3 * (C) 2018 by Andreas Eversberg <jolly@eversberg.eu>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
28 #define GL3_PROTOTYPES 1
32 #define MONITOR_DISTANCE 35.0
33 static uint8_t *image_rgb = NULL;
34 static uint8_t *osd_rgba[MAX_OSD] = { NULL, NULL };
35 static GLuint image_name;
36 static GLuint osd_name[MAX_OSD];
37 static int screen_width, screen_height;
38 static int image_width, image_height;
39 static int osd_width[MAX_OSD], osd_height[MAX_OSD];
40 static int texture_size;
41 static int osd_size[MAX_OSD];
44 /* alloc and init an image texture with size that is greater than the power of two */
45 int init_opengl_image(int _image_width, int _image_height)
49 image_width = _image_width;
50 image_height = _image_height;
52 /* generate texture */
53 for (texture_size = 1; texture_size <= image_width || texture_size <= image_height; texture_size *= 2)
56 image_rgb = calloc(texture_size * texture_size, 3);
58 print_error("Failed to allocate texture\n");
62 glShadeModel(GL_FLAT);
63 glPixelStorei(GL_UNPACK_ALIGNMENT, 1); /* bytes */
64 glGenTextures(1, &image_name);
65 glBindTexture(GL_TEXTURE_2D, image_name);
66 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
67 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
68 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_size, texture_size, 0, GL_RGB, GL_UNSIGNED_BYTE, image_rgb);
78 /* alloc and init an osd texture with size that is greater than the power of two */
79 int init_opengl_osd(int num, int _osd_width, int _osd_height)
83 if (num < 0 || num >= MAX_OSD) {
84 print_error("given OSD number out of range");
89 osd_width[num] = _osd_width;
90 osd_height[num] = _osd_height;
92 /* generate texture */
93 for (osd_size[num] = 1; osd_size[num] <= osd_width[num] || osd_size[num] <= osd_height[num]; osd_size[num] *= 2)
95 osd_rgba[num] = calloc(osd_size[num] * osd_size[num], 4);
97 print_error("Failed to allocate texture\n");
101 glPixelStorei(GL_UNPACK_ALIGNMENT, 1); /* bytes */
102 glGenTextures(1, &osd_name[num]);
103 glBindTexture(GL_TEXTURE_2D, osd_name[num]);
104 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
105 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
106 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, osd_size[num], osd_size[num], 0, GL_RGBA, GL_UNSIGNED_BYTE, osd_rgba[num]);
115 /* set clip planes so that the image portion of the image texture is centered and pixels are rectengular */
116 void resize_opengl(int _screen_width, int _screen_height)
118 screen_width = _screen_width;
119 screen_height = _screen_height;
122 void opengl_clear(int _flip_y)
127 glClearColor(0.0, 0.0, 0.0, 1.0);
128 glClear(GL_COLOR_BUFFER_BIT);
131 /* set viewport for improved rendering */
132 void opengl_viewport(int split, int benson_at_line, double fov, double benson_size)
135 int view_width, view_height;
136 int new_width, new_height;
138 /* center view, or put it in the top half of the window */
141 view_y = screen_height / 2;
142 view_width = screen_width;
143 view_height = screen_height / 2;
144 } else if (split == 2) {
147 view_width = screen_width;
148 view_height = screen_height / 2;
152 view_width = screen_width;
153 view_height = screen_height;
156 /* avoid division by zero, if one dimension is too small */
157 if (view_width < 1 || view_height < 1)
160 /* calculate a viewport that has apect of image_width:image_height */
161 if (view_height * image_width > view_width * image_height) {
162 new_height = view_width * image_height / image_width;
163 view_y = view_y + view_height / 2 - new_height / 2;
164 view_height = new_height;
165 } else if (view_height * image_width < view_width * image_height) {
166 new_width = view_height * image_width / image_height;
