Mesa (gallium-mesa-7.4): xdemos: add glsl-tri.c

Keith Whitwell keithw at kemper.freedesktop.org
Thu Feb 19 15:19:33 UTC 2009


Module: Mesa
Branch: gallium-mesa-7.4
Commit: cb9d20d45b90ba22c1803a9634650cda0124ace8
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=cb9d20d45b90ba22c1803a9634650cda0124ace8

Author: Keith Whitwell <keithw at vmware.com>
Date:   Thu Feb 19 13:50:59 2009 +0000

xdemos: add glsl-tri.c

---

 progs/xdemos/Makefile   |    3 +-
 progs/xdemos/glsl-tri.c |  385 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 387 insertions(+), 1 deletions(-)

diff --git a/progs/xdemos/Makefile b/progs/xdemos/Makefile
index 8d248fb..8a03df8 100644
--- a/progs/xdemos/Makefile
+++ b/progs/xdemos/Makefile
@@ -12,6 +12,7 @@ LIBS = -L$(TOP)/$(LIB_DIR) -l$(GL_LIB) $(APP_LIB_DEPS)
 
 PROGS = \
 	corender \
+	glsl-tri \
 	glsync \
 	glthreads \
 	glxdemo \
@@ -50,7 +51,7 @@ EXTRA_PROGS = \
 .SUFFIXES: .c
 
 .c: $(LIB_DEP)
-	$(APP_CC) -I$(INCDIR) $(X11_INCLUDES) $(CFLAGS) $(LDFLAGS) $< $(LIBS) -o $@
+	$(APP_CC) -I$(INCDIR) -I../util $(X11_INCLUDES) $(CFLAGS) $(LDFLAGS) $< $(LIBS) -o $@
 
