console-gl: add opengl rendering helper functions

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

ui/Makefile.objs

@@ -26,9 +26,12 @@ sdl.mo-cflags := $(SDL_CFLAGS)
 
 ifeq ($(CONFIG_OPENGL),y)
 common-obj-y += shader.o
+common-obj-y += console-gl.o
 endif
 
 gtk.o-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
 shader.o-cflags += $(OPENGL_CFLAGS)
+console-gl.o-cflags += $(OPENGL_CFLAGS)
 
 shader.o-libs += $(OPENGL_LIBS)
+console-gl.o-libs += $(OPENGL_LIBS)

ui/console-gl.c

@@ -0,0 +1,168 @@
+/*
+ * QEMU graphical console -- opengl helper bits
+ *
+ * Copyright (c) 2014 Red Hat
+ *
+ * Authors:
+ *    Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu-common.h"
+#include "ui/console.h"
+#include "ui/shader.h"
+
+#include "shader/texture-blit-vert.h"
+#include "shader/texture-blit-frag.h"
+
+struct ConsoleGLState {
+    GLint texture_blit_prog;
+};
+
+/* ---------------------------------------------------------------------- */
+
+ConsoleGLState *console_gl_init_context(void)
+{
+    ConsoleGLState *gls = g_new0(ConsoleGLState, 1);
+
+    gls->texture_blit_prog = qemu_gl_create_compile_link_program
+        (texture_blit_vert_src, texture_blit_frag_src);
+    if (!gls->texture_blit_prog) {
+        exit(1);
+    }
+
+    return gls;
+}
+
+void console_gl_fini_context(ConsoleGLState *gls)
+{
+    if (!gls) {
+        return;
+    }
+    g_free(gls);
+}
+
+bool console_gl_check_format(DisplayChangeListener *dcl,
+                             pixman_format_code_t format)
+{
+    switch (format) {
+    case PIXMAN_BE_b8g8r8x8:
+    case PIXMAN_BE_b8g8r8a8:
+    case PIXMAN_r5g6b5:
+        return true;
+    default:
+        return false;
+    }
+}
+
+void surface_gl_create_texture(ConsoleGLState *gls,
+                               DisplaySurface *surface)
+{
+    assert(gls);
+    assert(surface_stride(surface) % surface_bytes_per_pixel(surface) == 0);
+
+    switch (surface->format) {
+    case PIXMAN_BE_b8g8r8x8:
+    case PIXMAN_BE_b8g8r8a8:
+        surface->glformat = GL_BGRA_EXT;
+        surface->gltype = GL_UNSIGNED_BYTE;
+        break;
+    case PIXMAN_r5g6b5:
+        surface->glformat = GL_RGB;
+        surface->gltype = GL_UNSIGNED_SHORT_5_6_5;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    glGenTextures(1, &surface->texture);
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, surface->texture);
+    glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT,
+                  surface_stride(surface) / surface_bytes_per_pixel(surface));
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
+                 surface_width(surface),
+                 surface_height(surface),
+                 0, surface->glformat, surface->gltype,
+                 surface_data(surface));
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+}
+
+void surface_gl_update_texture(ConsoleGLState *gls,
+                               DisplaySurface *surface,
+                               int x, int y, int w, int h)
+{
+    uint8_t *data = (void *)surface_data(surface);
+
+    assert(gls);
+
+    glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT,
+                  surface_stride(surface) / surface_bytes_per_pixel(surface));
+    glTexSubImage2D(GL_TEXTURE_2D, 0,
+                    x, y, w, h,
+                    surface->glformat, surface->gltype,
+                    data + surface_stride(surface) * y
+                    + surface_bytes_per_pixel(surface) * x);
+}
+
+void surface_gl_render_texture(ConsoleGLState *gls,
+                               DisplaySurface *surface)
+{
+    assert(gls);
+
+    glClearColor(0.1f, 0.1f, 0.1f, 0.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    qemu_gl_run_texture_blit(gls->texture_blit_prog);
+}
+
+void surface_gl_destroy_texture(ConsoleGLState *gls,
+                                DisplaySurface *surface)
+{
+    if (!surface || !surface->texture) {
+        return;
+    }
+    glDeleteTextures(1, &surface->texture);
+    surface->texture = 0;
+}
+
+void surface_gl_setup_viewport(ConsoleGLState *gls,
+                               DisplaySurface *surface,
+                               int ww, int wh)
+{
+    int gw, gh, stripe;
+    float sw, sh;
+
+    assert(gls);
+
+    gw = surface_width(surface);
+    gh = surface_height(surface);
+
+    sw = (float)ww/gw;
+    sh = (float)wh/gh;
+    if (sw < sh) {
+        stripe = wh - wh*sw/sh;
+        glViewport(0, stripe / 2, ww, wh - stripe);
+    } else {
+        stripe = ww - ww*sh/sw;
+        glViewport(stripe / 2, 0, ww - stripe, wh);
+    }
+}

ui/shader.c

@@ -29,6 +29,25 @@
 
 /* ---------------------------------------------------------------------- */
 
+void qemu_gl_run_texture_blit(GLint texture_blit_prog)
+{
+    GLfloat in_position[] = {
+        -1, -1,
+        1,  -1,
+        -1,  1,
+        1,   1,
+    };
+    GLint l_position;
+
+    glUseProgram(texture_blit_prog);
+    l_position = glGetAttribLocation(texture_blit_prog, "in_position");
+    glVertexAttribPointer(l_position, 2, GL_FLOAT, GL_FALSE, 0, in_position);
+    glEnableVertexAttribArray(l_position);
+    glDrawArrays(GL_TRIANGLE_STRIP, l_position, 4);
+}
+
+/* ---------------------------------------------------------------------- */
+
 GLuint qemu_gl_create_compile_shader(GLenum type, const GLchar *src)
 {
     GLuint shader;

ui/shader/texture-blit.frag

@@ -0,0 +1,10 @@
+
+#version 300 es
+
+uniform sampler2D image;
+in  mediump vec2 ex_tex_coord;
+out mediump vec4 out_frag_color;
+
+void main(void) {
+     out_frag_color = texture(image, ex_tex_coord);
+}

ui/shader/texture-blit.vert

@@ -0,0 +1,10 @@
+
+#version 300 es
+
+in vec2  in_position;
+out vec2 ex_tex_coord;
+
+void main(void) {
+    gl_Position = vec4(in_position, 0.0, 1.0);
+    ex_tex_coord = vec2(1.0 + in_position.x, 1.0 - in_position.y) * 0.5;
+}