1 files changed, 170 insertions, 0 deletions
diff --git a/examples/demo_utils.h b/examples/demo_utils.h
new file mode 100644
index 0000000..94be68e
--- /dev/null
+++ b/examples/demo_utils.h
@@ -0,0 +1,170 @@
+/*
+  Copyright 2012-2019 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "pugl/pugl.h"
+
+#include <math.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+typedef struct {
+	double lastReportTime;
+} PuglFpsPrinter;
+
+typedef float vec4[4];
+typedef vec4  mat4[4];
+
+// clang-format off
+
+static const float cubeStripVertices[] = {
+	-1.0f,  1.0f,  1.0f, // Front top left
+	 1.0f,  1.0f,  1.0f, // Front top right
+	-1.0f, -1.0f,  1.0f, // Front bottom left
+	 1.0f, -1.0f,  1.0f, // Front bottom right
+	 1.0f, -1.0f, -1.0f, // Back bottom right
+	 1.0f,  1.0f,  1.0f, // Front top right
+	 1.0f,  1.0f, -1.0f, // Back top right
+	-1.0f,  1.0f,  1.0f, // Front top left
+	-1.0f,  1.0f, -1.0f, // Back top left
+	-1.0f, -1.0f,  1.0f, // Front bottom left
+	-1.0f, -1.0f, -1.0f, // Back bottom left
+	 1.0f, -1.0f, -1.0f, // Back bottom right
+	-1.0f,  1.0f, -1.0f, // Back top left
+	 1.0f,  1.0f, -1.0f  // Back top right
+};
+
+static const float cubeFrontLineLoop[] = {
+	-1.0f,  1.0f,  1.0f, // Front top left
+	 1.0f,  1.0f,  1.0f, // Front top right
+	 1.0f, -1.0f,  1.0f, // Front bottom right
+	-1.0f, -1.0f,  1.0f, // Front bottom left
+};
+
+static const float cubeBackLineLoop[] = {
+	-1.0f,  1.0f, -1.0f, // Back top left
+	 1.0f,  1.0f, -1.0f, // Back top right
+	 1.0f, -1.0f, -1.0f, // Back bottom right
+	-1.0f, -1.0f, -1.0f, // Back bottom left
+};
+
+static const float cubeSideLines[] = {
+	-1.0f,  1.0f,  1.0f, // Front top left
+	-1.0f,  1.0f, -1.0f, // Back top left
+
+	-1.0f, -1.0f,  1.0f, // Front bottom left
+	-1.0f, -1.0f, -1.0f, // Back bottom left
+
+	 1.0f,  1.0f,  1.0f, // Front top right
+	 1.0f,  1.0f, -1.0f, // Back top right
+
+	 1.0f, -1.0f,  1.0f, // Front bottom right
+	 1.0f, -1.0f, -1.0f, // Back bottom right
+};
+
+// clang-format on
+
+static inline void
+mat4Identity(mat4 m)
+{
+	for (int c = 0; c < 4; ++c) {
+		for (int r = 0; r < 4; ++r) {
+			m[c][r] = c == r ? 1.0f : 0.0f;
+		}
+	}
+}
+
+static inline void
+mat4Translate(mat4 m, const float x, const float y, const float z)
+{
+	m[3][0] = x;
+	m[3][1] = y;
+	m[3][2] = z;
+}
+
+static inline void
+mat4Mul(mat4 m, mat4 a, mat4 b)
+{
+	for (int c = 0; c < 4; ++c) {
+		for (int r = 0; r < 4; ++r) {
+			m[c][r] = 0.0f;
+			for (int k = 0; k < 4; ++k) {
+				m[c][r] += a[k][r] * b[c][k];
+			}
+		}
+	}
+}
+
+static inline void
+mat4Ortho(mat4        m,
+          const float l,
+          const float r,
+          const float b,
+          const float t,
+          const float n,
+          const float f)
+{
+	m[0][0] = 2.0f / (r - l);
+	m[0][1] = m[0][2] = m[0][3] = 0.0f;
+
+	m[1][1] = 2.0f / (t - b);
+	m[1][0] = m[1][2] = m[1][3] = 0.0f;
+
+	m[2][2] = -2.0f / (f - n);
+	m[2][0] = m[2][1] = m[2][3] = 0.0f;
+
+	m[3][0] = -(r + l) / (r - l);
+	m[3][1] = -(t + b) / (t - b);
+	m[3][2] = -(f + n) / (f - n);
+	m[3][3] = 1.0f;
+}
+
+/** Calculate a projection matrix for a given perspective. */
+static inline void
+perspective(float* m, float fov, float aspect, float zNear, float zFar)
+{
+	const float h     = tanf(fov);
+	const float w     = h / aspect;
+	const float depth = zNear - zFar;
+	const float q     = (zFar + zNear) / depth;
+	const float qn    = 2 * zFar * zNear / depth;
+
+	// clang-format off
+	m[0]  = w;  m[1]  = 0;  m[2]  = 0;   m[3]  = 0;
+	m[4]  = 0;  m[5]  = h;  m[6]  = 0;   m[7]  = 0;
+	m[8]  = 0;  m[9]  = 0;  m[10] = q;   m[11] = -1;
+	m[12] = 0;  m[13] = 0;  m[14] = qn;  m[15] = 0;
+	// clang-format on
+}
+
+static inline void
+puglPrintFps(const PuglWorld* world,
+             PuglFpsPrinter*  printer,
+             unsigned* const  framesDrawn)
+{
+	const double thisTime = puglGetTime(world);
+	if (thisTime > printer->lastReportTime + 5) {
+		const double fps = *framesDrawn / (thisTime - printer->lastReportTime);
+		fprintf(stderr,
+		        "%u frames in %.0f seconds = %.3f FPS\n",
+		        *framesDrawn,
+		        thisTime - printer->lastReportTime,
+		        fps);
+
+		printer->lastReportTime = thisTime;
+		*framesDrawn            = 0;
+	}
+}