167 view_x = view_x + view_width / 2 - new_width / 2;
168 view_width = new_width;
171 /* avoid views that are too small */
172 if (view_width < 1 || view_height < 1)
175 /* viewport and projection matrix */
176 glViewport((GLsizei)view_x, (GLsizei)view_y, (GLsizei)view_width, (GLsizei)view_height);
177 glMatrixMode(GL_PROJECTION);
180 /* calculate field-of-view */
181 double slope = tan(fov / 360 * M_PI);
182 /* make frustum to center the view in the game view above benson */
183 double left = -slope;
184 double right = slope;
185 double benson_start_at_position = ((double)image_height - (double)benson_at_line) * benson_size;
186 double top = slope * ((double)image_height - benson_start_at_position) / (double)image_width;
187 double bottom = -slope * ((double)image_height * 2.0 - ((double)image_height - benson_start_at_position)) / (double)image_width;
188 glFrustum(left, right, bottom, top, 1.0, 5000000000.0);
190 glMatrixMode(GL_MODELVIEW);
193 /* render image or only benson */
194 void opengl_blit_image(uint8_t *rgb, int filter, int benson_at_line, int render_benson_only, double fov, double monitor_distance, double benson_size)
196 double texture_left = 0;
197 double texture_right = ((double)image_width) / (double)texture_size;
198 double texture_top = ((double)benson_at_line) / (double)texture_size;
199 double texture_bottom = ((double)image_height) / (double)texture_size;
200 double image_start_at_position = ((double)image_height - (double)benson_at_line) * benson_size;
201 double image_top = -((double)image_height - image_start_at_position) / (double)image_width;
202 double image_bottom = -((double)image_height * 2.0 - ((double)image_height - image_start_at_position)) / (double)image_width;
204 /* calculate field-of-view */
205 double slope = tan(fov / 360 * M_PI) * monitor_distance;
208 glEnable(GL_TEXTURE_2D);
209 glBindTexture(GL_TEXTURE_2D, image_name);
210 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); /* no modulation with color */
211 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, (filter) ? GL_LINEAR : GL_NEAREST);
212 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, (filter) ? GL_LINEAR : GL_NEAREST);
213 if (render_benson_only) {
214 /* render benson only, and copy top line of benson to one line above, so the texture filter will not take false data above benson */
215 rgb += image_width * (benson_at_line - 1) * 3;
216 memcpy(rgb, rgb + image_width * 3, image_width * 3);
217 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, benson_at_line - 1, image_width, image_height - benson_at_line - 1, GL_RGB, GL_UNSIGNED_BYTE, rgb);
219 image_top = -image_top;
221 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, image_width, image_height, GL_RGB, GL_UNSIGNED_BYTE, rgb);
224 glTexCoord2f(texture_left, texture_bottom);
225 glVertex3f(-benson_size * slope, image_bottom * slope, -monitor_distance);
226 glTexCoord2f(texture_right, texture_bottom);
227 glVertex3f(benson_size * slope, image_bottom * slope, -monitor_distance);
228 glTexCoord2f(texture_right, texture_top);
229 glVertex3f(benson_size * slope, image_top * slope, -monitor_distance);
230 glTexCoord2f(texture_left, texture_top);
231 glVertex3f(-benson_size * slope, image_top * slope, -monitor_distance);
233 glDisable(GL_TEXTURE_2D);
236 /* render osd texture */
237 void opengl_blit_osd(int num, uint8_t *rgba, int filter, int benson_at_line, double fov, double monitor_distance, double benson_size, double scale_x, double scale_y, double offset_x, double offset_y)
239 double texture_left = 0.0;
240 double texture_right = (double)osd_width[num] / (double)osd_size[num];
241 double texture_top = 0.0;
