From 901c744814a4e8098f4aba465af03848c9c5e061 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Sun, 7 Jun 2020 21:52:23 +0200
Subject: Initial commit

---
 window_texture.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 window_texture.c

(limited to 'window_texture.c')

diff --git a/window_texture.c b/window_texture.c
new file mode 100644
index 0000000..f0d89d1
--- /dev/null
+++ b/window_texture.c
@@ -0,0 +1,120 @@
+#include "window_texture.h"
+#include <X11/extensions/Xcomposite.h>
+
+static int x11_supports_composite_named_window_pixmap(Display *display) {
+    int extension_major;
+    int extension_minor;
+    if(!XCompositeQueryExtension(display, &extension_major, &extension_minor))
+        return 0;
+
+    int major_version;
+    int minor_version;
+    return XCompositeQueryVersion(display, &major_version, &minor_version) && (major_version > 0 || minor_version >= 2);
+}
+
+int window_texture_init(WindowTexture *window_texture, Display *display, Window window) {
+    if(!x11_supports_composite_named_window_pixmap(display))
+        return 1;
+
+    window_texture->display = display;
+    window_texture->window = window;
+    window_texture->pixmap = None;
+    window_texture->glx_pixmap = None;
+    window_texture->texture_id = 0;
+
+    XCompositeRedirectWindow(display, window, CompositeRedirectAutomatic);
+    return window_texture_on_resize(window_texture);
+}
+
+static void window_texture_cleanup(WindowTexture *self) {
+    if(self->texture_id) {
+        glDeleteTextures(1, &self->texture_id);
+        self->texture_id = 0;
+    }
+
+    if(self->glx_pixmap) {
+        glXDestroyPixmap(self->display, self->glx_pixmap);
+        glXReleaseTexImageEXT(self->display, self->glx_pixmap, GLX_FRONT_EXT);
+        self->glx_pixmap = None;
+    }
+
+    if(self->pixmap) {
+        XFreePixmap(self->display, self->pixmap);
+        self->pixmap = None;
+    }
+}
+
+void window_texture_deinit(WindowTexture *self) {
+    window_texture_cleanup(self);
+}
+
+int window_texture_on_resize(WindowTexture *self) {
+    window_texture_cleanup(self);
+
+    int result = 0;
+
+    const int pixmap_config[] = {
+        GLX_BIND_TO_TEXTURE_RGBA_EXT, True,
+        GLX_DRAWABLE_TYPE, GLX_PIXMAP_BIT,
+        GLX_BIND_TO_TEXTURE_TARGETS_EXT, GLX_TEXTURE_2D_BIT_EXT,
+        /*GLX_BIND_TO_MIPMAP_TEXTURE_EXT, True,*/
+        GLX_DOUBLEBUFFER, False,
+        GLX_BUFFER_SIZE, 32,
+        GLX_ALPHA_SIZE, 8,
+        None
+    };
+
+    const int pixmap_attribs[] = {
+        GLX_TEXTURE_TARGET_EXT, GLX_TEXTURE_2D_EXT,
+        GLX_TEXTURE_FORMAT_EXT, GLX_TEXTURE_FORMAT_RGB_EXT,
+        /*GLX_MIPMAP_TEXTURE_EXT, True,*/
+        None
+    };
+
+    int c;
+    GLXFBConfig *configs = glXChooseFBConfig(self->display, 0, pixmap_config, &c);
+    if(!configs)
+        return 1;
+
+    self->pixmap = XCompositeNameWindowPixmap(self->display, self->window);
+    if(!self->pixmap) {
+        result = 2;
+        goto cleanup;
+    }
+
+    self->glx_pixmap = glXCreatePixmap(self->display, configs[0], self->pixmap, pixmap_attribs);
+    if(!self->glx_pixmap) {
+        result = 3;
+        goto cleanup;
+    }
+
+    glGenTextures(1, &self->texture_id);
+    glBindTexture(GL_TEXTURE_2D, self->texture_id);
+    if(self->texture_id == 0) {
+        result = 4;
+        goto cleanup;
+    }
+
+    glXBindTexImageEXT(self->display, self->glx_pixmap, GLX_FRONT_EXT, NULL);
+    /*glGenerateMipmap(GL_TEXTURE_2D)*/
+
+    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
+    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
+    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
+    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);//GL_LINEAR_MIPMAP_LINEAR );
+    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+ 
+    float fLargest = 0.0f;
+    glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &fLargest);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, fLargest);
+
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    cleanup:
+    XFree(configs);
+    return result;
+}
+
+GLuint window_texture_get_opengl_texture_id(WindowTexture *self) {
+    return self->texture_id;
+}
-- 
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