add clear depth test

Signed-off-by: Jerome Glisse <jglisse@redhat.com>

2 files changed, 270 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 1f754f1..fa4587b 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CC = gcc
 CFLAGS = -I . -g -O0 -Wall -std=c99 -lGL -lGLU -lm -D_BSD_SOURCE
 
 TARGETS = amd-gpu-name glgears glgears-box glgears-box-cstrealloc \
-	gltransformfeedback
+	gltransformfeedback glclear-depth
 
 all: $(TARGETS)
 
diff --git a/glclear-depth.c b/glclear-depth.c
new file mode 100644
index 0000000..7401f0e
--- /dev/null
+++ b/glclear-depth.c
@@ -0,0 +1,269 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * author: Jerome Glisse
+ */
+#define MAXFRAME        5
+#define PFINISH         1
+#define MAX_PARTICLES   256
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/glew.h>
+#include <GL/glut.h>
+
+static GLuint win_width = 1024;
+static GLuint win_height = 1024;
+
+static GLuint fbo;
+static GLuint renderbuffers[3];
+static GLuint nrenderbuffers = 0;
+
+GLuint generate_simple_fbo(unsigned width, unsigned height)
+{
+    GLuint fb;
+    GLenum status;
+    unsigned color, stencil, depth, packed;
+
+    color = stencil = depth = packed = 1;
+
+#if 0
+    /* texture */
+    glGenTextures(1, &gears_tex);
+    glBindTexture(GL_TEXTURE_2D, gears_tex);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+#endif
+
+    glGenFramebuffers(1, &fb);
+    glBindFramebuffer(GL_FRAMEBUFFER, fb);
+
+
+    if (color) {
+#if 1
+        glGenRenderbuffers(1, &renderbuffers[nrenderbuffers]);
+        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        nrenderbuffers++;
+#else
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, gears_tex, 0);
+#endif
+    }
+
+    if (stencil) {
+        const GLenum format = (packed)
+            ? GL_DEPTH24_STENCIL8
+            : GL_STENCIL_INDEX8;
+        const GLenum attachment = (packed)
+            ? GL_DEPTH_STENCIL_ATTACHMENT
+            : GL_STENCIL_ATTACHMENT;
+
+        glGenRenderbuffers(1, &renderbuffers[nrenderbuffers]);
+        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        glRenderbufferStorage(GL_RENDERBUFFER, format, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, attachment, GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        nrenderbuffers++;
+    }
+
+    if (!packed && depth) {
+        glGenRenderbuffers(1, &renderbuffers[nrenderbuffers]);
+        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, renderbuffers[nrenderbuffers]);
+        nrenderbuffers++;
+    }
+
+    status = glGetError();
+    if (status != GL_NO_ERROR) {
+        fprintf(stderr, "Unexpected GL error: 0x%x\n", status);
+        exit(1);
+    }
+
+    /* All of the possible combinations that we can generate are required
+     * to be supported by all OpenGL 3.0 implementations, with one
+     * exception.  As far as I can tell, implementations are not required
+     * to support separate depth and stencil.  That one option is handled
+     * specially.
+     */
+    status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+    if (status != GL_FRAMEBUFFER_COMPLETE
+        && !(status == GL_FRAMEBUFFER_UNSUPPORTED && stencil && !packed)) {
+        fprintf(stderr,
+            "Framebuffer %s color, %s stencil (%s) was not "
+            "complete: 0x%04x\n",
+            color ? "with" : "without",
+            stencil ? "with" : "without",
+            packed ? "packed" : "separate",
+            status);
+        exit(1);
+    }
+
+    if (status == GL_FRAMEBUFFER_UNSUPPORTED) {
+        glDeleteRenderbuffers(nrenderbuffers, renderbuffers);
+        glDeleteFramebuffers(1, &fb);
+        fprintf(stderr, "Unsupported framebuffer\n");
+        exit(1);
+    }
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+#if 0
+    glClearColor(0.2, 0.4, 0.6, 1.0);
+    glClearDepth(0.5);
+    glClearStencil(0x7a);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+    glFinish();
+#endif
+    return fb;
+}
+
+void vsimple_probe(void)
+{
+    GLfloat *pixels = malloc(256*256*sizeof(float));
+    glReadPixels(0, 0, 256, 256, GL_DEPTH_COMPONENT, GL_FLOAT, pixels);
+    fprintf(stderr, "probed %f\n", pixels[100]);
+    free(pixels);
+}
+
+static void draw(void)
+{
+    static const float first[4]  = { 0.5, 1.0, 1.0, 1.0 };
+    static const float second[4] = { 0.8, 0.0, 0.0, 0.0 };
+
+#if PFINISH
+    fprintf(stderr, "EE CLEAR 0.5 -------------------------------------------------\n");
+#endif
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glClearColor(0.2, 0.4, 0.6, 1.0);
+    glClearDepth(0.2);
+    glClearStencil(0x7a);
+    glClearBufferfv(GL_DEPTH, 0, first);
+#if PFINISH
+    glFinish();
+    fprintf(stderr, "EE CLEAR 0.5 _________________________________________________\n");
+#endif
+
+#if PFINISH
+    fprintf(stderr, "EE CLEAR PROBE -----------------------------------------------\n");
+#endif
+    vsimple_probe();
+#if PFINISH
+    fprintf(stderr, "EE CLEAR PROBE _______________________________________________\n");
+#endif
+
+#if PFINISH
+    fprintf(stderr, "EE CLEAR 0.8 -------------------------------------------------\n");
+#endif
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glClearColor(0.2, 0.4, 0.6, 1.0);
+    glClearDepth(0.2);
+    glClearStencil(0x7a);
+    glClearBufferfv(GL_DEPTH, 0, second);
+#if PFINISH
+    glFinish();
+    fprintf(stderr, "EE CLEAR 0.8 _________________________________________________\n");
+#endif
+
+#if PFINISH
+    fprintf(stderr, "EE CLEAR PROBE -----------------------------------------------\n");
+#endif
+    vsimple_probe();
+#if PFINISH
+    fprintf(stderr, "EE CLEAR PROBE _______________________________________________\n");
+#endif
+
+    exit(0);
+}
+
+static void idle(void)
+{
+}
+
+/* new window size or exposure */
+static void reshape(int width, int height)
+{
+    GLfloat h = (GLfloat) height / (GLfloat) width;
+
+    glViewport(0, 0, (GLint) width, (GLint) height);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+    glTranslatef(0.0, 0.0, -40.0);
+
+    win_width = width;
+    win_height = height;
+}
+
+static void init(void)
+{
+    fbo = generate_simple_fbo(512, 512);
+}
+
+static void key(unsigned char k, int x, int y)
+{
+  switch (k) {
+  case 27:  /* Escape */
+      exit(0);
+      break;
+  default:
+      return;
+  }
+  glutPostRedisplay();
+}
+
+int main(int argc, char *argv[])
+{
+    glutInit(&argc, argv);
+    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE | GLUT_STENCIL);
+    glutInitWindowSize(win_width, win_height);
+    glutCreateWindow("glgears");
+
+    GLenum err = glewInit();
+    if (GLEW_OK != err) {
+        fprintf(stderr, "Error: %s\n", glewGetErrorString(err));
+        return -1;
+    }
+
+    glutKeyboardFunc(key);
+    glutIdleFunc(idle);
+    glutReshapeFunc(reshape);
+    glutDisplayFunc(draw);
+
+    init();
+    glutMainLoop();
+    return 0;
+}