242 double texture_bottom = (double)osd_height[num] / (double)osd_size[num];
243 double benson_start_at_position;
244 double osd_left = 0.0;
245 double osd_right = 1.0;
246 double osd_top = 0.0;
247 double osd_bottom = 1.0;
248 double slope, range, center;
252 benson_start_at_position = ((double)image_height - (double)benson_at_line) * benson_size;
253 osd_top = ((double)image_height - benson_start_at_position) / (double)image_width;
254 osd_bottom = -((double)image_height * 2.0 - ((double)image_height - benson_start_at_position)) / (double)image_width;
255 /* calculate field-of-view */
256 slope = tan(fov / 360 * M_PI) * monitor_distance;
258 range = (osd_right - osd_left) / 2.0;
259 center = (osd_right + osd_left) / 2.0;
260 osd_left = (osd_left - center) * scale_x + center + range * offset_x;
261 osd_right = (osd_right - center) * scale_x + center + range * offset_x;
262 range = (osd_bottom - osd_top) / 2.0;
263 center = (osd_bottom + osd_top) / 2.0;
264 osd_top = (osd_top - center) * scale_y + center + range * offset_y;
265 osd_bottom = (osd_bottom - center) * scale_y + center + range * offset_y;
268 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
269 glEnable(GL_TEXTURE_2D);
270 glBindTexture(GL_TEXTURE_2D, osd_name[num]);
271 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); /* no modulation with color */
272 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, (filter) ? GL_LINEAR : GL_NEAREST);
273 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, (filter) ? GL_LINEAR : GL_NEAREST);
274 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, osd_width[num], osd_height[num], GL_RGBA, GL_UNSIGNED_BYTE, rgba);
277 /* perspective viewport */
278 glTexCoord2f(texture_left, texture_bottom);
279 glVertex3f(osd_left * slope, osd_bottom * slope, -monitor_distance);
280 glTexCoord2f(texture_right, texture_bottom);
281 glVertex3f(osd_right * slope, osd_bottom * slope, -monitor_distance);
282 glTexCoord2f(texture_right, texture_top);
283 glVertex3f(osd_right * slope, osd_top * slope, -monitor_distance);
284 glTexCoord2f(texture_left, texture_top);
285 glVertex3f(osd_left * slope, osd_top * slope, -monitor_distance);
287 /* orthogonal viewport */
288 glTexCoord2f(texture_left, texture_top);
289 glVertex3f(osd_left, osd_top, 0.0);
290 glTexCoord2f(texture_right, texture_top);
291 glVertex3f(osd_right, osd_top, 0.0);
292 glTexCoord2f(texture_right, texture_bottom);
293 glVertex3f(osd_right, osd_bottom, 0.0);
294 glTexCoord2f(texture_left, texture_bottom);
295 glVertex3f(osd_left, osd_bottom, 0.0);
298 glDisable(GL_TEXTURE_2D);
302 /* set color and opacity */
303 void opengl_render_color(double r, double g, double b, double a)
307 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
308 glColor4d(r, g, b, a);
316 void opengl_render_polygon(double *x, double *y, double *z, int count, int cull_face)
321 glEnable(GL_CULL_FACE);
322 glFrontFace((flip_y) ? GL_CCW : GL_CW);
326 for (i = 0; i < count; i++)
327 glVertex3d(x[i], y[i], -z[i]);
330 glDisable(GL_CULL_FACE);
333 /* render polygon, but make sure any size of it is visible */
334 void opengl_render_polygon_and_line(double *x, double *y, double *z, int count)
339 for (i = 0; i < count; i++)
340 glVertex3d(x[i], y[i], -z[i]);
342 glBegin(GL_LINE_LOOP);
343 for (i = 0; i < count; i++)
344 glVertex3d(x[i], y[i], -z[i]);
349 void opengl_render_line(double x1, double y1, double z1, double x2, double y2, double z2, double size)
353 glVertex3f(x1, y1, -z1);
354 glVertex3f(x2, y2, -z2);
361 void opengl_render_point(double x, double y, double z, double size)
365 glVertex3f(x, y, -z);
371 /* free image texture */
372 void exit_opengl(void)
380 for (i = 0; i < MAX_OSD; i++) {