 
 ##### TARGETS #####
diff --git a/progs/xdemos/glsl-tri.c b/progs/xdemos/glsl-tri.c
new file mode 100644
index 0000000..3920049
--- /dev/null
+++ b/progs/xdemos/glsl-tri.c
@@ -0,0 +1,385 @@
+/**************************************************************************
+ * 
+ * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ **************************************************************************/
+
+/*
+ * Draw a triangle with X/EGL and OpenGL ES 2.x
+ */
+
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/keysym.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>  /* use full OpenGL */
+#include <GL/glext.h>
+#include <GL/glx.h>
+
+
+
+#define FLOAT_TO_FIXED(X)   ((X) * 65535.0)
+
+
+
+static GLfloat view_rotx = 0.0, view_roty = 0.0;
+
+static GLint u_matrix = -1;
+static GLint attr_pos = 0, attr_color = 1;
+
+
+static void
+make_z_rot_matrix(GLfloat angle, GLfloat *m)
+{
+   float c = cos(angle * M_PI / 180.0);
+   float s = sin(angle * M_PI / 180.0);
+   int i;
+   for (i = 0; i < 16; i++)
+      m[i] = 0.0;
+   m[0] = m[5] = m[10] = m[15] = 1.0;
+
+   m[0] = c;
+   m[1] = s;
+   m[4] = -s;
+   m[5] = c;
+}
+
+static void
+make_scale_matrix(GLfloat xs, GLfloat ys, GLfloat zs, GLfloat *m)
+{
+   int i;
+   for (i = 0; i < 16; i++)
+      m[i] = 0.0;
+   m[0] = xs;
+   m[5] = ys;
+   m[10] = zs;
+   m[15] = 1.0;
+}
+
+
+static void
+mul_matrix(GLfloat *prod, const GLfloat *a, const GLfloat *b)
+{
+#define A(row,col)  a[(col<<2)+row]
+#define B(row,col)  b[(col<<2)+row]
+#define P(row,col)  p[(col<<2)+row]
+   GLfloat p[16];
+   GLint i;
+   for (i = 0; i < 4; i++) {
+      const GLfloat ai0=A(i,0),  ai1=A(i,1),  ai2=A(i,2),  ai3=A(i,3);
+      P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0);
+      P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1);
+      P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2);
+      P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3);
+   }
+   memcpy(prod, p, sizeof(p));
+#undef A
+#undef B
+#undef PROD
+}
+
+
+static void
+draw(void)
+{
+   static const GLfloat verts[3][2] = {
+      { -1, -1 },
+      {  1, -1 },
+      {  0,  1 }
+   };
+   static const GLfloat colors[3][3] = {
+      { 1, 0, 0 },
+      { 0, 1, 0 },
+      { 0, 0, 1 }
+   };
+   GLfloat mat[16], rot[16], scale[16];
+
+   /* Set modelview/projection matrix */
+   make_z_rot_matrix(view_rotx, rot);
+   make_scale_matrix(0.5, 0.5, 0.5, scale);
+   mul_matrix(mat, rot, scale);
+   glUniformMatrix4fv(u_matrix, 1, GL_FALSE, mat);
+
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   {
+      glVertexAttribPointer(attr_pos, 2, GL_FLOAT, GL_FALSE, 0, verts);
+      glVertexAttribPointer(attr_color, 3, GL_FLOAT, GL_FALSE, 0, colors);
+      glEnableVertexAttribArray(attr_pos);
+      glEnableVertexAttribArray(attr_color);
+
+      glDrawArrays(GL_TRIANGLES, 0, 3);
+
+      glDisableVertexAttribArray(attr_pos);
+      glDisableVertexAttribArray(attr_color);
+   }
+}
+
+
+/* new window size or exposure */
+static void
+reshape(int width, int height)
+{
+   glViewport(0, 0, (GLint) width, (GLint) height);
+}
+
+
+static void
+create_shaders(void)
+{
+   static const char *fragShaderText =
+      "varying vec4 v_color;\n"
+      "void main() {\n"
+      "   gl_FragColor = v_color;\n"
+      "}\n";
+   static const char *vertShaderText =
+      "uniform mat4 modelviewProjection;\n"
+      "attribute vec4 pos;\n"
+      "attribute vec4 color;\n"
+      "varying vec4 v_color;\n"
+      "void main() {\n"
+      "   gl_Position = modelviewProjection * pos;\n"
+      "   v_color = color;\n"
+      "}\n";
+
+   GLuint fragShader, vertShader, program;
+   GLint stat;
+
+   fragShader = glCreateShader(GL_FRAGMENT_SHADER);
+   glShaderSource(fragShader, 1, (const char **) &fragShaderText, NULL);
+   glCompileShader(fragShader);
+   glGetShaderiv(fragShader, GL_COMPILE_STATUS, &stat);
+   if (!stat) {
+      printf("Error: fragment shader did not compile!\n");
+      exit(1);
+   }
+
+   vertShader = glCreateShader(GL_VERTEX_SHADER);
+   glShaderSource(vertShader, 1, (const char **) &vertShaderText, NULL);
+   glCompileShader(vertShader);
+   glGetShaderiv(vertShader, GL_COMPILE_STATUS, &stat);
+   if (!stat) {
+      printf("Error: vertex shader did not compile!\n");
+      exit(1);
+   }
+
+   program = glCreateProgram();
+   glAttachShader(program, fragShader);
+   glAttachShader(program, vertShader);
+   glLinkProgram(program);
+
+   glGetProgramiv(program, GL_LINK_STATUS, &stat);
+   if (!stat) {
+      char log[1000];
+      GLsizei len;
+      glGetProgramInfoLog(program, 1000, &len, log);
+      printf("Error: linking:\n%s\n", log);
+      exit(1);
+   }
+
+   glUseProgram(program);
+
