+                               0, vi->depth, InputOutput, vi->visual,
+                               CWBorderPixel|CWColormap|CWEventMask, &swa);
+  if (!display->win) {
+    XFreeColormap(display->dpy, display->cmap);
+    glXDestroyContext(display->dpy, display->cx);
+    XCloseDisplay(display->dpy);
+    free(display);
+    return NULL;
+  }
+
+  XMapWindow(display->dpy, display->win);
+  XIfEvent(display->dpy, &display->event, WaitForNotify, (char*)display->win);
+
+  /* Connect the context to the window */
+  glXMakeCurrent(display->dpy, display->win, display->cx);
+
+  return display;
+}
+
+void
+dmnsn_delete_display(dmnsn_display *display)
+{
+  if (display) {
+    XDestroyWindow(display->dpy, display->win);
+    XFreeColormap(display->dpy, display->cmap);
+    glXDestroyContext(display->dpy, display->cx);
+    XCloseDisplay(display->dpy);
+    free(display);
+  }
+}
+
+void
+dmnsn_display_frame(dmnsn_display *display)
+{
+  glFlush();
+  glXSwapBuffers(display->dpy, display->win);
+}