+   glBindAttribLocation(program, attr_pos, "pos");
+   glBindAttribLocation(program, attr_color, "color");
+
+   u_matrix = glGetUniformLocation(program, "modelviewProjection");
+   printf("Uniform modelviewProjection at %d\n", u_matrix);
+   printf("Attrib pos at %d\n", attr_pos);
+   printf("Attrib color at %d\n", attr_color);
+}
+
+
+static void
+init(void)
+{
+   typedef void (*proc)();
+
+
+   glClearColor(0.4, 0.4, 0.4, 0.0);
+
+   create_shaders();
+}
+
+
+/*
+ * Create an RGB, double-buffered X window.
+ * Return the window and context handles.
+ */
+
+static Window make_rgb_db_window( Display *dpy,
+				  unsigned int width,
+                                  unsigned int height )
+{
+   int attrib[] = { GLX_RGBA,
+		    GLX_RED_SIZE, 1,
+		    GLX_GREEN_SIZE, 1,
+		    GLX_BLUE_SIZE, 1,
+		    GLX_DOUBLEBUFFER,
+		    None };
+   int scrnum;
+   XSetWindowAttributes attr;
+   unsigned long mask;
+   Window root;
+   Window win;
+   GLXContext ctx;
+   XVisualInfo *visinfo;
+
+   scrnum = DefaultScreen( dpy );
+   root = RootWindow( dpy, scrnum );
+
+   visinfo = glXChooseVisual( dpy, scrnum, attrib );
+   if (!visinfo) {
+      printf("Error: couldn't get an RGB, Double-buffered visual\n");
+      exit(1);
+   }
+
+   /* window attributes */
+   attr.background_pixel = 0;
+   attr.border_pixel = 0;
+   attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
+   attr.event_mask = StructureNotifyMask | ExposureMask;
+   mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
+
+   win = XCreateWindow( dpy, root, 0, 0, width, height,
+		        0, visinfo->depth, InputOutput,
+		        visinfo->visual, mask, &attr );
+
+   ctx = glXCreateContext( dpy, visinfo, NULL, True );
+   if (!ctx) {
+      printf("Error: glXCreateContext failed\n");
+      exit(1);
+   }
+
+   glXMakeCurrent( dpy, win, ctx );
+
+   return win;
+}
+
+
+static void event_loop( Display *dpy, Window w )
+{
+   XEvent event;
+
+   while (1) {
+      int redraw = 0;
+
+      XNextEvent( dpy, &event );
+
+      switch (event.type) {
+      case Expose:
+         redraw = 1;
+         break;
+      case ConfigureNotify:
+         reshape(event.xconfigure.width, event.xconfigure.height);
+         break;
+      case KeyPress:
+         {
+            char buffer[10];
+            int r, code;
+            code = XLookupKeysym(&event.xkey, 0);
+            if (code == XK_Left) {
+               view_roty += 5.0;
+            }
+            else if (code == XK_Right) {
+               view_roty -= 5.0;
+            }
+            else if (code == XK_Up) {
+               view_rotx += 5.0;
+            }
+            else if (code == XK_Down) {
+               view_rotx -= 5.0;
+            }
+            else {
+               r = XLookupString(&event.xkey, buffer, sizeof(buffer),
+                                 NULL, NULL);
+               if (buffer[0] == 27) {
+                  /* escape */
+                  return;
+               }
+            }
+         }
+         redraw = 1;
+         break;
+      default:
+         ; /*no-op*/
+      }
+
+      if (redraw) {
+         draw();
+         glXSwapBuffers( dpy, w );
+      }
+   }
+}
+
+
+static void
+usage(void)
+{
+   printf("Usage:\n");
+   printf("  -display <displayname>  set the display to run on\n");
+   printf("  -info                   display OpenGL renderer info\n");
+}
+ 
+
+int
+main(int argc, char *argv[])
+{
+   const int winWidth = 300, winHeight = 300;
+   const char *dpyName = NULL;
+   Display *x_dpy;
+   Window win;
+   GLboolean printInfo = GL_FALSE;
+   int i;
+
+   for (i = 1; i < argc; i++) {
+      if (strcmp(argv[i], "-display") == 0) {
+         dpyName = argv[i+1];
+         i++;
+      }
+      else if (strcmp(argv[i], "-info") == 0) {
+         printInfo = GL_TRUE;
+      }
+      else {
+         usage();
+         return -1;
+      }
+   }
+
+   x_dpy = XOpenDisplay(dpyName);
+   if (!x_dpy) {
+      printf("Error: couldn't open display %s\n",
+	     dpyName ? dpyName : getenv("DISPLAY"));
+      return -1;
+   }
+
+
+   win = make_rgb_db_window( x_dpy, winWidth, winHeight );
+
+   XMapWindow(x_dpy, win);
+
+   if (printInfo) {
+      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
+      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
+      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
+      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
+   }
+
+   init();
+
+   /* Set initial projection/viewing transformation.
+    * We can't be sure we'll get a ConfigureNotify event when the window
+    * first appears.
+    */
+   reshape(winWidth, winHeight);
+
+   event_loop(x_dpy, win);
+   return 0;
+}




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